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Hagerman Technology WebLog 2007.Comments?
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Dec 28
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Did a bunch of work today, kinda forget what it was. The highlight of my day
just happened. Been listening to LPs again (yea!), going through a bunch of
old stuff that's been boxed up for decades. Wanna find me the good tracks I
can use for shows. Did I really buy some of this stuff? The Billy Joel
sounded horrible. Yuk. No, I'm not talking performance, I mean the sonics I
can rip off the LP with my Dynavector. Tatto You was ok, better than most. A
lot of stuff I have is just so-so. The Jackson Brown sorta dead and unlively,
but it was nice to play it anyway. Then I find this Brothers In Arms. Shoot,
I don't even remember buying it. The cover and sleeve are near mint. I check
the stamper, SH11 both sides. Hmmm. Drop the needle, and ... very quiet.
Huh? Then pow! Holy crap, I can't believe how solid and dynamic this pressing
is! It is easily as good as anything in my library, 200g re-issues and MoFis
included. Wide open sonics, superb transients and punch. Oh yeah, baby, this
is the way it is supposed to be. Ok, so I got me one stellar piece of vinyl.
I hope I find some more. Gonna run through the entire collection and grade.
So I run through a whole bunch of crud. Why is it most of my old collection
has a dull lifeless sound? It it because there is a stale layer of beer on
them? Or did my Dual 1228 rip them up? The LPs from a certain era of my life
were not treated too well. Who would have guessed I end up here. Anyway, I
get to some new stuff. So I put on one of those 45s from Classic, a Jacinta
track. Wholy sheet! It does get better. These 45s are unbelievable! Quiet,
smooth. Wonderful sound. I have to get more of these.
So I put the Dire Straights back on, just to make sure I wasn't hallucinating.
Yep, got the whole body goose bumps again. Incredible musical buildup at the
start of that MTV song (money for nothin).
Dec 27
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Already thinking about next generation FRYKLEANER. The FRYBABY is nice, but
the form factor for the FRYGOLD seems to be unpopular. Either that or the
burn-in craze has greatly diminished. So I thought of what the next model
should be. I think the VACUTRACE chassis is perfect. So the smaller one is
even better. Rugged and portable. Easily stored. Can make with very nice
finished panel. I think more output power is worth a try. Have this idea to
use an LM1875 audio power opamp to drive a tranny. Center-tapped secondaries
will then boost voltage and drive differentially, with no local connection to
ground. It'll have two controls, one for amplitude (MC, MM, LINE, and CABLE).
The high power CABLE setting should be able to deliver roughly 5x the power
over a FRYBABY. I think 10Vpp between conductors. Other control is a mode
switch (OFF, VOLTAGE, CURRENT), so you don't have to play games with various
cable hookup methods. Let a switch determine voltage or current mode. One
drawback is that I can't use a wall wart, as it won't fit inside the closed
cover. But a power cord will! So will have internal ac supply. Has XLR
outputs, phono levels (of course). And the new feature will be an outlet for
burning in power cords. A very versatile design. Small. Way more power. A
good set of specs for a new generation. Ar ar.
Meanwhile, ordered a bunch of production parts. Trying to build this whole
line prior to launch. So I think I will delay website until I can get actual
photos of the finished items. Looking at everything to see where I can
possibly upgrade or make common with another machine. Sent out RFQ for
production chassis parts too. Might as well get batch #1 in house. It'll help
speed up prototyping, like the DA-10.
Since I re-did the Cinemag SU-10 yesterday, thinking if I really like their
iron, then I can use it in PL-10. Or at least in a redesign of the COMPRESSOR.
No reason that machine can't be redone in the image of the new VACUTRACE or new
FRYKLEANER. It'll be a real standout machine with that form factor. Exactly
what you need to break into a new market.
Looked into remote controls. I'm thinking all these fancy plastic moulds look
cool, but are not heavy enough. I like the solid, weighty remotes. And this
one will have panache. Sadly, I limit myself to no custom milling of billets.
Maybe later. For now, I'll copy the PI-10 and SU-10 concept. Black painted
aluminum casting for bottom, red anodized panel on top. Will look ok, not
spectacular. Will feel pretty good, though. I fired up the new band saw and
cut out a few wood blocks to check out various sizes for palm fit and feel for
knob control. I think I'll do the 2" x 4" x 1". Should be a really good
visual match with the other components.
Dec 26
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I redesigned the SU-10 (step-up tranny) to look just like the PICCOLO (PI-10).
That other chassis, however nice, was just adding too much cost. So I'll make
the same top panel, same size as the PICCOLO. In fact, I'm upgrading RCAs on
the PI-10 too. This is cool. I will now have two MC step-up devices, roughly
the same cost, looking alike, but of course one active the other passive. I'll
have LO-MED-HI loading switch to kick in resistors on the secondary. So I'm
going to try LO-MED-HI gain switch on the primary. Not that I really like to
have switch contacts on phono signals. It's worth a try, if I can get the
right metallic junctions. My Cinemags came in already. Just need to order a
panel and wire them up.
Working on an offset-nuller for the PICCOLO. I neglected to realize that any
dc offset on the output could be a problem for some SS phonostages (maybe I
work too much in tubes?). The simple fix is to add 10 ohms in series with R10.
But I want to take that farther. So something like a pot in parallel with R11
would be better. Take a 2.21k from the source of Q3B to the wiper of a 10k
pot, which then ties one leg to VEE. This gives an adjustment range from 217
ohms to 200 ohms. Should be very easy to dial in a zero. No need for those
pesky 10-turn pots, either. I think a simple hot glue of the pot right under
Q3 (oither side of board) is ok. However, the battery holder standoffs will
have to be much taller. At least 1/4".
Ok, finally got the VACUTRACE manual updated. Machine back on the website and
ready to go. I have this first unit that has minor cosmetic defects, that I
can give a discount for.
VACUTRACE new!
Dec 24
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Catching up with production. Even today I shipped out 5 items. Gotta go fill
some stockings now...
Dec 21
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Ok, I am alive again. Somewhat. Taking a while here to recover. So instead
of doing the things I should have been, I layed out the DA-10. Yeah, it wasn't
next on the schedule. But I was thinking. I really need this for myself. No
more CHIMEs in the house. And I had already figured out the new style power
supply design. So I churned out a schematic and did a proto layout. Should be
an easy build. Just like an HA-10 with HAGDAC onboard.
So I was thinking, what can I do to improve on HAGDAC? What can be upgraded?
Well, there wasn't anything I could find. That's a first. No better part to
use. Only possibility are the output connectors. The one change I will make
so it fits the DA-10 is to change the pullup resistors on the comparator
outputs from 4.7k to 1.5k. That way they can directly drive the LEDs. I don't
need any extra stuff on the DA-10 board. Front panel is blank, with 4 LEDS.
Low voltage, high voltage, USB ok, and PLL lock. If they are all on then sound
should come out. Oh wait, if I could, I would change the linear regulators on
the HAGDAC to the discrete type I came up with for the HAGCLOCK. They are very
nice and high performing. But can't because their dropout voltage doesn't work
in this case.
Anyway, the layout came out great. Routed easier than I expected. Suprising,
since I did an unusual arrangement for the chokes. I ran the B+ down the
middle and the heaters on either side. But instead of a single tranny for
heaters, I used two of them. It is a psuedo center-tapped connection. Both
are full wave but outputs cross the board to feed both sections of chokes. I
get both +6V and -6V heater supplies at 0.5 amp. This requires 11 mH of choke,
so I run two 155B 6mH chokes in series on each side. At 25% of capacity their
actual henries will be higher. Shux, that takes six chunks of iron to make a
relatively low power (6W) +/-6V supply. Believe me, this is the most expensive
way to do it. It is also the only one that will give clean power factor and no
switching spikes, inherent voltage regulation, soft start, and zero feedback.
Add 40,000uF of capacitor to each side and voltage ripple should be a mere
11mV.
DA-10 layout
As you can see, with 3 chunks of iron for B+, this board will weigh about the
same as a CASTANET, with 9 chokes and trannys. All super clean passively
regulated supplies. The outputs are 7788 fed by a simple no feedback CCS at
15mA. Hence, the B+ is identical to CASTANET. Tubes wired in triode mode for
lots of gain. Should deliver about 2Vrms full scale at 1.5k output impedance.
That's awesome, and I did it without using the cathode follower. So that's
improvement #2 over the CHIME. Even with the same HAGDAC, this should sound a
little better. Only thing is, you can't roll tubes as easily. Not so many
brands of this type. My one concern is induced hum. I have all the chokes
wired out of phase to magnetically buck each other, and cancel far field. I
also put them as far away and at the 45 degree angle to the chokes on the
HAGDAC. Even so, I might get a magnetic coupling beween supply and IV filter
chokes. We shall see. I maximized spacing. Nothing is for free. To get that
truly organic music, you have to pull out the stops.
Oh yeah, I also had to not route the outputs all the way to back. I decided to
just use coax wiring. It's not a big deal. Just takes a little longer to wire
up.
Here's the final draft of schematic. It looks hideously simple. Exactly!
That's the whole point. Yet it belies the hidden sophistication. Much, much
more going on in there than meets the eye. This is the culmination of 10 years
of tube audio design (plus 15 more on non-audio). This should be the best DAC
I can design from a topology standpoint.
DA-10 schematic
Dec 18
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Oh man, just got the worst food poisoning ever. Today I am drained. Not gonna
work. But I will get KOs order in the mail.
Dec 17
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Spent more time listening last night. Finally. This rig is really starting to
open up. I am getting really good micro details and the ability to hear deep
into a recording. Mostly, I realize that the separation between instruments
and voices has taken a big step forward. This is exactly what I heard at
Thom's with his X-1S. Each sound within the mix remains distinct and does not
mix or get congested together. Oh, and I'm an idiot. That wasn't Aja, it was
Gaucho. Duh. This time I played the entire Crime of the Century. It was this
album that got me hooked on hifi in 1976 at some shop in Minneapolis. Might
still have a lack of overpowering slam. I think there is still more room for
that extra punch. The upgraded capacitors in the CO-10 really help with the
tonality and detail, adding no smear. The notes have no overhang. Very fast
transients and timing is dead on. Had to lower VTA a little for improved
tracking. Bass falls off a little in amplitude, but the articulation stays.
The good news is that this is the first time I've ever been able track this LP
properly. It now made it through. I don't know if that is due to the VTAF or
the 20XL. I also have the new rack with spikes. And new wiring.
Oh, as far as the VTAF, I grossly overestimated the slop in the bearing. Yes,
it has some lateral shift and can tilt, but it is not as big as I thought.
Carefully measuring with a dial calipers I got 0.992 for the threads and 0.998
for the sleeve. That leaves a gap of 0.006. Exactly what Pete said it should
be.
Spent half the day just going through minro design details of the new product
line. Trying very hard to give each piece a common look, such that they all
appear to have been designed at the same time and for the chassis style, even
though they all come from widely different backgrounds. Shifting connectors,
lettering, etc. 1/4" this way, then that way. Make sure all of the lettering
is common in approach. It is working. The lineup of TR-10, CO-10, and SU-10
all look about the same when side by side. FL-10 (FLUGELHORN) is a little bit
of an oddball, in that logo placement doesn't line up perfectly with the HA-10
and other of the new machines. You do the best you can. PI-10 is the old
small box chassis, another oddball. Also, the wife made me go back to yellow
lettering. Anyway, put everything on a shelf and they are all HAGLABS. All
red faces, yellow lettering, same logo, black covers. Common ac plugs,
switches, connectors, yellow LEDs, etc.
Even the VACUTRACE now looks similar. Even has the HAL logo, but I will
initially start selling it again from HAGTECH.
Dec 16
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Did a quick check on SNR for the new CORNET. Hmmm, not so great. Hooked it up
to listen and mostly hiss with no input, but hum when shorted. Aha! The new
power tranny is in a nasty orientation. I forgot the original was aimed for a
perfect magnetic null along the line of tubes (which is also why they were in a
line). Ay, the new tranny spews mag field right across the board and inputs.
Fortunately, they are pretty far away, so a little re-wiring of the input
section is all it took. So now, with a minor EQ tweak and the re-wiring, the
gain is 45dB and SNR 75dBA referenced to 5mV input. That would be 0.9uV of
input referred noise. Pretty good for tubes.
Oh yeah, I also tweaked my CASTANET by putting 0.22uF ppfmx caps in parallel
with the 3.3uF output caps. My system is now the 20XL on a P3 with VTAF into a
PI-10 / CO-10 / HA-10 and Sennheiser HD600. Thinking I should rename the new
CORNET to CO-10. Then also the PI-10 and TR-10 (TRUMPET). It sorta makes
sense. Yes, I am having trouble naming things.
Anyway, I added 1/4" nylon standoffs to my 20XL, such that the VTA can now be
adjusted both positive and negative. Not sure this is a good thing sonically.
Nylon is a bit damped. Methinks I lose some of the rigid coupling to the arm.
It also puts the stylus much lower that the vertical bearing axis, thus causing
velocity modulation on warps.
RB300 standoffs
Finally, I am back to listening. Off the bat this is quite good. Way better
than the setup I had in the lab, which was lifeless and thin. First I did the
test record and adjusted antiskate. Was able to track all of the tracking
tests. The +14dB antiskate test was too much, however. +16dB really booched
it. Ok, it ain't perfect. On some familiar records I tried adjusting VTA.
Really expected to hear change in volume, or tone, or vocals or treble. What I
got was mostly a change in bass articulation. High it got wooly. Low and it
was thin (yes, it was thin in the lab!). Middle wasn't too hard to spot.
Really didn't have to change it much between records. So I dig into my library
and pulled out some LPs I've never heard. The Heifetz on LSC was ok, but
lacking in excitement. I must not be there yet. Also, overall I am missing
that last bit of slam and dynamic control. Tried an old Doc Severinsen. Nice
tunes and great playing, but zero bottom end. Like it needed a different EQ.
Then I tried my copy of Beatles 63-66. Oh my. Lifeless, boring. Vocals were
receeded (could be polarity?). Wondering how far off I am. Getting worried.
Threw on Aja, and voila! It all came back. Solid, thumping bass with control,
decent dynamics (not perfect yet), and wide open sound. And this was an
original. Maybe I don't need the re-issue? So good LPs sound really good.
The bad ones sound bad. Overall, the noise floor is fine, zero fatigue, easy
to listen to without tiring at all. It sounds good both loud and soft. I
think I'm going to play all of AJA now. See ya later.
Dec 14
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Buying tons of parts today. That's just the way it is. Making good progress
on parts lists and pricing. Then I was thinking about the cute little chassis
I bought to match the other HAL stuff. The PICCOLO didn't fit, so it stays the
same, mechanically. But how about a step-up tranny? Ok. So I am buying some
of the Cinemag trannys that so many people like. I'll wire them up a little
differently, because I don't want switches or jumpers on the primaries. Then,
in order for them to mate better with some carts, I'll add a loading switch on
the scondary. Right now the tranny is for 50k loading. This limits you to
certain turns ratios. To get the super low impedance carts you run 1:36 gain.
Maybe bandwidth starts to suffer. So instead, I'm going to try variable
loading on the secondary, in parallel with the 47k of a phonostage. So two
gains, 19dB and 25dB (separate RCA jacks). Three loading settings, LO, MED, HI
(47k). This should result in some useful combos. I'll build one and try it
out myself. Besides, I don't have a step-up of my own right now.
And so I got the CORNET-HAL up and running last night. Tweaked on resistor
values to bring it into proper bias and operating points. Runs perfect! I do
need to make some standoff and board position adjustments, but otherwise this
thing is ready for production. Listened to it. Super quiet. The noise floor
when used with the PICCOLO was superb. I had to crank it up way past a loud
listening level for it to be heard. But even more important was how the groove
noise itself during play was remarkably subdued. I'm not sure why this is,
but it is a great sonic feature of both the CORNET and TRUMPET. Quiet during
play. The coloring is wrong on this unit, so I will keep it for myself. This
will now be my main phono for listening. Combined with the HA-10 (yeah, I'm
keeping unit #1) it makes for a great way to test out the new SU-10 (step-up)
proto. Yeah baby, starting to get close to production. I'll have to put in
a huge order to Hammond one of these days. Ok, now working on resistor
upgrades to these phono stages.
Compiled a new parts list for VACUTRACE. Each part price had to be updated, as
I was working with numbers from seven years ago. This design sure can stand
the test of time! Anyway, the pricing comes out to $1499 from HAGTECH, even
though it has the HAL logo. That's the OEM direct pricing. Two boxes, one is
portable VACUTRACE (close the lid with carrying handle) and the other is a
smaller carrying case for the adapter cards. Price for the SU-10 is high, at
$1500 retail. More than double a PICCOLO-HAL! But hey, that's what it costs.
I don't fudge the numbers. It costs what it costs. (Note, if I sold the new
VACUTRACE through dealers it would be $3000 msrp.)
Dec 13
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A check at my web stats. I get about 2000 page hits per day (1000 visitors).
Roughly 1000 hits per week on my blog! Hey, that must be some sort of
milestone? Most people come from google. Then asylum, audiocircle, diyaudio,
audiogon, in that order. And many more. Hey, I even got a few referrals from
slimdevices.com! Most of you come from comcast.net. 49% are using internet
explorer, 76% run xp, 9% mac, and only 6% vista. One of you is still using
win95.
For a long time I've been wondering about my selection for microprocessor to be
used in the PL-10. I love the PIC line, used them before, and rave about the
Harvard achitecture. They are easy to program, and now have the option of
using C. To me, they are a perfect bridge between code and hardware,
especially analog hardware. Hard to explain. Anyway, the problem is that they
have a gazillion choices. What to pick that won't go out of production? Or
that is in stock. Or popular. I finally narrowed it down to a 16F687, based
on my requirements, mostly pinout and functions. Seems perfect. But how long
before it is discontinued? Well, allay my fears. An article in Nuts&Volts
covered this subject, and the author (rabid user) picked the 16F690 and one of
his prime choices. Turns out it is exactly the same part but with larger
program memory storage! And then, double checking on the microchip.com site,
I see the 690 as a featured item. Bingo. I just upgrade to the 690 and my
choice is safe. Not to get a development kit.
Here's some shots of the new CORNET-HAL. Small, very solid unit. This chassis
wraps around the board very tightly, making it one of the smallest tube phonos
to hit the market. I'll be painting the covers black. The silver panels was
a possible alternate choice for color schemes. Will likely need some resistor
changes in the power supply, as this tranny has a bit more B+ voltage than the
original.
CORNET-HAL frontCORNET-HAL backCORNET-HAL guts
All wired up and ready to go. Meanwhile, I fired up the VACUTRACE, but for
some reason the heaters didn't kick in. Maybe a problem with the board, or I
didn't get the connector fit just right. Making mechanical changes to washers
and standoffs to recreate the perfect fit (this panel is much thicker than the
last one. Should have this done tomorrow. Anyway, it looks something like
this:
VACUTRACE (new)VACUTRACE guts
Now I need to work out pricing. Should I include a small tandem case to carry
the adapter cards? Or is that too much? Do I make the jumper card standard?
One thing I did notice, in a dimly lit room, the yellow lettering smokes! It
comes alive and all of a sudden looks better than the other alternatives. My
preference for the raw engraving is a bit harder to read. It also has a mirror
effect when it catches the light just right. Different. But maybe too out of
the box? I need to make these machines please you, not me. I have to admit,
the yellow does grow on you. The raw silver is stunning at first, but then
perhaps the illusion wears off a little. I still like it, but not sure which
is best for HAGLABS. They are both out of the ordinary.
Dec 12
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Built the CASTANET, took photos, finished the manual. Started shipping them.
Ok, so I ran out of fuse clips, but I still got a bunch out the door. They
look great and build easy. Except for the part about the phone jack mounting,
which requires a bit of balance. Anyway, finally. I was really expecting to
be here a month ago.
Catching up on all production, trying to get machines there by xmas!
Meanwhile, I can get back to finishing the new VACUTRACE, CORNET, and TRUMPET
protos. All of which are 80% to 90% complete. Also have most parts in for a
new ARCHIVER, a project that was cancelled, to be replaced by the FLUGELHORN.
It still helps me debug fit for the OEM version of ARCHIVER (black with silver
knobs & lettering). Once these are done, I should be ready for production of
the HAL units (spending even more money on inventory). And when I find some
spare time, I'll do the relayout of PA-10.
Dec 11
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Spending a lot of time putting together accurate parts lists for the new
products. It's the only way to know how to price things. At the moment, the
expected retail prices (with dealer markup) are:
HA-10 $2100
PICCOLO-HAL $600
CORNET-HAL $2150
TRUMPET-HAL $3400
FLUGELHORN $2150
Suprising how the three machines ended up costing almost the same. I'll likely
offer a 30% discount on all machines until I get some dealers signed up. So
far, all of these products are starting to look killer. Especially the CORNET-
HAL. It will be very compact, and with all of the part upgrades (especially
caps) it is a steal. That's $1505 for a tricked-out CORNET in fancy chassis,
with introductory discount. The FLUGELHORN is also turning into a nice unit.
I realized that I didn't purchase a gazillion ARCHIVER boards, so I am not
stuck having to chop them up. In fact, I can re-design the board to be shorter
and easier to wire up. The board then only costs $33 a piece, even in low
quantities. The original ARHIVERs will then be used for a special OEM project.
So much building going on. I'll be happy to get some of these operational. At
least to the point where I can take photos and start up the website. The whole
HAGLABS movement is finally converging upon a solution. Been working on it a
long time. Wrote the original business plan 1.5 years ago. If you go back in
the blog you'll see I spent a lot of time talking and fretting about it. Never
had any real forward momentum until I started the CASTANET. It gave me the
new chassis style and a low-volume ramp-up solution that I could actually
afford. So this is very exciting for me. Almost ready to exit the tunnel.
Years in the making.
Wow, I just realized what a bargain the TRUMPET-HAL is gonna be. It didn't
cost me too much to make all these chassis changes, which I thought would be a
problem. Tons of work putting one of these together, though. Not bad really,
a TRUMPET-PICCOLO combo for $4k. That is a LOT of machine.
Ok, CASTANET boards came in! Yippee. Now to pick up oarts at the post office
and I can built it up. Take the photos. Finish the manual. I expect to ship
all pre-ordered CASTANET kits by the end of the week. Just in time.
Customer emailed me saying Jack Elliano at Electra-Print made him some custom
headphone output trannys to replace the 119DA he was using. Said they sounded
great. Could be a possible upgrade? I didn't see anything at Jack's site
about them, but maybe somebody can tweak him. Imagine if it had the same
footprint! So I browsed his site a little. Checked out the DRD (direct
reactance drive), as I didn't know what it was. Wow, brilliant! I love the
concept. Not the only answer, but extremely clever.
Electra-print
I got some new panels in. HAL red but with no ink for the lettering. They
look absolutely STUNNING! Gorgeous! This is the breakthough I was hoping for.
Superb appearance, this is going to work great with black painted top and
bottom covers. Dang! I just showed it to my wife. She doesn't like it.
Said "go back to yellow". Shoot. I liked this better. It is more me.
Dec 10
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After I got all production out of the way (folks don't wanna wait for their
machines prior to xmas), I got back to the P3. I read the VTAF website and
apparently the loose fit is on purpose. Personally, I don't like it, as the
slop gets taken up during play, with the needle pulling the bearing to one
side. This will slightly affect setup. So I changed it. Applied several
coats of nail polish to the inside of the sleeve. That took up most of the
slack. It is still loose, but much less play. No idea if this is better or
not. Then I'm thinking, hmmm, the VTAF adds 1/4" under the arm at its lowest
setting. If the arm is already set for average playback with average cart,
then we're off automatically by 1/4". Well, with cart installed, and my 20XL
is on the tall side, the arm still would not make level. The instructions say
to put shims under the back of the cart to tip it backwards. Is that a good
thing? Instead, I added some fiber washers as spacers. Now the cart hangs
down below the headshell on these small standoffs. Ok, still not level, but
pretty darn close. Certainly cannot do negative VTA. Maybe I need a thicker
mat.
Since the machine was apart, I also went ahead with other changes. Added the
matching counterweight. Very nice looking. But I was not able to unscrew the
original stem off the RB300. And no way was I going to wrench it. So had to
put the counterweight on it as is. Diameter is a little off, but with the set
screw I didn't see a problem. It snugs in place. Original just used o-ring
squeeze, which adds some damping & isolation. Ok, now I put on the dust cover
and shit, it hits the counterweight! The VTAF is so tall I can no longer close
the lid. Fortunately, I have me a CNC machine a few feet away. So I ground
off the top of the counterwieght. It now hangs low and with slightly less
mass. But hey, I can now close the lid. And it looks sort of cool, too.
VTAF installation
Lastly, I made a new wiring harness. Decided to stick with coax for now. Made
it silver plated copper & teflon. Two coax twised together with two black
ground wires. Arm ground is now separate from signal. Man, the wire inside
the Rega arm base must be AWG infinity. That's the skinniest wire I ever
worked with. And short! I thought for sure I would be sending this arm out
to get rewired. By some miracle, I got it, no shorts or breaks. I did,
however, have to use hot glue to insulate the bare solder connections. Not my
favorite dielectric. Also changed the clips. Cable not burned in. Just go
with it. Finally, table is back together, ready to tune.
As a side note, all of these upgrades that people do, isn't it just cheaper to
buy a better table in the first place? I think so. Maybe next time I just get
a VPI Scout. Save me some aggravation.
Fired it up on a RIPPER (other stages not ready) with PICCOLO front end. Best
it seemed to run at 26dB. Anyway, the sound was already waaay better than what
I had. Not sure exactly which of the changes made the difference, but it was
back to music, full range. Messed for awhile. I was hoping to find that
magical VTA null everybody talks about. Nope. Never heard it. Gets a little
sloppy and wooly when high, not too bad when low. Really, not the huge changes
I was expecting. Put on the test LPs, ran a VTA test. I still couldn't come
up with an optimum. Reset anti-skate according to the high level tracks (at
least that was easy). Also noticed that I got best tracking performance with
VTA set to minimum. Yeah, maybe the arm is still too high? Once I got the
protractor and balance tweaked yet again, it seemed to balance out a bit.
Music was pretty good, but not up to what I expected. Bottom end is still a
little on the wild side. Maybe my ears are tin. Why can't I hear that optimal
setting? Is it because I am listening through headphones?
The jury is still out for me. Honestly, I was hoping I could do a rave review
here. But considering the challenges of installation, this is not for
everyone. You have to drill a clean hole. There is an immediate 1/4" deficit.
The bearing has too much slop for me (perhaps on purpose)? The parts are
nicely made, I'm just not convinced yet this is the best way to go for a P3.
Much more appropriate for a custom table or arm board.
Dec 09
------
Finally got the last of the CHIME GOLD machines up on auction. Just in time
for Christmas.
Audiogon
Started modifying my Rega P3 for the VTAF. Whoah, it says here you gotta drill
a 1.25" hole. Ok, I guess this is a one-way street, once you commit that's it.
Went to store and bought a 1.125" bit. Damn! Back to store and got the 1.25"
bit. Plinth drill very nicely on my press even though it started as a 1" hole.
Came out reaaly nice. Only $5 for the bit. Now I find the VTAF has the arm
sit in the bushing via gravity, nothing else holding it in place. Hmmm. Hey,
maybe it sounds better that way. I'm a little concerned with the bearing slop,
it has about 0.01" inch play and slop, can chatter. Also re-wiring the arm,
but that's a whole new can of worms itself. I have to make a new "plug" for
strain relief. I'm leaving the wire inside the arm in place for now. And
separating the ground lead from the signal cables. Interestingly, I may have
accidentally discovered a Rega secret. The plinth has hidden cavities! Top
is solid MDF, covered with veneer. Bottom has several internal cavities,
covered up by the veneer so you don't know they are there. Maybe this is
resonance control? Just run your fingernail along the bottom surface and you
can hear exactly where the cutouts are.
Dec 08
------
Was looking at my FLUGELHORN proto, flipped the rear panel upside down in order
to get RCAs on the proper side. When I realized the wood pieces I have to
temporarily hold things together ain't such a bad idea. For the PA-20, which
has to be taller, I could use wodden side panels! That would be both cheap and
very nice looking. Better than a red strip. Of course, this has the problem
of maintaining electrical contact betweer all of the chassis pieces. Real
important. So maybe meet half way, use the normal extrusions to hold things
together (and PCB), then add a wood trim piece for visual appeal. Yeah, I like
it. Can't wait to get time to put into that 20W amp.
Dec 07
------
So I counted the number of names in my customer list. Those who have paid for
something. 1739 different customers. Is that good or not? Seems like a
pretty big number to me. A lot of them repeat buyers. Hey, it's a good start.
Everybody wants hi-res downloads cheap, right? Gave a try at this musicgiants
website. Fine, made account, put in some money, downloaded some songs. Did
the DRM thing. Hey, they play fine on WMP. But I don't want WMP, I want to
play in foobar with my asio stuff. Ok, I want bit perfect playback, none of
that kernel resampling crap. Well, the website is nice, easy to use, the songs
downloaded handily. Fast, too! Took me a LONG time to find out where they
went, as my XP machine registry is quite a bit messed up. Had to use WMP to
find them. Made copies, put into MyMusic. They will NOT play in foobar. Nor
can I convert them into FLAC. Am I stuck in WMP? Maybe I can burn to CD and
then rip & convert? If these hi-res files only play on WMP, then what's the
point? I'll keep you posted on progress. Right now I need help.
Boy, can it rain here or what. At times we can get an inch per minute. You
gotta see it to believe it.
Best way to envision a new product is to build a proto. So I put together a
FLUGELHORN today. Took my panel design and kludged together what it might look
like. Seems like its a fit. Just run wires from front to back. Oops, I just
noticed I put the RCAs on the wrong side. They should swap places with ac
input. I could probably lose the gain trim. But it looks nicer this way. And
I like to use it as a volume control. Trying out some different coupling caps
(blue). Will do an A/B with a normal ARCHIVER when I get a chance.
FLUGELHORN proto frontFLUGELHORN proto back
Got my copy og HIFI+. First couple of pages I see the new phono stage by
Emille. Wow, looks a lot like the new TRUMPET in size and configuration (yet
their circuit is curiously closer to a CORNET). Nice looking boxes.
Emille phono
Oh yeah, I noticed the DRM and other stuff on the musicgiants site might make
it so you can only playback on the computer that did the downloading. Ay. My
music servers are separate from the machine I download to. Is that going to be
a problem? Solved it! I burned all the songs I bought to CD. From there I
can convert to flac and run on my music servers. Yippee! And the CD ends up
being a nice backup, to boot.
And now this paper slide rule falls out of HIFI+. System diagnostic. Shit!
It says my stuff is WAY less than low quality. Crap. I don't even make it to
the bottom of the chart. Maybe I should just give up.
Dec 06
------
Six of the trees in my yard blew down the other day. The soil is not deep here
(hey, we live on the side of a volcano) and the trees adapt to the trade winds.
So they all grow up leaning west. Great, now a storm wind of 75mph blows east.
I have most of them propped up with ropes. They look ok, but confidence is not
very high.
Updated the PA-10 schematic. Lots of changes. New driver tube, new CCS, etc.
Just to give you some idea of the debugging process, here's a copy of the
original schematics marked up with lab notes.
PA-10 original schematic
And here is the revised version. I still need to update reference designators.
PA-10 schematic rev b
I agonize over the thought of trying to re-wire the layout. It's gonna take a
ton of work. Super tight fit. Guaranteed I will run into size problems. The
big 3.3uF film caps I added are huge. Well, each part is key to the design. I
don't add stuff if it ain't needed. I would much rather try and deal with 1uF
caps instead. Also, I am raising the voltage on the electrolytics to 450V, in
the case it gets powered up without tubes. No load condition swings the power
supply up to almost 500V. I need to withstand the surge. CCS have changed.
The output CCS are now separated from driver stage (layout consideration). Not
perfect, as they are self-biased from their own output (3mA). They should stay
reasonably well matched if the transistor betas are close. Added the LEDs to
indicate if each tube is operational. Anyway, it is still the Hagerman self-
balanced output stage. No adjustment required. I'm thinking you could plug in
a 300B or 45 into one of the spots and it would still run. Balanced! It runs
unbalanced at 1/2 power with only one output tube. Not recommended. With
these changes, I think the BW will go up a little, noise will go down.
Actually, all specs should measure superb except for HF response. That will be
on the low side, yet wonderfully behaved.
Ok, did some more photoshop on the self portrait. I kinda like this version
the best.
Psycho
Sometimes I am just out of control. I mean, my designs can really go in
circles, taking wildly different directions. What happens is that I come upon
a working solution, but later realize I am not happy with it. Something just
not right. Such is the case with the ARCHIVER. It's a beautiful stage with
great sound, super capability. I put a TON of work into that design. But so
far it doesn't sell. Maybe it is the chassis? Assembled RIPPERs are no longer
selling either, indicating the market for USB recording has been lost to
competitive offerings. Ok, so my idea was to remake the ARCHIVER into a RED
HAGLABS product, add a BUGLE power supply, better chassis. Well, my solution
(presently being fabricated) is ok. Chassis is plastic (very nice looking) and
big. I got the entire board in there. Chassis is like 18" x 4" x 8". Most of
it hollow. Maybe it is ok. However, every so often I stop to ponder. And
tonight I realized that most of an ARCHIVER will fit into the new red chassis,
same one as HA-10 (CASTANET). It's a far better chassis, is a perfect match
for the other components, and ends up being cheaper overall! The tradeoff is
that I lose the dual inputs, no mono switch. I replace the wall wart with a
real ac power supply. More voltage, more headroom. The rest of the controls
stay. It all fits rather nicely. A compact ARCHIVER. All I have to do is
slice the board into three pieces. The panels look something like this:
RED ARCHER panels
I don't know what to really call it. So far it is the ARCHER. Maybe it should
be the FLUGELHORN? That would actually make sense. All of a sudden this
becomes no longer an oddity, but a way cool little unit. It fits the new RED
lineup: PICCOLO - FLUGELHORN - CORNET - TRUMPET. That gets the business
started. Excellent quality phono stuff. Then I add the HA-10, etc.
Dec 05
------
Got my TT stand spiked last night. Now I just need time to upgrade the arm
with my new VTAF and wiring. Anyway, got a RED PICCOLO built, tried out some
different caps. As soon as I get a RED CORNET or RED TRUMPET built I can do
some A/B with a stock unit to see if they are better or not. Still, running it
into a RIPPER phono was nice. Even with the cartridge not aligned quite right
the sound is more pleasant than digital. Can't wait to get one of the better
phonostages hooked up! I'll have much more stuff to listen to. Listening via
the HA-10 is an absolute joy.
Did carefully priced parts lists, HAGLABS style. I am trying out a new markup
formula, not the typical 3x thing. It is much more complex and I tried to take
into account a lot of variables. The idea is to get best dealer pricing
possible and still maintain profit and efficiency. No point underpricing a
product, as it just puts you out of business. A good example is the CASTANET!
Things ended up costing more than I expected. Look at the numbers. I sell a
kit/2 for $99. Then subract out the PCB ($31), hardware parts ($7), mailing
envelope ($1), and postage ($3). That leaves $57. That has to pay for the
roughly 20 minutes average order processing time and customer support. Or at
$50/hour (salary & benefits) about $17. Thus leaving $40 net. Now given that
I've been working on development since July, I estimate I have maybe 160 hours
into this machine. That's roughly $8k unpaid salary. And roughly $2k in part
and prototype expenditures. So to get ROI (return on investment) of $10k that
was already invested, it takes sales of 250 half-kits just to break even.
Yeah, that's how business works. I haven't even sold that many CORNET2 yet.
The key to profitability is the assembled unit. So don't think I am ripping
you off when I change the CASTANET pricing to $129 (that's my old 3x pricing
markup).
Meanwhile, I almost finished a RED VACUTRACE. Missing a few parts, so again I
have to wait. It looks beautiful. So much nicer than the old chassis. My
goal for December is to get this thing back on sale. That, plus the CASTANET.
Then in January I can do the HAGLABS website and start with an HA-10, CORNET,
TRUMPET, ARCHIVER, PICCOLO (all red). The CLARION (SE-10) was just a
distraction. No point to it considering the superiority of the PA-10 (yeah,
back from PP-10) architecture. Then I put PA-20 and DA-10 on back burner so I
can get some time on the PL-10, which is supposed to be the bread winner. The
PA-10 and PA-20 (4x6080) may end up being some of the best amps on the planet,
but I don't think I'll sell hardly any of them. They are just too advanced for
the marketplace. So it makes sense for me to delay the PA-20. The PA-10s I
need for myself and RMAF08.
And so I need a new photo for my website. Was thinking of something very
dramatic, like the bold side-lighted portraits you see of violinists and such.
Or one of those stark images in vanity fair or whatever. Well, I don't think I
quite got there. Here's my first try. An attempt at boldness, art, and at the
same time look intelligent, confident, reliable. I thought maybe the few days
of stubble would help (it does Mr. Pitt). Yeah, yeah, I know, don't quit my
day job.
Self portrait #1Self portrait #2
I finally got around to checking this online rag out. Not bad, very
interesting format. Seems like it builds itself in real-time, streaming ads
from a separate database. Sort of like google ads. After a very short time it
got extremely annoying, as one of the same damn four ads showed up every page.
Honestly, I couldn't even finish the issue.
Playbackmag
Dec 03
------
Haven't forgottent the PP-10. Still working on it. Tried out the cap to CT
yesterday. Bad move connecting it to middle node between cathodes, as that
really messed up the waveforms deep into clipping. Connect it straight to B+
was the answer. Clips wonderfully, just like no connection, but you get two
benefits. One, the low impedance forces extra drive into class A2 operation
for extra headroom, two you get an improvement in PSRR. It's a clever
connection I found in the WE 92A schematic. The idea I believe is that any
B+ ripple or wander gets fed to all triode grids. The plate, grid, and cathode
all see the same common mode shift, hence hiding the supply ripple. Thus, any
low frequency changes in line voltage (due to refrigerators, etc.) are somewhat
filtered out. The WE chose a high impedance connection, thus keeping operation
out of A2. I went low impedance, same as Lynn Olsen, to push harder into A2.
In the audio application, we want the extra peak power headroom. Today I might
try out the 6ep5 as a driver. Also, I'm going to find a way to put an LED in
series with the CCS on each tube, so you know if tube is operating properly or
not. A nice feature for something like the PP-20.
Oh my, I just saw this on asylum. Maybe I should make a product like this. A
wall of gear preset and ready to go. This is stunning!
My kind of tube amp
I measured a 6E5P tetrode strapped in triod mode. It makes a fine driver.
Almost as much gain as the 7788, but with more balls. I think I'll try it out
in the PP-10. Highly recommended by Romy. This has to be the best, most
linear indirectly heated triode I've ever seen.
6EP5 triode curves
Ok, so I wire up one of these tubes into the PP-10. This amp now looks like
frankenstein. This RF tube sits on wires. Is it gonna oscillate or smoke?
Fire it up. Hey, not bad! Whoah, holy moly. I'm getting way more signal
swing. Oh my, it is now pumping out 8 watts easily before it starts to clip,
and then it pushes well past clipping to deliver at least 12W. Sheesh, all
because I changed the driver tube? Ok, I did a re-bias and re-centering of the
stage. But still. It's pushing way more power into the output tubes. So I
hooked up the spectrum analyzer. Yup, harmonics all look the same. Distortion
down from 0.5% to 0.4%. This is it. This is the new driver tube for both
PP-10 and PP-20. In the PP-20 I'll use the 30H plate choke which will increase
the swing even more (mu = 2 on the 6080).
Finally did a first draft of a CASTANET parts list. Posted online.
CASTANET manual
Just hooked up the frankenstein PP-10 up to a speaker. Ran one channel out of
a CHIME GOLD. Oops, no volume control. No noise! I couldn't believe it. All
of the changes and playing around with that amp paid off. The noise floor was
virtually non-existent. Last time I listened it had a buzz and hum. Now
almost nothing. Sound was a little honky, but I don't know if that was because
it was only one channel, the speaker, or the amp. I hate not having both
channels. It always sounds like crap until the other channel kicks in. Maybe
if I had a mono source? Anyway, a good match for the CHIME now, as I get
nearly full power without clipping. I can safely say this will be loud enough
for my average sized room with the vandys.
Then I switched over to the CASTANET. Still can't believe the bass I get out
of these HD600s. Unreal. Did some A/B against a new pair of interconnects I
made. Very hard to distinguish between the two. Thought for a minute the
original Bolder's had better vocal presence, but my new ones seemed just a tad
louder or larger, I'm not sure. Can't say which is better. The good news is
that my new design wasn't awful. I'll make more and see what happens. They
are simple stranded coax silver over copper with teflon insulation. Military
overstock. Small diameter, gold RCAs with brass knuckles. Nothing fancy.
Dec 02
------
Shux, now I see that even the Lamm SE amp uses feedback. Crikey! That must
be how Mike at Quicksilver gets all of those great numbers. Shiese. It's like
racing against someone on EPO. I just ain't gonna do it folks. No way am I
gonna add that feedback. Another comparison is Lynn Olsen's Karna amp. 300B
PP delivering roughly the same power, but with more headroom into clipping.
same B+ power level. Probably lower distortion, but at the cost of 300B and 45
NOS pairs. Four 6080 is probably about $50. Or 1/10th the cost.
Raining like hell here. So I may as well get some more R&D in. Trying to see
what sort of chassis I can fit into. Thought perhaps putting the CASTANET
chassis on its side. Have two 6080 and one 5AR4 sticking out each side, the
6e5P out front. All tubes in horizontal position. Looks funky, but maybe not
practical. Then a flash of an idea, how about making the chassis extrusions
larger? Right now there is a silver stripe along each side of about 1/8"
height. It separates top and bottom cover. What if I replace these with
taller ones? I change the side panel from 1/8" to 1" or 2". Now front and
rear panels are much larger, say 6" x 9". Theoretically this would be cheaper
than two chassis with an umbilical. It gives me room to make a CASTANET
chassis fit all 7 tubes on top, the two power trannys on back. All on one
circuit board. The extra height means I can squeeze the output tranny inside
with a vertical orientation. It would look just like the other chassis,
expecially the new CORNET. Very compact and heavy. So I did a quick study of
costs, making custom extrusions. Entered rough dimensions into emachineshop
program. Whoah, it cam back over $60 a pop! No bargain. Maybe there is a way
to combine two existing ones? Might be able to use same trick to squeeze a
PL-10 from two boxes into one.
Extrusion example
Aye, I got it. The two extrusions side by side look funny, but if I add
another piece of black chassis in between, well then I get two silver stripes
and it looks perfectly normal. Funny, the extra aluminum panels they supply
almost fit perfectly. Just need to cut them down to size and paint. Or maybe
I could do a red anodized stripe? Gives me some easy options here to increase
chassis height. So obvious. And I can do any height. I could even convert
the new TRUMPET back to one box. Would be less work, but visually maybe not
as cool. For the phono stages, I like having two boxes, as it gives me big
spacing between power magnetics and input circuitry.
Dec 01
------
Spent all day doing yard work. So tonight (we didn't go out) I put my brain in
gear. Came up with a solution for the PP-20. Ok, maybe I should call it
something else, even though it is sort of a PP-10 on steroids. For years,
people have been asking me to do a high powered tube amp. Everyone wants one.
Probably would be my best selling kit. However, now that I am into the math, I
can't see any way to do this cheaply. Ok, there is the classic solution of
power pentodes and gobs of feedback. There is also OTL and gobs of feedback.
Oh my, it seems the ONLY way to crank out high power at low output impedance is
with feedback. Me can't do that. I design for sonics, not numbers. And so
that is how I ended up down the road of four 6080 in push/pull/parallel. With
all that tube and all that dissipation I can still only get out a modest 20W.
That will have to be enough. On the other hand, it will sound like way more,
and be refined and musical as hell. It won't have feedback.
Looking at available parts, I see my B+ current is rather high. Voltage is
very low at +250V, but current is 430mA or so. That's just more than what most
trannys and chokes will handle. So hey, do it in parallel! It has that
synergy thing since the output tubes are also paralleled. I chose a 273CZ
because it has the nice horizontal mount (like the other power trannys in the
HAGLABS lineup), delivers 325Vx2, has 5V at 3 amps for a rectifier, and 6.3V
at 5 amps, perfect for two power tubes! I'll have to add a small filament
tranny for the driver tube, which will probably be a 6E5P at 25mA. Anyway,
the trick here is to run two 273CZ power trannys, each with their own 5AR4
rectifier and 159S 4H choke into 800uF (or maybe 1mF) capacitance. This gives
almost a perfect 250V output at 430mA. Only 0.15Vrms ripple. I'm hoping that
is good enough for PP operation with no hum, given some tube mismatch. If not,
I add another pair of 4H chokes and another bank of big caps. Hey, 8 of those
100uF panasonic EB caps in parallel gives you some pretty low ESR and ESL.
The driver will be CCS SE into the interstage tranny / phase splitter. Four
output tubes means eight triodes, each with their own 50mA CCS. The choice for
output tranny is the 1650H driven by the UL taps. That's 264 ohms per side. I
might get a little less than 20W output now, but impedance with be close to 2
ohms. Hmmm, this is almost a cross between a CYMBAL and a PP-10. Low voltage,
high current operation. Very low turns ratio (only 6:1!). I think it will add
up to some superb performance. Wow, that's only 6 chunks of big iron. Now to
find a chassis. Alternately, I could run a pair of 6C33 in exactly the same
design?
Just realized that driving via UL taps will bring the primary inductance waaaay
down, potentially destroying the LF performance. I might have to buy one of
these trannys and experiment. The Hafler will come in handy again.
No wonder everyone uses feedback.
If I lay all the parts in a line, I get a narrow 10" wide chassis. By 24" to
30" long! This amp would be a good candidate for hand-wiring, except for the
CCS. Hey, maybe I need to make me a CCS module? I suppose I could jam this
onto an 10 x 17 chassis. One monoblock. Re-did the math for the 1650H, looks
like about 15W into 8 ohms. A giant SS amp can deliver 200W with 40Vrms. I
got 14Vrms (40Vpp) at 2 ohms, or about 1/3 the output voltage. Is that enough?
That's all I can get out of a proper design. It'll sound like 50W, though.
Aha! I goofed. Forgot that I only calculated 1/2 the output stage for
impedance. So in reality I should be getting 1.1 ohm out. Whoah, that's
pretty decent. This bumps power up to 19W prior to clipping. Ok, so let's
call it 20W. And PP-20 is now a very good name. But is this right? I checked
out a really (awesomely) good commercial amp, the Lamm ML1.1. It's a beauty,
and the measurements show it. Very close to what I am doing, but with one
difference. My idle is 225W (from ac line), the ML1.1 is 200W. Both have Ro
of about 1 ohm. Mine cranks out 20W, the ML1.1 80W. What!? Yep, it has to
be feedback. This is indicated in the square wave stability test loaded with
2uF in parallel with 8 ohms. Such would cause an RC bandwidth rolloff in my
amp, but with feedback you get peaking. Only feedback can do this! Also,
looking at the distortion vs. power graphs you see a discontinuity and abrupt
jump at clipping. Mine will be a curve similar to the CYMBAL, gently rising
upwards as power increases. Ok, so maybe my amp will sound like 80W?
CYMBAL distortion
Nov 30
------
And so I realize last night that the PP-10 architecture can be extended to much
higher power. Yeah, the article in TAS mentioning the Magnepans need gobs of
power. What to do? Ok, so 20Vrms into 8 ohms is 50W. That should be enough?
That's 30Vp, and normally I get 100Vp out of a 2A3 or 6H30. That leads me to a
tranny ratio of 4:1. Not very much. 128 ohms on primary? What is going to
drive that? I realize all high powered tube amps run boatloads of feedback. I
can't do that. That means tubes with a lot more voltage swing and/or lower
output impedance. All I can think of is the 6C33. Is that why everyone uses
it? Not the most linear of tubes, but many claim it sounds great. Superb
construction. What else could I use? A 6080? 6C19? I need to think about
this. Could be a great project once I get the TEN series out the door. The
good news is that the PP-10 topology works with many tubes in parallel. I
imagine a big chassis with maybe 10 output triodes. If they were 6080 or
similar dual type then a tube could be pulled safely while still operating.
Only the power level would go down. It would still work.
Ok, did a quick study here. Using a 6080 dual triode, they run low voltage and
have ~300 ohm output. If we take a 5k output tranny and use the ultralinear
taps, they're at 40%, or 0.4. That's then a 5:1 turns ratio (0.16 * 5k), or
200 ohms on each side. Thus, to have 4 ohm output drive on 8 ohm tap we need
100 ohms plate, or three 6080 in parallel. One 7788 should be able to drive
all three tubes no problem. At low voltage we use plate choke instead of CCS.
I love it. All iron! About 400mA B+ at 150V. Lots of heater current. We
can only get about 100Vp output from tubes, so that gives roughly 15Vrms at
output. A 3.5dB power loss (4 ohms into 8) means we have 10Vrms into 8 ohms
for barely 12W output power. Hmmm. This is a LOT of work for not a whole
lotta power. With 6 tubes in parallel we get 2 ohms out, and 18 watts. The
tubes are damn cheap! Hmmm. If I squeeze 120Vp out of these tubes, then six
in parallel get 23W. Ok, so we clip at 25W, pushing the design. That's with a
lot of output tubes. About 50Vpp into 8 ohms. Right now I get 20Vpp with the
2A3s in the PP-10. Yeah, this is worth looking at.
Did some compromise, in order to make this reasonable and a practical
implementation (real world parts). Four 6080 output tubes, rebiased to 170V at
-80V and 50mA, can deliver 20W into 8 ohms. It does not stay in class A when
delivering the large peaks. That's 50Vpp output. 100W of B+. 70W of heater.
Seven chunks of heavy iron. Nine CCS. No biasing necessary. Zero feedback.
Nov 28
------
Well, I've stopped about 75% of my email spam, just by dropping the *.hagtech
mailbox. Not sure if I am still under control of worm/virus yet. I think my
firewall is helping.
More cool amplifier tests. I connected headphones straight to the output.
This is a great way to hear the noise and microphonics. It has some buzz and
hum. We knew that. But it was nice to hear no change between R = 10 and open.
The 7788 has a very unusual "ping" to it. Not the normal microphonic ping or
thump you get from a preamp tube. More of a long lasting shimmer. The tube
dampers didn't seem to help. I guess this is due to frame-grid construction?
Anyway, I then hooked up my Hafler power amp as a driver stage, bypassing the
7788. It drove the interstage tranny. As expected, the 2nd harmonic went way
down. In fact, by 14dB, enough to cut distortion by 5x.
PP-10 distortion using Hafler driver
This is looking all wrong, though. You want the harmonics in a nice decending
fashion. Here the 2nd is on par with 3rd (and with R = 100 it is), which does
not lead to good sound. Again, I see the exact same 6dB change in 3rd between
R = 10 and R = 100. And the spurs on the fundamental rising at R = 10. Still
wonder about those spurs. Is it the 2nd from the driver mixing with the 2nd
from the output? What makes the 3rd come up so much? Why is no 4th visible?
Nov 27
------
Some more PP-10 testing. Seems the trends don't vary much with signal level.
I am still getting a 6dB increase in 3rd harmonic at R > 100 versus R < 10.
Did discover that my wein bridge light bulb oscillator has a bit of 5th
harmonic built-in. Changed to the EMU-0404 output dac as a source. Now all I
can see are 1st, 2nd, 3rd. Nothing else shows up. I can't run the power level
too high or it clips the ADC input. Maybe I should build a resistor pad. So
at about 4Vpp output I have roughly 0.5% distortion.
PP-10 distortion spectrum at 1kHz
It took me awhile to figure out the best operating conditions for the FFT
software. Always had it set to maximum 65k sample points. Hey, go for the hi-
res, right? Nah, you can't see anything but spikes. The above plot is with
only 4k points! Doing so is like adjusting the bandpass filter. This setting
is good for 1kHz sinewaves. I also ended up using the blackmann-harris window.
It seemed to give the most useful information. Most significantly, I can now
see 60Hz or 120Hz spurs riding on the fundamental! I am getting some mixing
going on here (multiplication). That would be IMD? At R > 100 the spurs drop
way down, but the 3rd comes up. I suppose that just means I am losing some of
the inherent power supply rejection of the differential stage. Maybe that is
where the compromise comes in? I dunno yet, but my first impression is to drop
the 3rd. Might have to do A/B listen.
Ok, so I tried to make a distortion versus frequency plot. Changed FFT to 65k
for all readings.
PP-10 distortion vs. frequency
It remains solidly at half-percent across the band, then rising a bit in the
treble. I was suprised it was so good in the bass region. Usually this is
where things start to fall apart. Ok, so now distortion versus power.
PP-10 distortion vs. power
Looks like about 0.1% minimum distortion before the noise floor kicks in (which
I'm sure I can make quieter). Then we get a hair over 1% at 1W. That's not
bad, but I think I can do better. Wonder how much of this is driver stage.
Maybe I need to make me a scope probe buffer/attenuator? That way I can
measure distortion at any point in the circuit.
Maybe I need that 1uF from between the cathode caps back to the CT of the grid
driver tranny? Need an input loop retun path for paralle mode. Don't think I
can jam it into this frankenstein of a circuit. Too many changes already.
Also realized I don't have the electrolytics bypassed. One thing of note, the
power level on that 100 ohm resistor is really low. I was getting about 1mA
through it. Very low power dissipation. Theory has it that only the imbalance
signal passes throught it, balanced are cancelled. So that would mean I have
perhaps a 2% imbalance between my 2A3? That's a really good match. Seems I
need to do a relayout here and try out this massive batch of changes before I
can tweak more on distortion.
Ok, so I made me a probe buffer out of a BUGLE board. A 1M resistor and 5pF
added gave almost a perfect probe calibration (preset to match my Tek 7704).
The 0dB buffer then feeds the EMU-0404 ADC. The 10x probe allows me to then
look at large signal swings. Oops, forgot to ac couple it. Anyway, looking at
the grid drive I get almost the same level of distortion. Perhaps this just
means most of the 2nd order stuff is from driver, not output stage. Hey, I
suppose this ain't too bad, 50Vpp at 0.5% with no feedback through a tranny.
PP-10 driver distortion
Hmmm. I wonder if the driver stage is part of the harmonic balancer solution.
Nov 26
------
Finally done with all of my painting and house repairs! The 5-color scheme was
more than enough work. I must have gone through a mile and a half of masking
tape. Here's a shot looking through the kitchen. You can see the cranberry
entry at far end, the orange swoop of a soffit that passes through three rooms,
the green, the moccasin (tan), and the white trim.
House paint
Spent all day with production. Nothing else to report on. Oh wait, this just
in. Rigged up the PP-10 for distortion tests with the PC. I wanted to map out
the changes as the harmonic balancer resistor value was varied. Except when I
set it to zero the CCS blew. Sheet. Took me an hour or two to straighten that
out with new parts (didn't have any more TIP50 on hand). My guess is that I
gave it a transient by slipping with an alligator clip. Anyway, after that was
sorted out I had my full power back and low distortion. But things just
weren't changing as they should. Here's what I got at about 1 watt:
R % 2nd 3rd
---- ---- ---- ----
10 0.49 -49 -75
220 0.51 -49 -69
330 0.51 -69
1k 0.52 -68
220k 0.53 -48 -67
The overall distortion was dominated by 2nd harmonic at roughly 1/2 percent. I
am wondering if it is all due to the driver stage? The deal here is, in fully
differential mode (220k), the output stage should cancel all even orders. It
gave me a 1dB change. In the wrong direction! In parallel single-ended mode
(10 ohms) it gave a 6dB drop in the 3rd. There wasn't much of anything else on
the screen. Would have saved a jpg but my battery ran out. Does this make
sense? I was supposed to find a null somewhere in the middle. Or so that was
my theory. Should have been around 250 ohms. Hmmm. Maybe I should test at
higher or lower power. The WE92 schematic has a resistor value of 85 ohms. Or
maybe it was 65 ohms, I can't make it out. That was with 300A tubes, so I
figured maybe double to 120, which was my original design value. What is
missing is the 1uF to grid tranny center tap. Me thought that was just for
ripple rejection. Maybe all the magic happens between zero and 100 ohms.
Nov 24
------
Have to keep on schedule here. So many projects, must keep the goal of RMAF08
in sight. Mostly, I have to have a PL-10 up and running by that time. That is
by far the most difficult and time consuming design. These other ones are
mostly slam dunk. Yeah, I put a lot of time into the HA-10 and PP-10 so far.
The others build on that work. For example, I came up with a new design for
DA-10 based on the B+ supply of HA-10, the CCS and driver stage of PP-10, and
the filament supply from PL-10. Only I had to change a few things. My trick
this time is to power the filaments separately. Left channel on +6.3V and
right channel on -6.3V. And to be a TEN series means any rectification has to
be done with choke filter. Ay ay ay, that is so hard for filaments. In this
case I make +/-6.3V supplies for filaments and HAGDAC. However, it is not
straightforward and the values are awkward, such as only 0.5A current per leg.
The problem is available chokes. That will fit. Again I end up using the 155B
0.006H choke, but two in series for 12mH. Two per side means 4 chokes just for
heaters! Also using a split transformer to maintain layout symmetry (and stray
field cancellation). I end up with 6 pieces of iron just for heaters. And the
means 9 total, just for a tube DAC. Probably $140 wrapped up in 9 chunks of
iron, giving a world-class power supply. I think I came up with an arrangement
where the HAGDAC fits in the middle, a 7788 on ech side for output. Leave off
the fancy controls and IR. Maybe a couple of LEDs, one for USB, one for lock.
Plug and play. No knobs or buttons. Make it as simple as I can.
Ok, so now I have: HA10 - TRUMPET - CORNET - ARCHIVER - PICCOLO - PP10 - DA10,
all to be completed and shipping before I even start the PL10. That should
leave me maybe 5 months to do the proto. Maybe this is too big of a bite to
chew. The idea is to get the simple stuff out the door first, set up a base
upon which to build. Get some revenue flowing. Meanwhile I still have to get
this new VACUTRACE done. That should be easy, as it's just a matter of
soldering what I already have together. I have to put the CLARION / SE10 on
hold for now, make sure I can get this other stuff done first, while still
keeping up with current production.
Nov 23
------
Hooked up a real CHIME last night to play for the CASTANET. Well, once again I
am floored at the differences. The RIPPER was fine, but by comparison is
really in-your-face. The CHIME was soooo relaxed and smooth. But that's not
suprising. What really hit me was the bass! Oh my. Thunderous bottom end.
It's like the entire EQ was shifted. The top end almost seemed rolled off
(back to my original impression of the HD600) because the bass was so huge.
Whoah, this I can live with.
My 156 came in. That's the interstage tranny alternative to the 124B used in
the PP-10 (formerly PA-10). A quick run of bench testing gave it a similar
27kHz self resonance. Bandwidth, even damped, went up to 50k or so. I forget
exaclty what the 124B did out of circuit. Anyway, I'll give it a shot. Seems
to me nothing will change. Also got the new filament trannys.
Staring at the TRUMPET and PICCOLO red chassis. That yellow lettering just
isn't doing it for me. The wife still says it looks ok. White would be ok.
The issue isn't really the black covers (which are way better than the beige),
but the aluminum strip down the sides. I have exposed metallic silver color
highlights all over the chassis. Extruded aluminum and stainless steel. So
why not make silver the accent? Maybe the engrave lettering doesn't need any
ink at all? Silver-red-black. That's not bad. And I'm backing up a little,
thinking maybe I should offer a more traditional option. Since these machines
are likely built to order, I may as well offer a choice in color. But only
two. The silver (clear anodize) faceplate of that ARCHER I built was
beautiful. It would work here. Silver face, stripe, black covers. Very
classy and traditional. So I would have choices of either red or silver.
I still need to order panels for the new CORNET and the new ARCHIVER, so heck,
it's a perfect opportunity to try out the new styles. Eventually, I will
converge on a solution. That's just the way R&D is for me. Go in circles,
make a lot of mistakes. Fix it now while you can.
Nov 22
------
I am now set up to take pre-orders for the CASTANET half-kit. Posted schematic
online (final version). I noticed that the color of the LEDs on the proto
looked incredible in a dim room. I think the 2mA or 3mA I run them at is just
right. A deep amber color, not too far off from the glow of the 6H30.
CASTANET schematic
Had me a bit of a scare yesterday. Was listening to the CASTANET in the lab
hooked up to my modified cd25. Playing an old REM CD (I like some of the
songs). Anyway, I noticed I had to keep turning the volume down. Oh crap. I
could listen loud only for a short while. By the end of the CD my ears were
hurting. Oh crap. Is this right? The sound is vibrant and punchy, why am I
getting fatigued? There must be an edginess or harshness! Oh crap. Did not
post this finding to the blog.
And so last night I brought the CASTANET inside and hooked it up to a RIPPER
used as a USB DAC. All I had at the moment. Played an MP3. Ugh. It was
awful. I could hear every last detail of imperfection. Every encoding
disruption was blatantly apparent. Gads. Then started to play my usual test
tracks. Hey, not bad. What a big difference going from MP3 to FLAC. All of a
sudden it was music. Hey, this is pretty good! This is coming from a RIPPER?
Most significantly, I found myself cranking it up. There was no more ear bleed.
In fact, I could pound my ears with ungodly SPL (anyone who listens at full
volume is mental). No harshness. No fatigue. Any volume worked just fine.
Full, beautiful tonality and pace. Very neutral and uncolored. You can't get
this from speakers. I now understand the head-fi crowd. Easy to hear
everything on the track. The resolution was brutal. Nothing gets hidden or
smoothed out. No sweetness added. Clearly, the CASTANET is revealing. If
there is any flaw in the recording, it will be apparent. Sorry to say, bad
recordings are not made more musical with this amplifier. If anything, the
flaws are exposed. I was sort of hoping the CASTANET would make marginal
recordings more listenable. Sad to say that is not the case. One last
interesting point. It was late, I'm slumped in a comfy chair. The tunes are
blasting in my head yet I could fall asleep. How is that possible? Tonight I
try a CHIME instead of the RIPPER.
Now I wonder if my cd25 sux or was it just that REM CD.
Nov 21
------
Ugh, fighting some sort of email virus. Shoot, seems hagtech.com is now
spitting out a new spam every 20 seconds or so. Something about a canadian
pharmacy, I think. Been trying to clean things up, see if I can stop it.
Meanwhile, limiting my email addresses to "jim" only. Used to be anything@
hagtech.com would get to me. I had LOTS of spam. Now, maybe I won't. Got the
firewall kicked in to higher levels, etc. My guess is the problem is related
to some disney interactive online game the kids were playing. It's not puzzle
pirates. This computer is slowly dying. Hard drive don't always boot, it has
years of crap all through the registry, which was also completely screwed by
registry mechanic. Everything is hanging on by a thread. Any day now it might
lock up permanently. Fortunately, all data is backed up in several places.
Here's a shot of the new red TRUMPET. I'm no longer enamored with the yellow
lettering. In fact, I wonder about no ink at all. Just engraving, bare
aluminum. I have aluminum and stainless steel hardware accents all over, so
maybe it would be a more natural look. Fewer colors. The black painted
chassis covers changed everything visually. I guess I need to experiment a
little more until I find the most promising combinations.
Red TRUMPET proto
The power supply box is incredibly heavy. Very solid feel. The rubber feet I
chose are working great, much better grip and cushioning than the typical vinyl
bumper. However, there is a vibration in the amplifier. When I bounce it
there is a rattle. I think the circuit board within the chassis rails? If I
press on the board the rattle goes away. So I need to come up with something.
My first thought is to run a nylon standoff from the centers of the tube
sockets down to the bottom cover. The #4 nuts are already in place. Would
this be a good connection or bad? Might be a solution for othe chassis with
rattles and shipping damage considerations. I guess I can live with a few
screw heads in the bottom cover. Mechanical integrity and vibration control is
far more important. Meanwhile, the CASTANET box seems just fine with the
bumpers inside. No rattle.
Nov 20
------
Finished building the CASTANET. Worked out all issues, just need to implement
them into the layout. Suprisingly, the numbers came out really good. Must
have been due to the component and circuit changes. I realized that 20Hz boost
of 2dB we had before might have been caused by the power supply. Yeah, the
supply impedance (Ls and Cs) were ringing in opposition to the signal giving an
artificial boost in level. Well, I had doubled the B+ capacitance, and yup,
now the +2dB is at 12Hz, but only with the outputs unloaded. I don't need
those extra 100 ohm damping resistors then, as I can live with this. On the
Grados there is no boost. The Sennheiser bandwidth is thus 8Hz to 355kHz, and
Grado from 12Hz to 267kHz. That's much wider than it was before. Output
impedance is still 9 ohms (LO). Noise and hum went way down. Broadband was
0.4mVrms. A-weighted it shot down to 12uV, or -98dB referred to 1V output.
I'm happy with that. Forgot to measure gain and distortion. Will do that
after it burns in for a few hours.
CASTANET proto frontCASTANET proto back
Worked out a few minor issues. Like how to add mechanical support in center of
board. It can get too much droop. My first thought was to use nylon standoffs
connected to bottom cover. But when measuring the gap, I realized the space
from tops of trannys & chokes to cover was almost exactly 1/8". Doh! I have
all these 1/8" rubber bumpers. Bingo. Just put a bumper on the top of each
tranny. It worked perfect. I get the extra structural robustness needed to
survive shipping, plus it has inherent self-damping. And I don't have to drill
holes in the cover. Also, the alternate headphone jack I selected needed a
thicker panel. Must stick with other version. Sure glad I found this out now!
Oops, I took the earlier bandwidth measurements improperly loaded. I ran it
open and with Grados. Well shux, they must not stay at 32 ohms in the ultra-
sonic region. Ok, so let's do this again at 32 ohm load. Actually, I ran a
64 ohm load on the HI output (same as 32 ohm on LO). Ok, now things look
normal. True BW is 12Hz to about 75kHz. Distortion mainly 2nd order being
0.4% at 300mV output. Gain is 2.6dB. Maximum output level is 4.0Vrms, or you
could say 3Vrms maximum input prior to clipping (which is really soft and
benign). Here is the square wave response. That's awfully clean for a tube
amp and no feedback. No squiggles or ringing.
CASTANET at 10kHz
Wow, this really proves the "sum of its parts" theory. The CASTANET sings.
Way better than it should. Good topology and holistic synergy go a long way
towards making a great design. And this machine has it. This is world-class
performance, and I did it using commercial-grade transformers, chokes, and
caps. Ok, the 3.3uF films are $10 a pop, but they aren't your V-caps or any
other uberphile part. It's not about how many over-the-top parts you can stuff
into a design, it's about how you can get them to play together. And in this
case, the whole is indeed far greater than the sum of the parts.
Nov 19
------
Oh my, I did a quick look at the mechanicals, and suprise! The CLARION circuit
will indeed fit on the HAGLABS chassis. I had figured there was no way enough
room. Guess my original 11x17 layout was pretty sparse. Pretty tight, and it
will weigh a ton, but having the power tranny hang off the back is what did the
trick. Ok, so now we have PP-10 and SE-10, the latter also to be offered as a
CLARION half-kit board. I have some changes to make. Perhaps do a CCS on the
driver? All the iron and tubes are the same.
I got most of these TRUMPET pieces sort of together. And I just am not liking
that yellow. Maybe I don't have cojones? To me, the white looks much more
natural. Something fluorescent in the combination yellow/red. Must rethink
this. The VACUTRACE looks wierd too. The HAGTECH machines will definately go
white. It's the HAGLABS units that I fret over. Big difference once I put the
glossy black covers in place.
Ok, CASTANET fired up ok. Sounds wonderful right out of the box. Must do
final tweaks, but so far everything looks spot on. Every dc voltage is within
a volt. And this is even after trying out a new tube. I marvel at how much
sound this thing can put out. And only the one tube. Hum is all gone. My
tricks worked. Painted the covers almond again. But now I'm wondering if the
CASTANET panels should just be au natural. More contrast with the knob. HA-10
of course, will be red. The big CD caps are working out. Also did a re-wiring
of the primary back to cathode rather than ground. Will do measurement and
listening comparisons tomorrow. I think I am close enough to just do the last
few changes for production, then get the boards ordered this week. Yeah, I
work on a lot of holidays. That means I should have boards by 12/10.
CASTANET proto #2
Nov 18
------
I woke up in the middle of the night, thinking hey, why not put the PA-10 power
transformer on the back panel, just like the new CORNET? Well duh. A genius
would have figured this out up front. It took me several months. Looked into
it and seems to be a very good fit. This will save me a lot of time messing
with the top covers. And, the amp might look nicer without a visible tranny.
Nothing but tubes. I needed to make some other changes inside, like rotate the
output tranny 90 degress, move things around a bit. Plus a ton of changes I've
worked out over the past few weeks. Also think maybe I change the name to
PP-10, which means push pull instead of power amp. That way I can later add a
SE-10 if I feel like it. Would LOVE to put a CLARION circuit into one of these
chassis, except I don't think there is enough room.
Oh, I also painted the CASTANET covers black. Shoot! I was supposed to NOT do
that. This was supposed to be an example of a DIY-built machine. Oh well.
Maybe I find me some beige paint and paint it back the way it was. Ugh.
Nov 16
------
Yesterday I did the paint job on the new TRUMPET chassis. Whoah! When I
checked on them this morning, I was stunned at how beautiful they came out.
What was once a drab beige hammertone (textured) finish is transformed. The
glossy black paint over the texture is gorgeous! I can't believe what a
difference this makes. It went from a piece of test equipment into a hi-end
shiny chassis overnight. This is such a relief! Now, if I can only find some
time to get me a real compressor and paint gun.
Discovered that painting is a bit of an art. Realized I didn't get enough
color on the edges, went back and touched them up. Well, duh, it seems that
this screwed up the nice even gloss across the top. Waited a few hours, nope,
didn't go away. At a certain distance the spray is a little too fine and
sparse, not covering properly. Seems you need to saturate the entire area with
a wet coat in order for it to dry with even patterned gloss. Ok, so I threw on
another coat.
Last night I spent 3 hours in a flurry of part ordering. Six different
companies, had all websites on at once, so if mouser was out of stock, I would
find something at digikey, etc. Agonizing to try and keep it all straight.
Anyway, after I was all done and hit the six submit buttons, I realized I
forgot to order more HAGUSB boxes. Crap! Oh well. I have enough to last
another week.
Nov 15
------
Thinking maybe one of those LED light pipes might work well for the IR remote
control receiver window. Better make sure it can pass such a long wavelength,
though. Forgot this window needs to match up visually with the rest of the
decor. Focusing hard on WAF. Yup, that's going to be one of my key selling
points. Wife Acceptance Factor. Small, cute, unobtrusive components. Stuff
that doesn't take up the whole room. Stack them nicely, if you want. If you
bring your wife to the store, she'll say, "that one is fine." Something in me
rebels against the gigantic sculptures that some companies put out. Unwieldly
contraptions that all compete for the top shelf. Which is where the damn
turntable is supposed to be!
Ok, tried some series damping on the PA-10 interstage. Ended up with pretty
much the same result, but more gain. Oddly, discovered the tranny is not
symmetrical in it's HF performance, as one secondary loaded with 22k does all
the work, 22k in the other has minimal impact. So somthing is up with this
tranny. Is my sample ok? Are the secondaries wound bifilar? Seems perhaps
not. Regardless, when I have it tuned in for maximal performance, the
waveforms look perfect, just bandlimited to 23kHz. I'll have to listen some
more to see if the treble is impacted. Loss of air? Meanwhile, I order the
156 interstage tranny tonight. Can try it next week. Once I get that nailed
down I can do the harmonic cancellation testing.
One more HAGDAC to build and then I can get back to finishing up the HA-10
proto. More stuff in paint shop. Oh yeah, built me a new wooden shelf last
night for LP storage.
Trying to figure out where to put an LED on the fron of the red CORNET.
Nov 13
------
And now I discover my inventory is perilously close to running out of BUGLEs
and POWER SUPPLYs. Oh my, more stuff to order.
Getting some chassis parts ready for painting this afternoon, but figured I
better drill the footer holes first. Need template. Hey how about this CORNET
board? Just off a little bit, so I use something else. Hmmm, isn't it
interesting how the CORNET classic board fits perfectly inside the new red
TRUMPET chassis? Doh! Then it hits me. Shoot, this is an easy one. I
realize the tranny can be mounted to rear panel, everything fits. Wow, this
would make for an even smaller CORNET. And so it was born. Why not? I can
offer the RED CORNET in the upgraded chassis with upgraded caps and stuff from
HAGLABS. Too bad I can't come up with this stuff myself, it has to happen by
accident. Sort of makes the HAGLABS launch a bit more phono-centric. Should
have me the RED ARCHIVER, RED TRUMPET, RED CORNET, and RED PICCOLO. Plus the
HA-10. The LC-10 and PA-10 will come later, although they both have working
prototypes at the moment. I decided to keep the VACUTRACE, FRYBABY, and UFO
with HAGTECH.
Meanwhile I am so busy just filling orders, I can't believe I get anything else
done. It takes me the first 5-6 hours each day to keep up with production.
After that I move one to the new designs.
Discovered during that 7788 triode curve test that the VACUTRACE uses too much
plate voltage modulation for measuring gp. I'm going to look into reducing it
to 25V. The line on the scope gets a little bent, leading to a slight error.
Ok, back to working this PA-10 board. Changed the driver tranny primary
connection to cathode. Hey, might as well do as much as I can from the 92A
schematic. It's a good topology. I also got to look at the effects of the
soft ground connection to the driver center tap. This is very unusual. It
lets the common mode float. What happens is that in grid current saturation,
the coil gain compensates by pushing the other grid harder. Funny looking
waveforms in saturation, but the result is symmetrical clipping. Overdriving
this amplifier is not a bad thing. It handles it really well and in a very
nice fashion. Soft clipping with no harshness. I still have to add in the
1uF cap to cathodes, see what that does (I think a clever way to add power
supply rejection). Then I have this idea for positive feedback neutralization,
using the 40% taps coupled through 10pF micas back to opposite grid. In theory
this can greatly reduce the input capacitance. The problem for me, is that my
bandwidth limitation is all with that nickel core interstage tranny. Or is it?
I have yet to try series damping instead of parallel. Also can try the 156
interstage tranny, which is on order with the L2 filament trannys (have to find
the better balanced). Oh yeah, and then the harmonic cancellation. I'd also
like to do listening tests on each version as I progress. Last night I rebuilt
my speaker cables. Ripped them up and converter to a simple twisted pair
teflon over silver. Mostly I just wanted to remove that plastic jacket braid.
Sure, it looked nice, but that's not exactly what I want as a dielectric.
Finally, I am having to raise prices a little. This fall in the dollar has
really started to add up. My parts costs are up at least 25% across the board
over a couple years ago. Especially with items like the PCM1704, I'm now
paying double what I used to.
Nov 12
------
Got me a better sample of 7788. New curves look like this. I now get 1.5k ohm
output impedance, which hits spec.
Improved 7788 curves
Thinking I'm not going to move VACUTRACE over the HAGLABS. Maybe such would
cause confusion. I should not have any direct sales at that website. My
desire to launch with lots of product made me do it. After a weekend of house
painting, I can think more clearly. KISS. Just launch the TRUMPET and HA-10
stuff to start. The VACUTRACE does not need to be red. Forgot to order
ARCHIVER panels. Oops. And now I am running out of BUGLE and POWER SUPPLY
boards. So much to reorder! Sales are good, with a big increase in assembled
machines (HAGUSB, PICCOLO, BUGLE).
Meanwhile, building up my new listening room. Bought this $160 cutting board
cart for conversion into a TT stand. Very thick hardwood, has really inert
sounding quality. Much better than my other racks. No, I don't have a sandbox
or anything fancy. I left off the drawer and a middle shelf, only bolted
together what was needed, added glue to the mix. Once I cone it, should be a
pretty decent, heavy, and inert platform. Someday I can put a Serac or similar
on it.
Nov 10
------
Sat down and did some thinking last night. Try to plan my next moves on this
PA-10. So far, it's actually moving along quite well. I have a complete
working amp that sounds decent. Me want more. So I'm going to try some
alternate parts. The 124B is causing me the bandwidth limitations. So maybe
I try one of the other versions of this coil to see if they work better. Was
hoping this would be a good piece, due to it's high nickle core content. Will
also try the L2 heater trannys. I used them in the CLARION without any hum
imbalance. Maybe they will work better than the M2 style. I'll pay the extra
$5 if they do.
Interesting item, I accidentally discovered that the circuit operated just fine
one one tube. At about 1/2 the output power. Output tranny was singing like a
bird, though. One thing I didn't check was how well the common mode balance
correction works. That's the series 47k with the center tap on secondaries.
Normally this would just get connected to ground. However, I believe there is
a certain benefit to not doing such. You see, when driving into clipping, one
grid enters into positive grid current. When this happens, the common mode of
the driver coil shifts to put more signal on the opposite tube. Somewhat of a
self-compensation. Forgot to look more carefilly at this mode of operation,
however, I did notice the drive waveform does not saturate and clip like the
output does. Maybe it is working. I will try it both ways. You see, I am
drawing inspiration from the WE92A amplifier of 1935 and comments by Lynn
Olsen. This extra resistor is found there. Also the unusual harmonic balancer
mode of operation. My topology is similar, but with the additional advantage
of CCS loading, and capacitively coupled cathodes, allowing for unmatched tubes
to accomplish the same thing. Sort of taking it to the next level.
Lynn's comments on WE
Nov 09
------
Got a lot of panels in. The CASTANET (DIY version) and TRUMPET. Hmmm, they
both have fit issues. I did not leave enough room for the insulating washer on
the RCA jacks. Slight interference in both machines. Also thinking I want to
add a standoff from board to bottom chassis panel in order to help with the
heavy tranny weights during shipping. Holding the boards along the sides may
not be enough, looks like there is a little droop. Drop the box and board
could crack? A nylon standoff should do the trick, stay insulated, yet still
offer a little vibration damping softness. I find nylon works great for such
microphonics control. Perfect as washers under the chokes, too. I have same
problem with PA-10. Too much board droop.
Some thinking on the 7788 curves. Why are they off? Then it hit me, there is
a little bit of cathode degeneration in the VACUTRACE. Not an issue with most
tubes, but it shows up with this uber-tube (high mu, low rp). Doh! So I have
an idea to reduce the degeneration and make up for it with more gain in the
processing stages. Will try it out. Perhaps I can get more correct curves to
match the data sheet. Right now it shows the rp too high.
More work on the PA-10. My first try to reduce the noise was putting the bells
back on the output tranny. It's a good idea regardless, and they fit, even
inside the chassis. But that didn't remove the hum! Shoot. It is 60Hz, not
120Hz. After a lot of playing, finally discovered that the heater trannys are
not balanced perfectly. They both measured about 1.237Vac and 1.221Vac
relative to center tap. Crap! I'm feeding the 60Hz signal right into the
tubes. Aha, but I noticed they are connected to the primary side with the
same polarity. So I switched on, thus cancelling the effect in the output
stage. Son of a gun, it worked. That 16mV differential noise on cathode was
multiplied by a mu of 4, divided by a turns ratio of 12. It measured 8mV on
the 8 ohm tap. Now it is under 2mV. Hooked up to the vandy again and could
not hear it. Just a faint buzz. Putting on my A-weighted meter, I now have
85dBA SNR ref 1W. That's actually pretty friggin good. Great! I didn't have
this trouble with the trannys I used on the CLARION. It shows up with the
166M2. Hmmm, maybe that's why it is cheaper?
So now work on bandwidth. The driver stage is flat out to who knows what. At
250kHz it hadn't done down a hair. Everything is lost in the interstage
tranny. That makes sense, as the CYMBAL pushed 95kHz through the output
tranny. Yep, it all comes down to the 124B. I have no dc on it (parafeed), so
there is not much else I can do. Driving it hard with a 1.5k ohm output from
the 7788. The 2A3 grid capacitance ain't that bad. Yeah, it just falls off,
with some ringing and glitchies to boot. So I tuned the secondary loading,
found out that 22k ohms per side gave a PERFECTLY tuned square wave response.
Absolutely beautiful waveform (at 8 ohm tap). It just happens to be at half
the bandwidth I desire. Perfectly behaved rolloff, but the -3dB point is at
22kHz. Well, that's perfect for CDs, anyway. A little soft for vinyl. My
ears probably couldn't tell the difference. Sensitivity dropped to 0.6Vrms
for full power. I should try series damping. That might bring BW back up. If
its a resonance with grid capacitance, anyway.
Oh yeah, also redesigned the current sinks for the 2A3. Back to a 12V zener
circuit, one without feedback (which I think is important). Still have to
work out the right value for harmonic cancellation. Thinking that resistor
needs to be 250 ohms. My earlier guess was 120. I'll measure the spectrums at
1W for several cases. It should lead me to a null. If it works per theory,
well then I am stuck with the interstage tranny, because this way cool topology
needs it. Relayout will be a bitch. So much changes.
Anyway, the weekend is here and I gotta get back to painting the house.
Nov 08
------
Finally got me a backup of my CNC files on floppy. That lab PC crashes and
dies about once a year. I'm on my 4th machine now, I think. Anyway, the files
are of G-code programs that tell the CNC machine how to move and cut. That
logo stencil I did last week looks like this.
HAGLABS logo machine code
Cleaned up my old Hafler amp. Repainted the top. Then painted on a HAGLABS
logo. Oops, I didn't tape the newspaper down so I got some overspray. Doh!
Messed up that paint job. Anyway, will put this amp back into service for
PA-10 comparisons.
I think I'll hold off on converting the assembled FRYKLEANER stuff over to
HAGLABS. Too many other things on the plate right now. It can wait. I did,
however, buy a sample red translucent case for the FRYBABY. Main goals right
now are to get the CASTANET kit out the door and HAGLABS website launched.
That is, with actual product. Six of them. People are again asking for
TRUMPETs and VACUTRACEs.
Huh. This was wierd. In a great way. Got the Hafler working, gave it a day
of burn-in. Ok, let's try this out. Hooked up the vandys, CHIME, etc. Dang,
one channel is all noise. Must be some lizard shit on the transistors. Hmmm.
So I ran one channel, did a whole bunch of A/B with the same channel on PA-10.
Hey, they both sound like crap. That is, the thinness is all due to the awful
listening room conditions. The big SS amp didn't sound any better. A little
more punch and better bass control, but otherwise tonality was about the same.
Ok, run one amp per channel, stereo. I have to admit, it was suprising how
well they imaged. Seriously, I had a pretty good soundstage. But here's the
weird part. I could hear the left speaker, but not the right. I could stare
right at the right one and not hear it. All of the sound was imaged between
the speakers, yet it was easy to precisely pinpoint the left one. Well, I'm
hoping that is because the right was powered by the PA-10, not due to odd room
effects. All listening was near field. I moved from five to six feet away.
Slightly up and down. Yeah, still the imaging is better slightly above axis.
I can't figure that one out. Once I got used to the room, I could hear the
full range of music. Nice to have a bass line. Some tracks like Jack Johnston
"upside down" from curious george really likes to have a bottom end to give a
pace and rythmic flow. It really sets the foundation for all of that
percussion layered on top. And so, I thought maybe I had really messed up with
this PA-10. But it was mostly room. And the vandy came out fine. Maybe a tad
bright on top, or perhaps that was the Hafler. Even with its obvious technical
flaws, the PA-10 ended up being transparent and musical. The fact that I could
NOT hear that speaker was key - that is, pinpoint its location. Oh yeah, the
other good news is that I got the polarity correct!
Nov 07
------
I need to make a new listening room. A second one. Heck, my 1st is still all
torn apart because of the construction and painting I did. But I think it is
time to make more room in the shop for parts. So I'm building a new area for
testing. Convenient to have it right where the vandys are sitting. Terrible
acoustics, but it's safe from dogs and kids. My Pete Riggle VTAF just came in,
so I'll put that on the Rega and move it into the house. I need a much better
stand. Acutally, I might already have one. Just need to spike it. Anyway,
expanding. Hey, the more I think about it, our master bedroom should have
quite good acoutsics. It is well broken up and has a built-in bass trap. I
should try that out. Cement under the wood floor. Should be perfect for a
turntable. Hmmm, now I don't know where to put things.
I am so stupid. Just checked out the acoustics in the bedroom. They're f*ing
excellent! Why did I never think of this before. It has wonderful sonic
features, bass trap in back (closet full of hanging clothes), behind the
speakers I can open windows in the corners, walls are all broken up with odd
features, ceiling is vaulted. Shoot, it's incredibly dead, non-echo. There is
a perfect spot to the side for a table and rack. All I need to add is a small
rug in front of the drivers. I'll have to lounge on bed for listening, but how
bad can that be? This should evolve nicely. Even the Maggys should eventually
fit. Screw the living room.
Tried out some different fancy yellow LEDs. Various currents, how they look in
the red panel. I like the #67-1126 from digikey run at 5mA. It has 1.88V drop
across it. Was hoping for less current, but this is what it looks best at.
Designed me new ARCHIVER panels today. These are made to fit into a proper
chassis, one with top and bottom. Awesome chassis I found for $41. Panels
cost a fortune, but hey, this is hi-end. Needs to look the part. I'm adding a
BUGLE power supply to it, see if that helps anything. Looking into possible
capacitor upgrades. One thing I finally decided to do was to remove the XLR
outputs and just go with RCA. Suppose I can do XLR on a custom order basis.
In fact, I think I'll revert the new TRUMPET to that too. Make it RCA only,
customizable to XLR. I like that better than trying to have both.
Ok, hooked up the PA-10 to a vandy. Mono only, put on a CHIME. Well, I guess
I am so far underwhelmed. Very midrangy, recessed. Not too dynamic. How much
of this is due to one channel? Anyway, seems to have much less bottom end than
the CYMBAL did (why the frick did I sell that thing?). Maybe I am realizing
the CYMBAL was way better than I thought. It seemed to have it all. Except a
lot of power. I should have kept it, at least as a reference. Anyway, I got
some more things to try on this amp. I can clean up my Hafler to run the other
channel. Meanwhile, moved the TT inside. No idea when I can get to the VTAF
upgrade.
Nov 06
------
Got it! After futzing all morning changing around caps, making new CCS, I
finally stumbled upon the problem. Doh! The pin 1 of the right side 2A3 went
into the socket too deep and shorted to the grid trace. Stupid. That's why
the grids always shot up positive. Anyway, a simple insulator did the trick.
Now everything is working quite well. I am wondering how much I can back track
now to restore the original circuit. The cap change stays, as the booch caused
that brilliant insight. I should try listening to it.
The PA-10, not suprisingly, ends up being an awful lot like the CYMBAL. Here's
what I'm getting at the moment. 6W output power prior to clipping, 0.5% disto
at 1W, 0.5V input sensitivity, 45mA on each tube at 238V, -47V bias, 17Hz to
27kHz @ -3dB. I'll see what I can do to improve on distortion and bandwidth.
There is a slight but very well behaved overshoot in the step response.
Ok, a little tweaking. Still has a bit of audible hum and buzz. Output
impedance measures in at 4 ohms. Higher than I had hoped. Hmmm. We take 500
ohm output on anode, 12.5:1 turns ratio, that's 3.2 ohms. Two tubes in
parallel should cut that in half. I need to shift the current up another 10mA
or so. Changed coupling cap to 2.2uF and bass response is now -3dB at 9Hz.
The top end is having some trouble, due to the interstage tranny. I am getting
a 1.5dB peak at 16kHz, then 0dB at 20kHz, to -3dB at 27kHz. Fast rolloff.
This appears to be transformer related, as the driver pushes the grids no
problem. I wonder if I had the wrong tranny leads hooked up? I'm only using
one of the secondaries for 8 ohm connection. They recommend both.
Nope, that didn't make any difference. Hmmm. I wonder why the bandwidth of
CYMBAL is so much better. Even the CLARION was way better than this. I do
lose a bit from the interstage, but something is dragging down the output. Is
it the higher output plate impedance? Did I even install a Hammond 1615? And
so I got to thinking about the really wierd way they wire up these trannys.
They give these connection diagrams.
4 ohm8 ohm16 ohm
And so I thought about how they do this. The answer is that it ain't really an
8 ohm connection, but 9 ohms! Seems to me they have two primaries, probably
wound in bifilar, and six identical secondaries, which they then internally
strap with some in series and some in parallel. It looks like this.
Hammond 1615
I figure the turns ratio is roughly 35:35:1:1:1:1:1:1. Probably a very good
construction architecture. Two of the secondaries are wired in parallel for a
1 ohm output. Then there are two other sets of two secondaries in series, each
giving a 4 ohm tap. Put these in parallel and you still have a 4 ohm tap. Put
the two 4 ohms taps in series and you get 16. Put all of them in series and
you get 25 ohm. Here's the kicker, doing a 4 ohm in series with the 1 ohm
gives you 9 ohms, not 8. Hey, close enough! The 9 ohm wiring recommendation
is meant to even out the winding resistance, basically 3 secondaries in
parallel with the other three. It does make sense. This odd configuration
gives you 1, 4, 9, 16, and 25 ohm options for a 5k primary. See the pattern?
That's one-squared, two-squared, three-squared, etc.
Ok, that gives me something more to think about. I also need to put back in
the common mode hum cancellation trick (also from western electric), and then
tune the parallel vs. differential ratio for distortion cancellation. Up the
current, see what is killing the bandwidth. The CYMBAL had a similar issue
when I connected a 1608, which made me change to the 1615.
Nov 05
------
That amplifier for maggys? It need to have more power. I want 50W or so. The
good news is that can be designed for maximum power transfer, have an output
impedance of 4 ohms. Nice and high. Design the output stage thusly, build it
with two channels and a line-level xover inside. A bi-wire amp. Heck, why not
make it specific for the maggy 1.6? There are sheetloads of those panels out
there. It is a market unto itself. This might have to be another HAGTECH kit?
The big issue in front of me is, what tube? I need a kick-ass triode that is
linear. And that ain't the 6C33.
Oops, discovered I left that 7788 connected as tetrode, not pentode. Pin 8 was
floating. Here are the corrected curves.
7788 pentode7788 triode7788 triode reference plot
My best guess at values is rp = 2.5k, mu = 50, gm = 20mA/V. This is at bias of
Va = 200V, Vg = -3.0V, Ik = 20mA.
Man, I am having some trouble getting this PA-10 to fire up. Can't get the
CCS loading to turn on. Makes no sense, unless the transistors are blown.
Which is possible after what I've done so far. The design is really cool, but
I made the mistake of concentrating on steady-state conditions. Doh! I forgot
to consider power up transients. Just noticed that the RC time constants in
various places cause some very bad things to happen. Crank! I reverse bias
some electrolytics, which then push the 2A3 way into cutoff. Oh crap. I've
made a mess. Sitting at the scope & DVM didn't do it. Sat there with
schematic in hand. Just thinking. Wha, no, yes, huh? Eureka. Came up with a
major change that solves a number of issues. Wow, big. A total redo of the
output stage caps. I need only two of them! This solves power up, and makes
the current loops even smaller. And I am starting to hate the CCS design. So
for now I am just going to rebuild the stage and use 820 ohm pull-down
resistors instead of CCS. I was doing too many things at once. Need to get a
basic version up and running first. Then I start adding CCS and feedforward
stuff. Wow, this is way cool. I may not even need the CCS.
Nov 04
------
The serpac cases came in. Wow, these are beautiful. This will make for an
awesome new VACUTRACE. Also got in parts to finish the CASTANET board. This
is really starting to shine. It has attained that rare holistic synergy. Very
much in tune with itself, everything fitting and playing together like a glove.
The board with parts alone is 7.5 pounds. That's without any chassis! Been
upgrading parts here and there. Big 2" long 3.3uF caps from Cornel-Dubilier
(super polyprops), silver plated fuse clamps, ceramic fuse, high grade low
impedance electrolytics, etc. All without busting the budget. Just waiting
for the panels to come in. Then I think I can write manual, order production
boards.
Always on the lookout for various tricks. Bought some pickup truck bed liner
spray today from the auto parts store. I want to try this is a damping
material, see if it is any better than the cork/rubber adhesive strips.
Trying to get the PA-10 fired up. Looks like maybe the lower CCS aren't
working or the 2A3 has problems. Much interconnectedness, I wonder if I made
a latch condition. The 2A3 are supposed to heat up first, followed by B+,
which then gives some voltage for the CCS to work into, thus allowing the high
voltage LED to turn on. I get B+, the driver stage biases correctly. Dunno
yet. So I took the time to make measurements of the 7788 driver tube. Made me
an adapter card for the VACUTRACE. Measured me two older (1964?) Amperex "PQ".
In tetrode mode got a very noticeable kink.
7788 tetrode
I forget if this was 0.5V or 1V per grid step. Not sure where zero is. H axis
is 50V/div plate, V axis is 12.5mA/div. Screen was approximately 200V. The
looping in the curves is due to the screen supply droop in the VACUTRACE. It
isn't really there. Ok, so now triode mode. I did some static measurements at
about 180V plate/screen @20mA. Transconductance was off the scale, plate
resistance was 2.8k ohms (somebody said it was about 1/2 this?).
7788 triode
Not bad, but that kink is still there! In fact, it's huge. But from -1V grid
onwards there seems to be no effect. Quite linear, actually. I was really
worried when I first saw this, but I think I am ok, at least in the region
where I plan to operate it. I would estimate mu to be about 50. So yeah, that
makes this a bit of a supertube. High current, high gain, low output impedance.
Here is the same tube but zoomed into 5mA/div.
7788 triode zoom
In my opinion, this is awesome linearity. Visually way better than most tubes.
Hey, my earlier estimate at -2.5V bias at 180V for 20mA was right on the mark.
Nov 03
------
Had this idea to use the new VACUTRACE box for the COMPRESSOR too. It would be
an intersting solution. Fixes a number of issues with the design, plus it
makes it very unique in the marketplace. A rugged portable mic pre chassis,
not the typical rack mount stuff. I think this would be much more versatile,
and you could make the mic cable runs shorter. Something tells me all that
capacitance sitting on a mic output is similar to what happens to an MM cart.
UA makes a portable mic pre. With handle! I'm not that far out. Anyway, just
thinking that since I have this fabulous circuit, I could offer the machine in
a new format. It costs more, but I'll just have to charge whatever it turns
out to be. Besides, I really want one of these things for my own use. Yeah,
after we get the TEN series out there, it's gonna be home recording time. I
think this will give me a whole new battery of listening tests. That, and I
get me a pair of Maggys. Oh yeah, the COMPRESSOR is a great reason to try out
the cinemag trannys.
Nov 02
------
This is starting to look like an advertisement for Hammond.
Hammond chokes & trannys
It's actually a CASTANET. Note how I moved the power supply chokes to minimize
hum induction. Clearly there was some stray magnetic coupling between the
first choke (lot of volt-seconds) and the parafeed chokes. No way to stop it
except via distance. So I made fields symmetrical about the channels, then
moved the first choke as far back as possible, then oriented it such that the
corners lined up. That is, a 45 degree angle on the bobbins. You see, the
bobbins are square, not round. This means the windings are for the most part
square, with flat sides. The external field is a cross product vector, and
perpendicular with the wire direction. In other words, the external field is
strongest out the flat sides, and minimal at the corners. Bingo! Line the
bobbins up for minimal coupling at the greatest distance. When I tested this
out on proto #1 it worked just fine.
I got just tons of parts on order. The HAGUSBs keep rolling, constantly buying
parts for them. Have expensive panels for just about everything else coming in
like the new TRUMPET and VACUTRACE. New CASTANET panels. Ten new projects at
once. That's a bit insane, except they have a lot in common, and I needed to
set up the architectures in sync so that the product lines all match visually,
electrically, and mechanically. New chassis for ARCHIVER due in too. Yeah,
this sort of R&D spending can sink you. But not to worry, I just secured an
additional $20k in financing. That should cover the prototype expenditures.
Meanwhile, I have to start signing up some dealers or a distrubutor for the
initial HAGLABS stuff. Am I doing the cart before the horse? I dunno. Need
to get someone selling the red TRUMPETs and red PICCOLOs for me. The HA-10 is
also right around the corner. My goal is to launch Jan 2008. The PA-10 might
not be too far behind (which reminds me I gotta debug that board), with the
rest coming online at RMAF. Red. Everything is red. In fact I just bought
some silver wire today covered in red teflon.
This weekend I am setting up another workbench in the shop (expanding around
the corner). This will be for assembly only. It will be for the hired help.
Also might set up me paint shop.
One issue I am having trouble with right now is the thread-forming in the
chassi extrusions. I have been doing it by hand. What a pain! It leaves too
much shards. I would like to automate this process. And find a way to clean
up the material afterwards.
Ok, fired up the PA-10 proto. Finally. Thinking this is gonna be a tough one
to debug. Powered up with no tubes. No smoke. Not sure what else I can do,
so plugged in all the tubes and went for it. Still, no smoke or pops or bangs.
Heaters came up, but the current sources weren't. I need to make a prop to
hold the cover off so I can probe inside. Better check polarity of the zeners
and transistors. Here's what it looks like.
PA-10 proto
Looks reasonably simple from the outside. Inside, though, it is packed full of
stuff. Components both sides. Here is the bottom.
PA-10 guts
And I changed my mind again. Decided I just didn't like the looks of the
toilet seats. So off they came. Instead I tried to mount the spikes directly
to the base of the cabinets using some 1/4-20 inserts I bought. Well, except
that these cones are not 1/4-20. Nor 10-32. Sheet, they're M6! Great, I
can't find metric inserts anywhere, and now I have these big holes drilled. So
to just save time, I hard glued those cones in place. This ends up giving them
a better (harder) coupling to the box. Screw the threads, I say. Ar ar. This
time I reversed the order. The toilets and original stands had two feet in
front, one in back. It now has two feet in back, one in front. Just made more
sense to me.
Nov 01
------
Had this idea, mark boxes or maybe products with the HAGLABS logo in paint.
All I needed was a stencil. The logo was specifically designed with this in
mind. Hey, I have a CNC. Shux, I just write a quick program and cut my own.
Took two tries, but I got it nailed. Actually came out nearly perfect. Made
it two inches tall. Can't wait to try it out. But on what?
Logo stencil
Realizing there is something unusual about the maggy xover. Didn't hit me
right away, but normally crossovers are designed with the -3dB points set the
same. Here we have one at 500 the other at 1600. How is that going to work?
It just means the drivers have a response of there own. Noticed a comment
somewhere that talked about the rising response at 1k. Well, there it is.
Also, one of the changes from a 1.5 to a 1.6 was lowering the crossover point!
Ok, so perhaps my idea to raise it by changing the LP section is bad. Maybe
that is exactly what they used to have? I dunno. But seems to me the only to
start answering some of these questions is by measuring an actual panel with
crossover removed. I wonder if Stu has some.
Oct 31
------
I'm thinking now I should not have sold my CYMBALs. Probably should have kept
that amplifier around for a reference. Cost me about $2k in parts to built it,
sold for less than $1k. Beautiful machine. I hate to see it go.
Here's a photo of the new VACUTRACE chassis. I don't know why I didn't think
of this earlier. They also have a smaller one that can be used for holding the
adapters cards. Handy. Not only is this way more rugged (and cool), but it
makes the machine far more portable. All cables, cords, cards, etc. fit into
the two carrying cases. Now that I think of it, the FRYKLEANER should have
been designed for such a box.
New VACUTRACE chassis
Worked out a faceplate. The mechanics are very similar to the original, but
with the controls slightly closer together, the OUTPUT knob moved, and bringing
the BNCs and power cord stuff to the top. Added some handles. This will look
fabulous. Ordering parts.
New VACUTRACE panel
Meanwhile, I am re-doing the ARCHIVER in red, giving it a real chassis. Right
now it is open-frame style, made for professional use in studio racks. But I
think this will work for home hi-fi too. And so I am designing it to fit into
a 2U chassis. This will also shift over to the HAGLABS brand. I likely may
leave off the 16-bit digitizer - that seems to have missed the market. So now
I can have both XLR and RCA outputs. This will be just like the red TRUMPET!
A good match, these two. Even more interesting is that there is an audio guru
out there who likes it enough to consider OEM-ing it. That is, build a version
to their specifications (part selection, colors, etc.) for resale. I'm ok with
that. Never expected this to be a huge seller, but it definately is a unique
machine.
Lots happening here at HAGTECH / HAGLABS. I realize it may seem very confusing
and changing day to day, but there is an underlying plan. Basically, it is to
create the HAGLABS brand and sell upscale assembled units. At the same time,
reduce HAGTECH to half-kit only status, plus maybe a few of the lower cost
assembled machines like the HAGUSB. One brand sold via dealers, the other is
factory direct. Both approaches work, I am merely trying to re-organize them
as separate entities. Hopefully, I can develop the technologies and
innovations for HAGLABS, and then trickle it down into suitable kits for
HAGTECH. That is the plan. And right now absolutely everything is in play.
Ok, every once in awhile I take a break from the grind. Looking up more stuff
on the maggies. Trying to figure out what to do for a crossover. The stock
version has 2 pole low-pass and one pole high-pass. Tweeter inverted. Hmmm.
Looking at the acoustic measurements, one can see that both respond to -40dB
per decade, or two pole response.
Maggy 1.6 response
Now there is mention of an acoustic crossover. I'm thinking what is happening
here is that the tweeter dimensionally has the equivalent of a one pole rolloff
(like a horn). Heck, there is only so much the small surface area can do. So
the combined electrical and acoustic networks gives you a nicely designed flat
curve. The problems are impedance peak and goofed up transient response. Ok,
so we can fix the impedance issue by using an active crossover and bi-amping.
We can also easily match levels. The issue now becomes what can be done to
make the acoustic response perfect. I think a natural first start is to mimic
the crossover as is. The possible improvement comes with solving for time and
phase alignment (no inverted tweeter). This article does a great job
explaining a couple of the more common choices:
Crossover article
From it I am guessing that the stock system mimics the LR-2nd order variation.
A good compromise with it's simplicity. I can't help but wonder what sort of
sonic improvements can be had by fixing that inversion. You know me, I'm a
transient response fanatic. The question is, how to do it simply without
making a mess of things. The good news is that I can build dummy networks into
the PA-10, such that they can be easily modified for bi-wiring, without having
to use an external xover box.
Back again. I did some quick sims to get a feel for what the maggies were
doing. The stock filter values have the HF corner at 1.6kHz and the LF corner
at 500Hz. Approximately. Trying to replicate that above measured response, I
added an extra CR high pass at 1/2 the HF corner, or 800Hz. This sort of gives
me what I see in the graph.
Stock maggy xover in SPICE
As you can see, there is a big dip in the midband (blue). Naturally my
inclination is to see what more I could get out of the woofer. That is, move
the corner up. Keeping damping the same, I rough out values of 1.5mH and 10uF.
Ok, now crossover is at 1kHz, but the dip is WAY less. Now look again at the
measured plot. There is a broad resonance at 1k by the tweeter. Looks to me
like there is a lot more than what meets the eye. That's why I shifted the
woofer up, it now has a small dip centered about this 1kHz peak. Ideally they
should tame each other. However, who knows what might actually happen.
Shifting LF corner up
Anyway, this would be my first test. Try a 1.5H with a 10uF on the low pass.
Oct 30
------
Reading new issue of TAV. Yeah, that might be what I am looking for. The
Magnepan 1.6! That my be the right speaker for my living room. But I had
always heard panels were so hard to drive. So a little research. Plenty of
info out there, seems to be a fanatical crowd (a good sign). The question
becomes, how to drive them? That would mean a new amplifier? I suppose the
4 ohm output of the PA-10 will do ok, at least at low levels. Quality and
clarity without volume. Looks like the answer is to bi-amp, use a line level
crossover, put the drivers back in phase.
Ok, so maybe I am a madman. Once again shifting in the wind. After a lot of
hand wringing, I decided not to do a VACUTRACE kit. It's just not worth the
hassle. You have no idea the debug support that would be required. It's a
really complicated circuit. Not for audio DIY. And so I looked into making it
in frontpanelexpress rack mount form. Something maybe a little nicer? The
problem was one of chassis for the backside. And then I realized, shoot, the
dang chassis I use for the TEN series might just fit. It doesn't, but is soooo
close, I had to see what could be jiggled. Sure enough, the trick is to mount
the tranny to the panel and not the board. Then move the OUTPUT control off
too the side. Shux, I am really suprised this might work. Not only do I end
up with a better chassis, but I can make it match the other HAGLABS equipment.
Stay tuned. I'll build one up to see. Honestly, this would be a great boon to
getting HAGLABS off the ground. I'll have TRUMPET, VACUTRACE, PICCOLO (red),
and the HA-10 on which to launch. The UFO can also move over, get the upscale
brand name. Hmmm, the FRYBABY belongs there too, as it is already a dealer
product. Ok, that is 6 machines for the grand opening. Also thinking of doing
an upgraded ARCHIVER in red, with both XLR and RCA outputs, no USB ADC, and a
nicer internal ac power supply. It really is a great sounding unit and belongs
in the HAGLABS class. Seriously, the $1000 assembled machines do NOT sell at
HAGTECH. Too much stigma from the kits. Don't know what to do about pricing
yet. The VACUTRACE likely will not have the normal dealer markup, expect about
$1500 for the new version.
Looking at paint tools online. Dang, looks like I can get a compressor and
paint gun for under $200.
Oops. In my zeal to work out the vertical fit issues I neglected to see the
obvious, where a 10 inch board doesn't fit too well in a 9.3" chassis space.
Doh! Crap. I was feeling lucky. There was a portacab version, but it had 18"
depth when I only needed about 5". Must ponder some more.
Didn't sleep well, but came up with an improvement to the rack. Change to some
round dowels, like a wooden closet pole, use them for legs. The round shape is
nice for spiking. Anyway, as I lay there thinking about bi-amping Maggies, I
realize that is four monoblocks. The old style rack is too tall. How about a
side by side approach? Two legs in the middle, bolt to chassis. One leg on
each outside, on rear of chassis. This is more of a triangular topology, and
has the interesting visual effect of leaving the front panels hanging out in
space. No front legs on the outside. Might look cool. Anyway, it's an
alternative connection to the standard 4 poster. Same parts.
Ha! I knew it would come to me. Actually, this was an idea from several years
ago. Use the serpac #R520 case! Duh. Talk about test equipment, this is a
perfect fit. And cheaper, too. Use the #R120 smaller case to carry the cables
and adapter cards. Curve tracer to go. Plenty enough room, no games. I can
make this look real nice.
Oct 29
------
And so I thought, hey, just get an older Mac Mini on eBay. They go for $300 to
$400. Thinking that should be my new transport. No keyboard or monitor. Just
run it as quiet as possible. Well, except for that damn switching power
supply. Have to give that its own circuit. Anyway, turns out I can do some
simple control via the USB audio connection. Like play/pause, skip, stop. So
a small box, stick in your CD. Control it via the DA-10 remote. The mac mini
also comes with it's own remote, so maybe it's not such a deal.
Should get the HA-10 boards tomorrow (rev 2). Maybe by the end of the week I
can have a fully functional pre-production quality headphone amp. Good enough
for web photos and to prove out final board changes. Then get them production
boards on order next week. That puts me on schedule for a Dec 01 CASTANET
launch.
You know, all this speaker work gets me to thinking about turntables. I know
it is an area I should probably avoid, but something inside me really wants to
build a turntable. Gads. It would be something simple. My brain is leading
me to think of an MDF brick. Stack several layers of MDF and then machine it.
All one big plinth as I just can't get into the difficulty of setting up
multiple pieces, like a tonearm base you have to position manually. Maybe rim
drive. Maybe direct drive. Dunno about ac or dc, but the box would definately
have custom HAGTECH electronics. Guaranteed spots for more than one arm. It
would be assymetrical to lower boundary resonances. Even the platter MDF. All
painted shiny. Seems to me the right coat of paint would act as a decent vinyl
interface impedance. You don't need felt or rubber or teflon or PVC, just the
right paint and thickness. It would run at 78rpm. And 16 too. Er, I better
stop thinking about this and get back to the TEN series. Who do I think I am,
Tim D.P.?
Oct 28
------
Tweeters came in just in time. Now I can fire these babys up and listen using
my CYMBALs, which sell tomorrow on Agon. But I noticed the tweeters need to be
modified to fit. That must be the -46 version. The bottom part of the rim is
chopped off. Well heck, how many of us have a $2000 CNC machine sitting
around? Turned out to be an easy mod. In fact, my cut was cleaner than the
original.
Tweeter installation
Put them in the living room ready to get hooked up. Took some photos. Got up
this morning and the dog had pissed on one of them like a fire hydrant. Ay ay
ay. How's that for kharma? Shoot, maybe I move them to a safer room. Anyway,
here's what they look like in a real room.
VandyVandy
Moved speakers into the guest bedroom, rearranged furniture to see if I can
make me a new listening room. One free from pee. It's not a very ideal space,
lots of bare windows along one wall, anything but rectangular. Wood floors,
nowhere to properly place anything. So I went diagonal, with a corner in the
middle. Speakers too close to side walls. Lots of reverb in this room, much
worse on left channel. The closet behind me acts as sort of a bass trap.
Brought in the CYMBAL GOLD and CHIME GOLD, hooked it all up. Dead quiet
background. I can only hear a bit of tube noise with ear right up to tweeter.
Ran the laptop into USB. Big problem is that there is NO volume control with
this setup. I have to run loud only. Whoah, was getting a bit of shout. I
was getting music, but something on the PC got messed up and the usb-audio
driver wasn't working. I think it is from whenever I use the EMU-0404 in the
lab to measure distortion. The drivers crash each other. Ok, so playing some
MP3s. Sounded pretty awful. Dull, midrangy. Ah, I just switch to directsound
or whatever it is called. Then foobar worked on the flac files. Much better.
Night and day. Still way too much wall reflection on the left. So I toed
the speakers way in. Better. Not far enough apart, though. The soundstage
was very narrow. Not getting a full disappearing act. Interestingly, the
stage images better when standing, as if in-line with the woofers. Clarity
and convergence work better on tweeter axis. A better coherence from top to
bottom that way. Still, the room was so bad it was hard to get a good feel
for these things. They showed potential when driven with decent material.
Tone was well balanced from top to bottom, definately my changes to the
crossover didn't mess anything up. I did notice the bottom end seemed to go
way deeper. It was as if I wasn't missing anything. These were now full
rangers. However, the very bottom was muddy and not articulate. Deep male
voices were fine, but the bass and organ notes way down got all messed up in
the room. Still, it was nice to have them. At such volume (I was using all
six watts) the floor was shaking. Could not quite get rid of the shout either.
No time to play. The good news is that they work. Tweeters probably need
some break-in. Room sucks. Must get volume control.
Small listening room
Oct 27
------
Got the woofers installed. Forgot about the damping cushion behind one, had to
pull it and re-adjust the wad. Doh! Figure that is part of the design I am
not willing to mess with. Anyway, all I need now are tweeters. From a good
distance these speakers look pretty nice.
Vandy
Then again, full sunlight is not the best way to photograph these things. Here
you can see the spacers for the floor cones. I get about the right tilt from
them. Have to re-read the instruction manual on placement. Methinks the
tweeter needs to shoot upwards towards listener level. Hey, these cabinets are
quite heavy.
Vandy tilt feet
I added a handle to protect the binding posts. Was going to add more handles
on the sides, but I think I'll skip that.
Vandy rear
Which gets me to thinking. I need painting capability. Pro style. Yeah, I
think it is time to invest in a compressor and real paint gun and equipment.
Never looked into it, but hey, it can't cost that much. I really want to be
able to lay down some really clean coats of hard non-scratchable paint. Need
this for my TEN series.
Oct 26
------
Ok, just caught up with all of the backorders. Sorry for the delays. Some of
the HAGUSBXLR had to wait more than two weeks. I was out of cases, then cables
and transformers, then I messed up the CNC machining, then more cases. Yikes.
My inventory control needs help. I've put in about 8 orders in the last two
weeks trying to catch up on parts. And today I discover I am out of battery
holders for the PICCOLO. At the moment, I have no formal inventory control,
just organized part bins. Usually I can see right away what is missing. But
somehow that is not working too well. Especially during hard-core R&D sessions
when I am always in need of some new part. Maybe it is time to implement some
sort of computerized inventory? Hard to maintain sanity with 20 different
products to support. Streamlined and efficient processes are very important to
success. In fact, yesterday on the phone the big-name cable guy asked me how I
can I keep my prices so low.
Got the crossovers installed and glued in place. Added a bunch of silicone
glue to better secure the inductors, too. Once dry, I can put on the binding
posts and woofer. Tweeters not here yet.
Oct 25
------
Engineering is the art of compromise. And I am compromising. Just could not
find a way around that mechanical interference on the PA-10 with the binding
posts and the power supply choke. Nowhere to put them on the back panel. So
on the front they go. Hey, plenty others do it. I can keep the RCA input on
back so that the series still matches up visually. The good news is that I
found a really good set of insulated gold plated binding posts.
Just shelled out for 300 more HAGUSB boards. Also finally got around to doing
the relayout of CASTANET (HA-10). Yeah, yeah, so many projects at once I am
losing focus, needed to get this one back on top priority. Made major changes,
moving chokes, etc. In fact, I ripped up every trace and started all over with
the routing. It came out quite different, using larger capacitors, etc. Will
order proto later today.
Interesting developments in the OEM department. One of the well-known Euro kit
designers is interested in using the HAGDAC in his own machine. Negotiating
details at the moment. Also, just got a call from a major cable manufacturer
who is interested in buying an upscale OEM version of the HAGUSB. How cool is
that? We'll see where it goes.
Finally done painting them Vandys. Put on a coat of clear glossy lacquer
today. Well, maybe that was a mistake. Yeah, I like the stuff, and hopefully
it adds some hardness to the finish. But it sort of accentuates the
imperfections. I admit, the boxes now look decidely home-brew. Hmmm, maybe if
you stand back. Tomorrow, after jamming out a bunch of HAGXLRs, I'll put the
bases on. Maybe this weekend do the crossovers and get the woofers installed.
Tweeters may show up on Saturday.
Oct 24
------
Wow, for only ten times the cost of an ARCHIVER, you can buy virtually the same
thing from these guys (kudos to phonogram):
Expensive variable EQ phonostage
They do have a good listing of EQ info for 78s & such in the manual. And so I
was looking again at my EQ for the PL-10. I had it down to five curves, but
the changes are a bit complex without adding lots of extra Rs and Cs. Way too
many. The problem is the interactions between the bass shelf and the turnover.
I want sonics, not a sheetload of capacitors switched in an out with relays.
And so maybe I will simplify this a bit. Clearly, the big RMAF demo must have
been the Columbia LP curve, with a -16dB cut at 10kHz. The change is bass
shelf isn't that much, especially on the speakers used. If I leave the shelf
alone, then London LP, ffrr LP, EMI, NAB, and Columbia LP will get a slight
boost in bass in the 50Hz region. Maybe I can live with that. It keeps the
circuit simpler and more sonically intact. Then all I have to do is offer
various cuts. They would be -10.5dB, -12dB, -13.7dB, and -16dB. That ends up
covering the entire LP range. Adding in capability to do 78s is another
matter. Then the turnover has to vary. I would need something like a 300 for
RCA, decca, ffrr, polydor, columbia, and american 78s. Then an 800 for RCA.
Well, I like the EQ tweaking, but this doesn't have to turn into a 78 phono.
Let's just stick with hi-fi microgroove. You want 78s, then buy an ARCHIVER
(maybe I can do a red version). Taking this route I can add a -5dB cut without
too much trouble, giving 6 curves, and getting close for many of the 78s (not
perfect). The major ones to have are the -10.5, -13.7, and -16, as this covers
RIAA, London LP, ffrr LP, NAB, HMV, and Columbia LP. I suppose this is what
the Zanden did? Very clever, gets the job done. Adding a -12 includes EMI and
MGM. I still have to look at the circuit, but it probably entails switching
out capacitors. Yeah, maybe I just do the three?
Aw crap. Building the power supply for the new TRUMPET and I discover a huge
interference fit problem with the big 10H chokes. They are too tall. And too
wide. Panic. Ok, after some sweating I find I can use the 156G 9H choke with
some modifications. It fits, just have to drill new mounting holes. Luckily
they don't screw up any traces. ESR is 300 ohms versus 205. That's turns out
to not be a problem either, as I can change resistor values elsewhere in the
circuit to compensate. Except now I have to order four new chokes.
Oct 23
------
Oh my. Number 3 daughter thought my middle name was "technology".
Got two coats of paint on the vandys. Not covering too well. And my lack of
sanding is starting to show up. Yeah, whatever. I think four coats might just
do it.
Vandy two coats
Oct 22
------
I am like constantly ordering parts. That HAGTECH credit card is smoking. So
bought 4 new TRUMPET panels, two CASTANET, and one red PICCOLO. Not cheap this
stuff. But they look real good, and I can customize them practically on the
fly. Still not sure if I want to do the VACUTRACE panel. Found a nice cover
for the rear, but the board doesn't fit inside. Everything would have to be
open-frame, which might not be a good idea. I suppose if the military wants to
order some more, I might use the concept.
Putting stuff up on audiogon. Need an infustion of cash to pay for all of this
R&D. Up to 11 simultaneous projects. Again, I water myself down. Good news
is that I have the new CORNET box/2 manual done, just gotta get it uploaded.
Will start shipping those orders tomorrow.
Most of the speaker parts came in. The cones from parts-express are pretty
nice, especially for the price, #240-717. Also new binding posts #091-1150.
Got both speaker cabs modified, just a little more sanding and then I will
paint tomorrow. What a pain this woodworking is! Splurged and bought some
clear lacquer. Thought I would try it over the paint, see if I can get a gloss
finish. Installed the cones onto the toilet seat covers. Seems to have come
out ok. The amount of tilt is adjustable, I found these wooden (maple?) end
caps for closet rods. The perfect size. I use them on the front cones as
spacers. The other 4 holes are for bolting these things to the bottom panel.
Removable for shipping.
Vandy new tilt base
Oh yeah, I got the new chassis in for the new TRUMPET. Wow, these look tiny!
This will be the smallest 8-tube phonostage on the planet. I'm actually
pretty excieted about it, as the new chassis solves some of the marketing
issues (mainly that the original didn't fit into certain racks). Plus, having
a red PICCOLO to go with it solves the MC gain stuff.
Oct 21
------
If one learns via mistakes, then I must be a genius. Just booched one of the
Vandys today. Was chopping apart #2, when I broke the terminal on the tweeter.
Doesn't look repairable. Shoot. It's a vifa D25AG-46-06, which doesn't show
up in a search. They got a vifa D25AG-35. I'm assuming they're either the
same thing or the -46 was a special mod for the Vandys. Well, I'm not about to
redesign a pair of speakers. Everything is so interactive. Ya can't just
stick any old tweeter in there and expect it to work. So I buy the -35 and
hope for the best. I'm not making any crossover modifications except for
jumpering across the raychems and using fixed resistors for the L-pad. All of
the caps stay. The internal box design stays exactly as it was. I merely hope
to reduce some of the box colorations by gluing on external braces. If
anything, it's gonna look way cool. Both boxes now glued and boarded up. Did
some sanding and patching. Hopefully I can start painting tomorrow.
Oh, had a thought on a possible panel-mount VACUTRACE design. Looks like I
should be able to make a 19" rack panel that holds the board and tranny on
backside, all of the controls. They would be side-by-side. Controls would be
moved a little closer together, but I think this can work. This solution would
provide nice lettering for the controls at a reasonable cost. No investment in
chassis necessary. Panel is 3U, 5.25" high. I'm not sure what kit builders
are interested in. A nice rack mount or a hand-lettered version of the
original chassis.
Oct 20
------
From Fortune mag:
"Unless you offer consumers something unique, the low-cost producers will win
the battle every time."
Oct 19
------
Well, I has a mess of a time doing just the simple measurement of the 1C's
impedance. Tried doing a white noise into my old (rebuilt) Hafler into an 8
ohm resistor and then to the loudspeaker. Using the computer and my EMU-0404
and wavespectra I could not get much meaningful data. The plot just looked
really flat and noisy. So I backed up to the old school method. Used a sine
wave generator and then read result with ac meter on my HP333A. Same way I do
everything else. Ok, so at 1kHz I calibrated and got almost a perfect -6dB
response. That means impedance is 8 ohms! Anyway, swept and took data at all
of the notable points. For the most part it was quite smooth with no ripples
or dramatic shifts. There were peaks at 23Hz and 56Hz, with the dip at 35Hz.
I'm sure that means something to you speaker folks. At very high frequencies
it seems to drop to 4 ohms. Don't know how much the crossover Raychems heated
up, as the drive level was 1.0Vrms. I would call this a 6 ohm speaker.
Tweeter control was set to 0dB (unmodified speaker).
1C impedance
Ok, so if I drive this with an amplifier having a DF of 4 (output impedance of
2 ohms), then the voltage level measured at the speaker terminals will vary by
2dB. At 10 ohms there is a -1.6dB loss, at 4 ohms a -3.5dB loss. The
attenuation would look something like this.
Loss due to 2 ohm amplifier
That's not really too bad, considering the acoustic response variation one
usually gets out of a speaker. Heck, +/-1dB ain't too shabby. Still, I think
there will be a slight loss at the top end, so maybe I'll just jumper across
the L-pad that used to be in the crossover. I think that will bring the
acoustic response back up to flat (equivalent to +1dB setting with -1.5dB loss
from amplifier). For reference, the output impedance of the CYMBAL amplifier
is about 1.6 ohms. The new PA-10 will be in the same ballpark. A typical SS
amplifier would have no significant attenuation losses at all, the plot would
be a flat horizontal line.
I was hoping to do an acoustic anechoic (outdoors on grass) response of the
speaker, as I have a wideband microphone (AT2020) on hand. But my troubles
with the computer measurement stuff makes it not worth the trouble. I don't
think I can get any meaningful data out of it. I am left with nothing but
listening tests.
Oct 18
------
I tell ya, I am having the most fun with this loudspeaker tweak. No wonder you
guys like DIY so much. But I'm not sure I am doing the right thing. Making
wild guesses here as to how to proceed. I realize I should be using MDF, but I
really don't want to mess too much with sawing. So I bought various sizes of
boards. Pine was too soft, mahogany too hard, and the douglar fir seemed just
right. Using the knuckle test, anyway. This made life so much easier. I can
saw boards pretty easy with a decent right angle. And so I glued and screwed
pieces here and there to the outside. No idea if this works. My concept is to
add external bracing and damping of the larger flat surfaces. If anything, I
succeeded in making the damn things heavier. Starting to look really cool,
though.
1C bracing
And speaking of sawing. I found the perfect solution for a new base. Don't
laugh - a toilet seat lid! Shoot, it's just the right size, made of hard wood,
and already sanded and finished. I got a cherry wood one for $32. Trust me,
this is going to look and work fabulous. Hey, for $32 I save myself hours of
work. I also chose to make the cabinets white. Something a little different.
The black drivers will add good contrast. Overall, this will probably cost me
less than $100 per side.
Ok, I just did a rap test. Doesn't seem to be much of a difference in the
impulse sound from the cabinet faces. All that extra bracing has made no
obvious improvement. Hoping the sonics will prove otherwise. Hmmm, I do have
some very good microphones. I could set up a test and do some anechoic (open
air) frequency response comparisons. Except I'd have to completely finish one
before doing the other, in order to make the test fair. Well, maybe I can mark
the spots...
Dug into equalization some more, following Roy's advice. Came up with five
basic EQ curves for LPs. I figure I can forget 78s, for that you need an
ARCHIVER. Anyway, I have these arranged in a circle, as that makes for an
intuitive control, each step being a slight change in some direction, no
matter which way you go. I think it will be killer. Fortunately, the 500Hz
corner does not move. The sequence is Columbia LP -> NAB -> RIAA -> EMI ->
London ffrr -> Columbia LP.
Made some design modifications to the UFO. But I need an investor for that
baby. Someone who can fork over the cash up front and who can then sell them
off. Wes? Here's the best I can do, 100 pieces for $25k. Then you can sell
for $499 each. Decent quality, innovative.
Oct 17
------
I sure am having fun with this speaker project. Sawed off some parts last
night, did some sanding. Starting to look really cool, like a baby Wilson (no
offense to anyone!). Thinking maybe I need to paint it bright yellow. Or
maybe a two-tone. First, I need to find some boards at the lumber yard, get
them attached to the outside for bracing and damping. Buying new binding posts
and cone feet from parts express. The biggest change will likely be due from
the removal of those horrible over-current devices. And now that I think about
it, I bet most speakers out there have them. Think about it, the last thing a
manufacturer wants is to deal with blown drivers. So they protect themselves
from all of those nasty class D amps. Ugh. I'm thinking this may be one of
the biggest DIY tweaks you can do. Just short across the speaker fuses. Only
you have to make sure to use an amplifier with an output transformer. I know
I'll be fine because there is no way I can overdrive the speaker. And my non-
feedback tube amps clip ever so nicely, it's not a problem. I bought these
speakers from Stu a couple years ago, and he had two pair on hand. If he still
has the other pair, it would be great to try and do an A/B.
I decided to make the new VACUTRACE kit only $499. Heck, it is just to burn
off inventory I already carry. I have no parts to buy. So I make it way cheap
for you. It will be a few weeks until I have the new manual done. This is a
steal folks (for anyone who can do chassis work)!
Uploaded new website. Changed coloring of menu just so you will notice. It
has innumerable changes, I can't even remember them all. CORNET is now a kit
with box! VACUTRACE is now a kit only. The MM and MC are gone. CHIME GOLD is
gone. ARCHER is gone. It's all part of a long transition process towards
HAGLABS. As I design more assembled products for HAGLABS, I shift more stuff
into kits at HAGTECH. If you can wait another year or two, eventually the
FRYBABY and ARCHIVER will sell as kits too. CLARINET and CHIME are no longer
sold assembled, although I can do it per request. CASTANET shows up with a
placeholder. I also discontinued the DIYer of month club.
Aw crap. I just ran out of LSK389. Will put in a part order. PICCOLOs kits
will be delayed a few weeks. Always something to order.
Oct 16
------
Worked on the new TRUMPET panels last night, trying to make them have the same
look and feel of the TEN series. Except I think I will still call it the
TRUMPET, not a PH-10 or other. The name already has some recognition, so I
must use it. Here is the ciew from front and back.
New TRUMPET panels
Anyway, I think this is working out really well. Decided to use both RCA and
XLR for outputs. The umbilical is similar to the one for PL-10, but with a
higher number of pins. Everything fits nicely and it is incredibly compact.
This will end up being a visually small phonostage. It is only seven inches
wide. The only thing I don't like is where I put the text TRUMPET PHONOSTAGE.
Probably should not be centered. I will design a panel for the new PICCOLO
today. In red, of course. It will match the new TRUMPET, and can also be used
with the PL-10. The question is what to call it. There is a conflict here if
I sell a HAGTECH PICCOLO and a HAGLABS PICCOLO. Or is there? I like the name
and it goes with TRUMPET really well. I guess one is red the other blue. One
uses more expensive parts (mostly a capacitor upgrade). Is that enough?
Oh yeah, in that HiFi+ turntable setup demo, they showed that many post-1955
LPs were cut using something other than RIAA. Namely the Deutsch Grammophone,
EMI, and one other I forget. Shoot! I need to put some of this variable EQ
into the PL-10. Easy to do, as I already have done it in the BUGLE PRO and
ARCHIVER. I just didn't realize it was necessary. And so I will select a few
extra non-RIAA curves and install them. All selectable by the remote control
on the fly, of course.
I just ripped apart my Vandy 1C. This is my project to rebuild them.
Vandersteen parts
Yes, I took a mallet to them. Everything seems to be glued together. Not the
easiest thing to undo. But first, I did some online research. Went through a
couple of reviews, the old stereophile one by greenberg of the 1B was notable.
From it I can see there are cabinet issues. First thing to do is to get rid of
the dowels in front of the drivers. Bam! I'm going to refinish these in piano
black. Might even put some handles on them (I have to make these road worthy).
I finally get the crossovers out, thinking a cap upgrade is the simplest thing
to do. Well shux, they got nice Wima caps in there. A mix of polyprop,
polycarb, and polyester. And he used the right type for each spot! I really
don't think these need to be changed. The main problem, however, are the
protection devices. They look like Raychem polyswitches, or solid state fuses.
I use these in the RIPPER power supply. The only problem is that these things
are nonlinear and probably the worst thing to put in a signal path. So I back-
engineered the schematic. The improvements to be made are by removing these
devices. Fortunately, I know that I will be driving these with a tube amp, so
no need for over-voltage or current protection needed. No worry about dc
either. Great, the woofer crossover circuit is pretty normal, but with the
fuse bypassed by some large and nice caps. Heck, I'm just going to short
across it. No need caps in signal path. Hopefully this will improve the bass
articulation (one of the reveiwer complaints). Same thing on the tweeter. I
replace the fuse with a jumper. Then remove the pad and install resistors.
Since the output impedance of the amp will be one to two ohms, that should be
about the same as what the fuse was doing. So the pad at 0dB works out to be
1 ohm series with the 5.5uF caps and 30 ohms to ground. I can leave all caps
in place. Lastly, I need to glue the inductor down for a bit of mechanical
damping. I'm suprised it was loose.
As for the cabinets, I have to figure out a way to damp them. My first thought
is to just add external bracing, like bolting some 2x4s right to the sides.
Maybe with a layer of silicone glue between them. Stereophile thought maybe
that large flat front surface had resonances that affected the mid-bass region.
Ok, so I try to break that up. Make cabinet a little more inert. Or maybe I
can just glue on some corian panels. I dunno yet. Anyway, other things to
change are binding posts, screws (non-ferrous), add damping to the woofer
basket, replace felt around tweeter, build new stands, and do a race car paint
job. This will probably cost me less than $100 per speaker. Hopefully they
will be better tuned for my PA-10 amplifier.
Oct 15
------
Oh yeah, you wanted to know about speakers. Well, I didn't find any I liked.
I went looking for something to buy, or at least something to use at RMAF08.
There was very little in the way of highly efficient loudspeakers. Maybe that
day has passed? Only a couple of horn systems. The Zu were out in the court
being used as a PA system, so there was no way to know. But they do have this
way cool triangular shaped box. Again, perfect fit and finish. Everyone is
now applying the most fabulous paint jobs. The Bastanis were quite good. They
went all the way up and down (deep bass). Very open and spacious soundfield,
but lacking, I think in pinpoint focus. Maybe a bit too open. Another speaker
to consider is the AudioKinesis. I don't know anything about them, but worth a
second look. I liked the Fremont from Escalante. Didn't realize they have the
efficieny I need, should have spent more time with them. Hectic, these shows.
Then Spendors were nice, as were the small Ushers. I wonder if I can drive
them with five to ten watts? I will test the PA-10 on my Vandersteens to get a
good feel for this. Oh yeah, the cogent horns in the Teres room were pretty
awesome.
What I liked the most were the panels. The big electrostats or ribbons or
whatever they are. To me, they sounded the most natural and least colored.
I ran into a guy named Robinson who wrote a program for doing digital EQ for
vinyl playback. It's some recording package that I think runs on a mac, looks
very nice. Well, apparently he was not happy with my various forum comments
that doing such reduces resolution by 7 bits (from 16 down to 9) in the bass
region. Something that doesn't happen with an analog phonostage. Turns out he
ended up writing an eight page AES paper (#7185) trying to prove this as
incorrect. Lots of nice graphs. Whatever. I only care how it sounds. And it
seems to me the more DSP you do, the worse things get.
Oh, regarding that bluetooth interface for using a iPhone as a remote control?
I think I know how to deal with that. Just add a serial port connector on the
back panel. I was originally going to do that to allow home theater
installations direct computer control of the preamp. I can still do it. This
also gives the hook to add wireless later. Just connect a small box. And pay
me more money.
Thinking more. Remembering it's not too easy to put the JFET circuit into the
PL-10. Worse is that my variable loading circuit won't go down low enough. So
just remake the PICCOLO into a "red" version! Yeah, the way it sounded puts it
into a $1000 price range. Easy. So why not do an upgraded version with better
parts and better box. I can use the same aluminum box and put a good coat of
black paint on it (now that I know how to paint), then do a fancy red anodize
top panel. Sell it for $599 retail. Even better is that it is the perfect
match for the red TRUMPET. It adds the functions to make it a MC stage. Now I
can have both on sale. Soon. I will also move the FRYBABY over to the HAGLABS
website, as it is sold via dealers. That will eliminate any confusion.
HAGTECH will remain factory-direct with half-kits. And with the renewed
interest in the UFO, I can move that to the dealer side too. Heck, I'm not
selling them direct, but I'm damn sure a dealer could. Just having a UFO on a
table makes for a sure sale. So I fixed the mechanics and priced it out. I
could get away with a $499 retail if I made 100 of them at a time. Silver and
black. Only issue is coming up with the $10k I need to get parts.
Maybe I will change the color of the ARCHIVER and FRYGOLD. Gold didn't seem to
be a very popular color. Perhaps a nice silver with black ink, the way I built
the ARCHERs. Or should I do these black with white lettering? I will then
rename it the FRYKLEANER PROFESSIONAL. So many changes to make in this
transition, I'm getting confused.
Finally, I think the answer to my loudspeaker question is sitting in the lab.
I can do a room demo using my Vandersteen 1Cs. One big complaint at the show
was that everyone was too loud. Heck, with 5W I can drive the Vandys ok. And
they image and disappear nicely. Really not that hard to drive. So what I'm
going to do is rebuild them. The guts looks so cool, so I can chop off the
dowels and remove the sock. Maybe paint part of it red. Upgrade some parts in
the crossover, replace the tweeter control with straight resistors. Perhaps
add in some bracing on the bottom cabinet, like a thicker and more damped
front face. Just add weight on the outside. This could tweak an already great
time-aligned design to new heights. I like them because they are so tonally
neutral. Guess I can keep them. Sure as heck can't buy me a pair of Fremonts.
Oct 14
------
I'm back from RMAF, stayed only 1.5 days. Agonizing 8 hours of flight each
way. But it's actually long enough to sleep the red-eye. Wake up and you are
at the show. Got my badge, stuck the luggage in Thom's room and was off. I
didn't end up taking any photos. Seemed a bit intrusive. Besides, I'm sure
there'll be enough shots online from 6moons, ETM, and PFO.
Worked the crowd, trolled the lobbies. Pressed the flesh. All that stuff your
supposed to do. Marketing. Ok, I'll just do random thoughts as this will be
too hard to organize into paragraphs. CHIME GOLD never got hooked up (Lowther
room) as the power supply for his laptop never made it. Everyone loved the red
panel, but some said it was not a good idea for this market. Be traditional,
they said. I dunno, iPods come in all colors. My phone is red. Oh yeah, all
the hip folks are using iPhones now. Way cool the way it stores and shows
photos! It really is innovative, not just hype. Wes has a whole library of
stuff on there, called up at any time. He had great idea of using iPhone as
remote control for preamp. I'll have to put in some hooks, maybe for a future
circuit board? I only worry about bluetooth wireless interference in the same
box. Anyway, I got tons of great advice from many insiders and those who have
been successful. Basically, the #1 criteria is fit and finish. Cost was not
an issue. Yeah, it's nice if it sounds good too. But it has to look fabulous.
That was the #1 lesson! I suppose it is like buying a car. Why is Mercedes
who they are? Ok, so on the flight home I decide to paint the chassis covers
black making them less visible and focussing attention on the panel, which is
removable, so upgrades to a fancier and thicker panel design can be added
later. I have to think "lifestyle". And so I bought a Vanity Fair for the
ride home. And the UFO was again a hit. I sold both that were there. Maybe
I won't discontinue it. Basically my problem is twofold. Coming up with the
$15k to buy parts in advance, and to get them sold. HiFi+ should have a
review coming out soon. Oh, I met Roy Gregory. Great guy, very enthusiatic,
and put on a wonderfully revealing demonstration of turntable setup.
My best moment came Saturday night. Up in Thom's room listening to various
things. So we put on the ARCHIVER. Hey, not too shabby! It held its own.
The guys loved the EQ adjustability, and it made for a good quick demo. Just
turn the knobs. Then we swapped out the step-ups for a PICCOLO and, holy crap!
The sound came alive. Bass was way better and so was the top end. Shoot,
across the board it was cleaner. I had no idea this box (PICCOLO) was so good.
It just smoked a very popular set of step-up trannys. Now I have to re-think
the PL-10. That PICCOLO circuit must go in it. This is just way to good.
Oops, gotta go to dinner. My nephew just won the Turtle Bay amateur open, and
it is time to celebrate. Not bad for a 15 year old kid. He just romped on
every Hawaii golfer (of all ages).
Oct 11
------
All packed up and ready to go to RMAF! Leave on the redeye tonight. Meanwhile
I get the last few orders out the door.
And I went ahead with a mechanical design of the new TRUMPET. Was considering
names such as PH-10 and PH-20, but maybe I should just stick with "Trumpet"?
It has a bit of industry recognition to it, and that would be a shame to waste.
Besides, it is a narrower and deeper chassis than the other TEN series
components. But hey, it looks pretty darn close, and they will look just fine
together. The problems I ran into are small. Like where to put the logo. I
have it in the middle for now, which is kinda wierd. Going with all RCA
version, so it mates better with the TEN. Although I could do one with XLR
outputs. I should look at it. The I/O connectors move way towards the top of
chassis. As shown, they are mounted to bottom of board (not possible with the
XLR), and end up visually close to center. The 6-pin umbilical does not quite
fit yet, either. I changed the R/G LED on front to a pair of yellow ones,
matching the TEN style. In real life, these chassis will appear to be tiny, at
7" x 3" x 10". It's a very small panel. Oh yeah, the trick to making this
whole thing work is to mount the 273DZ tranformer on top of cover, exactly like
I did on the PA-10.
New TRUMPET panels?
Oct 10
------
Alas, I am underwhelmed with the latest panels. I did the LC-10 prototype in
red with black ink, smaller lettering, and undersized. White ink is way better
and the yellow probably a notch above that. The red is great. I do not like
the undersized panel, though. At first I didn't like the oversized, either,
yet it grew on me quickly and now I am attached to it. I think it's appearance
is slightly cleaner, simpler, and that nice shiny edge matches the shiny edge
along the sides. An accident. The edge, however, is sharp as a knife. The
panel router bit cuts so clean that the edge is mirror sharp and can cut your
finger. I don't think this can be buffed down without screwing up something
else. Anyway, what do you think is better?
Series 10 panel comparison
Also noticed in the Boulder ad in stereophile that they copied my idea for the
flush-mounted yellow LED. Well, ok, they actually beat me to it. But yeah,
it's the same concept. I want to find a way to not have a plastic bezel. Just
a small yellow dot.
News flash! The wife says the recessed HA-10 panel looks nicer. The oversized
one "looks cheap, like you just stuck it on there". Ok then. I go with the
smaller size. No games trying to copy the rest of the industry. We go our own
way here.
Then I was thinking, for the VACUTRACE kit, I can also include a blank jumper
adapter board. This should work out nicely. A very difficult kit to build,
but I know some of you can do it. The major drawback is that the chassis does
not have a silkscreen. You'll have to do a laser printer label or similar.
The good news is that the total cost should be about $800. You also have the
option of building it into a different box, or including a digital output (just
hardwire the USB scope in there). I looked at the manual, this will take a bit
of work, so don't expect it for a few weeks.
And so I thought some more. There I have a pile of TRUMPET boards. No more of
those funky chassis (ok, I could theoretically build two more). Hey, how about
I make a TRUMPET half-kit? I'm sure I could sell off these remaining boards,
if they came with instructions. So I browse through the Mouser catalog, come
across this Portacab. Hey, that will work! Kinda ugly, although maybe retro-
cool.
Portacab for TRUMPET?
The boards fit fine, the tubes stick out top on either side of handle. How
nifty is that? I can redesign the switches and connectors such that you don't
have to buy any of the really hard-to-get parts. Yes, this is possible. Only
god is smiling down upon me, because a few pages later I come across the series
10 style chassis, and wouldn't you know, there is a narrower and deeper one
that fits the board almost perfectly! It wants a 6.3 by 10.0 inch board. Wow,
mine are 6.25 x 10.0. Is that insane? I'm off by 0.05" width, and I'm sure I
can pinch the sides in, because I shifted them a tiny amount on the HA-10 too.
I am giddy at this result. The TRUMPET can be reborn as a HAGLABS product!
This will save a TON of development time. It will look just like the other
HAGLABS machines only narrower. In fact, it will look great. Two boxes, move
the power supply farther away. Done. Decided. No kit. Sorry. I need the
ROI. The only question remaining is do I make the a series "20"? After all,
it will have balanced outputs. Or maybe not. I can build it RCA only. Wow,
this is a real score for me. That is an absolutely gorgeous circuit and I am
so happy to be able to revive it somehow.
Oct 09
------
Just got my issue of stereophile. Good article on step-ups. And so I realized
I did the right thing by leaving a MM phono input on the PL-10, instead of
adding a JFET headamp. This way, the user has a choice of external step-up!
Duh. Just think, for $8k you can get a full phono + linestage with built-in
stepups. And for another $8k, you can buy the AN step-ups. Ha! The Tamuras
sound interesting. Maybe I can fit them into my box instead of the lundahls.
Made a bunch of changes to the website today. But I won't upload until I get
back from RMAF, just in case I decide to make any more changes. The big news
is the removal of VACUTRACE, as I only have one more to sell (and Hammond
apparently lost the silkscreens). I am also retiring the UFO, CHIME GOLD, and
ARCHER. And most importantly for you DIYers, I am opening up the stock of blue
CORNET chassis for sale. It will be a "Box/2" half-kit with two boards and a
chassis for $189.
Hey, I just thought of something. Maybe it is time to change the VACUTRACE to
a kit version again? I have plenty of the boards. The problem is that the
mother board is insane for anyone else to try and debug. I will have to
assemble and test them, just like a HAGDAC. You supply chassis, I supply
boards. I can probably supply the internal cables, pots, and switches too.
Yeah, all I need to do is modify the original kit manual and update parts
lists. Price will probably be something like $499 or $599.
Panels for LC-10 arrived. They were done with blank ink. Hmmm. Very bland.
The yellow will be way better, this is too subdued. The good news is that I
nailed the dimensions on the outlets. Pics later.
Oct 08
------
I have all the parts I need for RMAF ready to go. Well, I never got the HA-10
off the ground, maybe I can power it up later today. Not sure I am going to
bring it to the show. I might be too buys schmoozing. The important thing is
to have the HA-10 prototype there to get feedback on visuals. Also bringing a
PICCOLO, HAGUSB, FRYBABY, and an all-black UFO.
Black UFO
And so I quickly whipped up a new HAGLABS website. Old one was still talking
about the RGP. Did some CSS magic using the new font and colors, and it
actually looks kinda fancy. Especially for being so simple. I want to get a
clean but exotic look. Marketing, you know. Can't be bland. Maybe I need a
black background? I came up with that aqua/greenish color by inverting the
HAGLABS red, or #108080. Use that for the rulers and links. The font is cool.
Anyway, this is just a placeholder. I may end up doing something with a canned
shopping cart software package.
HAGLABS website
Then I had this thought for a decompressor. That is, a dbx-like compandor for
restoring dynamics from CDs. Modern recordings typically implement a rather
heavy hand with the compressor. I'm wondering just how much this can be undone
without totally screwing things up. The idea is to get a little punch and slam
back into CD playback. Fortunately, I have already developed all of the
necessary circuitry in the COMPRESSOR design. I just need to reverse a few
things. Not sure how transparent this can be. Then again, maybe this is
something best handled in software. Still, the thought of a purely analog tube
processor might have some appeal. I can make this part of the TEN series.
Perhaps even make the effect adjustable, controlled by the IR remote. Too much
on my plate right now. But it is good to think ahead for 2009. It certainly
would be an innovative product. Do you know anyone else making such a device?
Oct 05
------
Was thinking about tube protection, for the tops of the tubes sticking out the
top of the chassis. A lot of companies now use that standoff trick with a ring
screwed to the top. Looks sort of neat. I think a simple handle pair is just
as nice. Black would be best. DigiKey has the 377-1233 that is tall enough to
protect the 6H30. Wondering if I should try something like this. Is it too
much? Silly? How can it possibly work for the 2A3?
So I found some old handles (TRUMPET stock) and set them atop the HA-10. Hey,
not bad. Had them aligned front to back. Came home from the post office and
daughter #1 had rearranged them diagonally. Wow! They form a loose "V" shape.
Looks way cool. But probably only works for the single tube chassis. The five
tube preamp might need something completely different. Anyway, something to
mull over.
Made up a new advertisement. This one will print sideways and so is unreadable
unless you turn the magazine 90 degrees. I dunno. The time pressures make me
lose my creativity. It's ok, though. I'm fine with it, considering it crosses
another item off my todo list.
World Tube Directory ad
Oct 04
------
Red. This is my new color. I did some photoshop on the anodize and came up
with a standard color match for the website. In RGB hex it is #801010. That's
webspeak (html) for R = 50%, G = 6%, B = 6%. It looks like this:
Had a crazy idea last night. Was thinking about the LC-10 and all of the
custom-built power cords and how to burn them in. Maybe I could put an RCA
jack on the box as an input to feed in a FRYBABY? Wait, what if I build a FRYK
inside?! This is a little out of the box, but what if everytime you turn off
the LC-10, a FRYK turns on and feeds a signal to all of the power cords? They
are all terminated into power transformers, so the the load will be mostly
inductive. Voltage too low to turn anything on (diodes) in the secondary. The
idea is to burn-in the power cords everytime you shut the system off. Not sure
how to extend this to RCA interconnects, but it's kinda neat. You get a
continuous burn-in signal on the power cords (all of them) when off. I'm
wondering if I can do something similar for interconnects. Maybe the LC-10
can have FRYK outputs on RCA? It would then have the capability to fry any
cable in the system. I still haven't figured out how I want to implement the
cartridge degauss and FRYK burn-in on the PL-10. I took the button off the
front, as I figured it was a mode you didn't want to accidentally engage.
Maybe a button on the back.
Measured output impedance of HA-10. Looks like it is exactly 10 ohms, but
since I added the 100 ohm damper on the 8 ohm tap, that means I get 8 ohms or
so at the 4 ohm tap to drive grados. Anyway, it goes to 20Hz at -3dB. I wish
I could get more. Similarly, that 1% distortion at high levels is higher than
I had expected. Anyway, things to think about as I consider changes for
revision number two. Mainly, it's the re-configuration of chokes I worry
about. I'm stuck right now on where to put the choke. Meanwhile, I like the
338-1141 3.3uF capacitor. That and the Hovland equivalent from AES.
Just mounted the suspect choke on wires so I could move it around. No way to
make shielding work, as it only improves the coupling between windings. So
best defense is distance and orientation. Sure enough, an orthogonal mount got
rid of all the hum. I only need about one more inch of distance. Turns out
the best spot was right in the middle between channels, behind the mains
transformer. This gave a measurable residual equal in both channels, but at
the absolute limit of audibility. I'm going to see if I can mount the choke
behind the power tranny. Then the other choke in front, sort of a sandwich.
Might have to move amplifier choke and tranny too, to make room. Anyway, it's
a whole new layout. Also going to a different fuse holder, input connector,
moving volume control, adding LED for back panel (HAGLABS only), fixing
resistor sizes, etc. Lots of little things. Bought a bunch of screws & stuff
from McMaster yesterday to try out. Yeah, gotta experiment with various
hardware to get just the right case look and fit. Still haven't gotten a good
solution to connect board ground with the screw hole for ac input connector.
Lots of tiny details to sweat. Once you get it into your hands, everything
will fit perfect and work perfect. I have to agonize through three rounds of
prototyping and debugging to get there. That's why my kits are worth every
penny.
Still need to make me a new ad for the World Tube Directory. No ideas. But I
did take this new photo showing the CASTANET in action.
HA-10
Oct 03
------
Some quick measurements to see where we stand. A little too much voltage drop
at the ac, so changed resistors. LEDs looks really nice, same amber color glow
as a tube heater. But at 1mA just a little shy. I'm going to push it up to
2mA. Forgot to add damping on output, so that 1dB rise at LF was still there
when unloaded or driving the high impedance phones. Put in a 100 ohm load to
secondary. That de-tuned the peak. There is a slight loss of volume.
Bandwidth is now super flat across the spectrum. Initial tests showed 21Hz to
139kHz for HI, and 28Hz to 140kHz for LO. Damn. That didn't go as low as I
wanted. Sure enough, it was the 1.5uF coupling cap. Added a 1uF in parallel
and response is now 20Hz LO and 15Hz HI. So design changes C10x to 3.3uF.
That will add some cost. Supply voltages pretty much came out perfect. I got
exactly 100V where I expected it. Heaters were at 6.22Vac. Not sure if I want
to bump that up yet or not.
I can hear a slight 120Hz hum in one channel. This is likely due to coupling
between the first power supply choke and the plate choke. Have to think about
this one, no easy way to orient cores orthogonally. The noisy channel measured
0.3mV noise, the good one 0.035mV. At 1kHz, distortion was 0.4% at 0.5V output
and 0.8% at 1V (that's about 10Vrms on plate). Seems a bit high, but this is
an SET. I would expect a 2nd order to dominate. And sure enough, doing a
spectrum at a very loud level (not sure how many volts this was) the plot shows
it all.
HA-10 distortion
The volume would be excruciatingly loud, but I like to measure it anyway, as it
shows what you're going to hear on loud peaks. Not fair to drop amplitude down
to 100mV and do a plot, as distortion will drop rapidly with falling signal
level. There is some easily measured residual hum at 60Hz of -80dB. I cannot
hear it, though. Anyway, the behaviour is proper when overdriven like this.
Made some DIY versions of the CASTANET panels. They are simpler without the
logo. Black anodize with white lettering. I trimmed as much cost as I could.
They come out to $39 for the front, and $32 for back. Not bad!
Oh yeah, read last night the Fast Company mag, it was all about industrial
design. That's kharma. Good tips on how the design has to be human. Or focus
on the human touch and experience. Easy to use and look at, in other words.
but they also emphasised it extends to every other function in the business.
Sales, marketing, packaging, etc. Hmmm. That means the HAGLABS wensite should
be done in red! Not that orangy red red. But the purplish deep red I got for
anodize. That color. The website has to reflect the same coloring as the
product. It will be the brand image. I need to also make navigation and
ordering reflect the way-cool remote control. Bingo! Shux, this is gonna be a
lotta work.
Here's a question, how do you combat inflation? I just bought a case of kester
63/37 solder. It's the best. And it has lead. About to become obsolete.
Wondering if I should also buy a case of PCM1704K.
Oct 02
------
And so I'm thinking of the rack. This new chassis style allows itself to be
built into a self-rack just like the CONSTRUCTOR series. Just add wood planks,
bolt directly into the chassis. Simple, cheap, and works with vibrational
damping (I suggest maple).
CONSTRUCTOR rack
Thinking maybe something slightly more fancy. What if I add small brackets in
between the wood and the chassis? It provides a wider and more stable
footprint. And it might look kinda cool. I could just have a hook which fits
into one of the vents, although that depends too much on gravity. I prefer the
direct bolting method.
And so why not do more to make a complete system? Seven stacked boxes, $27k.
Built-in rack. Not only will it look fabulous, but it will be very practical
too. So why not take this a step further? What if I make custom power cords
that are each the perfect length? This will greatly reduce cable traffic and
overhang out the back of the rack. Why not clean it up? Similarly, I should
offer interconnects that are cut perfectly. I'm signing up as a Cardas oem, so
I have access to jacks and posts, might as well use the wire too. You may
laugh at the concept, but methinks there are a lot of luxury audio buyers out
there who truly care about appearance and how equipment melds into a living
space. Eliminating cable loops and excess wire has to be a step in the right
direction. Not every installation can accommodate equipment sprawl.
It's the WAF. Yup, that's the paradigm for making the sale. The wife has to
say, "oh, that's cute!". Remember, it's what they don't tell you that counts.
The perfect examples are audio mag ads. Every time you see an audio rack or
speakers in a living room photo, what is missing? Cables! The damn machines
are NEVER plugged in. We need to fix that. We need to make systems with WAF.
Ok, just unpacked my new HD600s. First thoughts, wow, they are comfortable! I
could wear these all day. Second, the bass is tremendous. I like it better
than the Grados. However, the top end of the Sennheisers seems to be a bit
muffled and rolled off. Maybe they need some break-in.
Tada. Fired up the HA-10. Finally. Have been super busy with production and
filling current orders. Also got the missing parts in. Sometimes, with a new
machine you have to be really careful powering it up the first time. The
probability for smoke is quite high. Who knows if I routed the traces where
they should be (it was all done manually). So, bring it up one section at a
time. Nah. Just plug it in and see what happens. If it flames, then I know
exactly where to look for a problem. Anyway, it came up ok. No issues. Ran
right off the bat. One gross mistake, I connected the wrong side of the
headphone jack on the LO side. Duh. Bunch of changes to make for next rev.
Sounds just fine with both headphones. With the HD600 I get super black
backgrounds. For some reason, one channel in the Grados gives me a slight
120Hz hum. I think the louder of the two chokes is next to that tranny. Not
sure why I don't hear it with the other phones. So it is up and running. I
can start to run some measurements tomorrow.
Oct 01
------
Where can I get a tiny bottle of yellow paint? I ask myself. The answer is at
an automotive shop (but I never figured it out). Instead, I went to the drug
store, thinking about my teens when I built plastic models and used Testor's
paint. Nada. Not in this store. However, for some reason I find myself with
the nail polish aisle right in front of me (no jokes, please). Bingo, there is
a jar of yellow nail polish for one buck! Sad to say, it didn't color the
letters on the panel, which was the entire point of the experiment. Ok, so try
a yellow higlighter. That actually did something. I could see some yellow.
And I be damned, it actually looked right. The yellow letters were a perfect
match with the red anodize. I never would have guessed. Had ordered the LC-10
panels with black letters, because that was my original preference. Ok ok, next
proto sample gets yellow. Like my wife said, "if you don't go with the yellow,
it proves to me you have no balls." I kid you not. Maybe I paraphrase a bit.
Tomorrow I pick up the HD600s.
Today I put in some NOS tubes into a CHIME GOLD. Seems the folks at Lowther
America needed a USB2SPDIF connection for their room at RMAF. And they kindly
asked me for one. I talked 'em into a CHIME instead. It's running in right
now. Man, every time I hear one of these things I am just floored. The sonics
are completely different from what you get out of a HAGUSB (DAC portion). It
really is superb. My longest listening sessions end up being with a CHIME.
Sep 28
------
I designed front and back panels for everything in the TEN series. Started
layout of the PL-10A boards, including the CPU card, that fits on the panel.
The amplifier box ends up having two boards, one normal with all of the tube
stuff, and then the CPU board fitted orthogonally. I connect the two with a
pair of 2x10 headers (gold pins and sockets, of course). This keeps the
digital separate from the audio. The controller runs the remote, DAC, LEDs,
etc. Plenty of control signals between boards, maybe 20 of them. Select lines
for relays, DAC control lines for volume, balance, and loading, etc. So things
keep changing as I get to see how everything fits together.
I found some bad interferences in the PA-10, between the binding posts and
choke. Input connector wiring too close to rectifier wiring. That sort of
stuff. Would be so much easier (and better electrically) if I could put the
input and output jacks on the front panel. Anyway, moving everything around
such that there is coherence and synergy through the line. RCAs move left,
umbilical moves. I change RCAs to wire type so as I can place them visually
centered on the power cord, etc. Now using two pair of binding posts on the
power amp. One wired for 8 ohms, the other for 4 ohms. In fact, you can use
both outputs at the same time (bi-wiring). It's cool and flexible. LEDs are
in same spots for each machine.
And then I'm thinking. Hey, for the DA-10 I can do the same dual-board trick
as in the PL-10A. Only problem is that I have to run audio through an extra
set of connectors. But wait, there's more. I realize that maybe I should just
use the HAGDAC! Shoot, it's the best friggin converter out there. It uses the
best parts. And it already exists. It would save me so much time. There's
more. By going to the HAGDAC the I2S interface is lost (now I only need one
signal tranny instead of three), but I gain something hugely important from
the PCM2707 chip. I get pushbutton controls! Yes, not only can I add play,
stop, previous, and next buttons on the panel, but I can put them on an IR
remote control. Yes, now that is both different and worthy. Imagine having
the standard CD transport controls at your fingertips, yet for a USB input!
The PC can now be controlled via your chair. In fact, I can combine the
remote buttons with the remote for the PL-10. One remote controls both boxes.
It is all seamless to the user. Shove a CD into the PC, sit down. You can now
pause and skip tracks from where you sit. A remote controlled DAC. Yes, that
is not only awesome, but I save many months of development time by using the
HAGDAC. Hmmm, I can even add both filter and phase buttons while I'm at it.
Ok, forget it. No buttons. I thought about it and decided to use the new
style remote control. Not quite as straightforward, but I think can work
pretty well. It will be more like a shuttle knob. Turn one click right to
play, two to skip a track. One click left is pause. Two, previous track.
Keep clicking to skip more tracks. Then, like switching modes on the preamp,
you can change both phase and filter rolloff. I can then add buttons on the
remote to select between preamp and DAC (but only if you buy both machines).
Normally, each machine will come with it's own separate hard-coded remote.
Hey, I just realized there is only one more VACUTRACE to go. Then I am out of
chassis. If I could get another ten from Hammond I would. But they have a
minimum order of 25 for custom work. In a way, I'll be glad not to have to
build any more of these, they're a ton of work.
Ok, so I made up a graphic showing all of the panels. This is what the rack
would look like from both front and back. Of course, there are tubes sticking
out the top of each box, so in reality the spacing is greater.
Series 10
From the bottom, we have the line conditioner. One power switch on front fires
up the entire rack (each piece has an additional pushbutton power switch on
back, which can be left on). Next up is the power amp. It is a monoblock,
not mirrored (both channels look the same). Four binding posts for bi-wiring
or choice of 4/8 ohms. Then the headphone amp, volume knob not shown. Fourth
from bottom is the usb dac. Top two boxes are the phono/line preamp, power
supply in separate box. It has two phono and three line inputs. All remote
controlled. Overall these boxes are really small, about 10" wide by 4" tall
and only 10" deep. You'll also be able to rack them vertically in a tiny
footprint, just like the old CONSTRUCTOR series. These are not cheap
components, but the best of the best. The choicest parts and fabulous circuit
topologies. One full stereo rack will probably retail for about $27k.
Basically, you can buy an entire rack of electronics (with remote control) for
the price of one Boulder solid-state phonostage.
Sep 27
------
Reading Fortune magazine last night and come across this quote. "With global
millionaires doubling since 1996, there's been a surge in demand for luxury
goods." Hmmm. I wonder if that applies to the hi-end market. Will it
continue? Is hi-end a luxury? I'm wondering how an upcoming recession
(predicted by some) will affect the industry. And how will I be affected?
Well, the first thing to realize is that the existing wealth will not be
destroyed, merely redistributed amongst participants. That is, the rich will
get richer and the middle class poorer. Those holding paper dollars will lose,
those with gold will win. So my guess here is that the middle class will stop
buying hi-end, and the elite class will actually be able to buy more. Oddly,
that's the two markets I should be in. Those caught in deflation will only be
able to afford DIY kits, as a means to hi-end. I do that. Then, aim the
HAGLABS equipment to appeal the luxury market. And it seems to me even with a
recession the number of billionaires will still go up. I need to position my
marketing at those who don't think about price, but care only of features,
quality, and sonics. Sales of mid-tier equipment ($1k to $3k) will likely
suffer the most. Chinese-made goods will do fine, perhaps dramatically
increasing market share. But hey, I'm only guessing.
Designing the PL-10 power supply, I planned to shove out +/-5V into the preamp
box and then burn power down to +/-3.15V. Well, shoot, that turns out to be a
lot of power at 3 amps. If I move the dissipation back into the power supply
box (good), then I need more contacts on the umbilical. Well shux. I only
needed that extra set of supplies if I'm going to do a JFET buffered tap outout
and/or PICCOLO style mc headamp. And here's what happened. Realizing the line
voltage varies by 10%, I did not have the margin to do an LDO to +/-5V. It
would drop out. Without the regulation, the mc headamp would likely amplify
too much 120Hz residual power supply noise. It only takes a microvolt. Going
to +/-4V supplies just isn't going to cut it. Not enough headroom. We can't
allow any of these circuits to clip. Not at these prices. I tried borrowing
the passive regulation scheme from the TRUMPET, but it's only good for about
20dB to 30dB rejection. It is a trick I finally reveal now.
MC headamp
This is basically the front-end of a PICCOLO. The supplies are made from
rectified tranny, no regulator. So even with much filtering you still have
residual 120Hz noise. That noise is on the +5V supply and feeds directly to
the output. As the JFETs act like pentodes, they are high impedance devices
and so the PSRR is zero. The trick is to cancel it out. If the filtering is
symmetrical for both positive and negative supplies, then you have essentially
an equal and opposite noise waveform on the -5V supply. This feeds the current
sink tail on the differential amplifier. It is important to note that the
JFETs bias with cathodes roughly at zero volts (it's really a little positive).
The cancellation is only half! Any noise on -5V creates a current through the
6.6k resistors, which then convert to voltage again across the 3.3k outputs.
This ends up being a voltage divider, you only get a 6dB cancellation of power
supply ripple. The trick is to add that big cap. Yeah, that's the 10uF in the
TRUMPET schematic you could never figure out. What happens is that the supply
noise is bypassed by the cap such that the tail becomes 3.3k. Hence, you get a
perfect 1:1 elimination of supply noise. In practice, it's not perfect, but is
suprisingly good. The output voltage remains stable, even as the supplies
shift around. Passive regulation. Simple. Beautiful. The output on a
TRUMPET stays put, whereas that of a CORNET moves with the ac supply.
Nonetheless, for an MC level input this is never going to be good enough. So
my new plan is to just scrap the JFETs. Remove them all from the PL-10. MM
phono input is MM only. Tape output is unbuffered. Now I can go back to four
pins on the umbilical. Save heat, make layout easier. Make all of the low
voltage stuff in the amplifier work from +/-3.15V.
Sep 26
------
Bought a fine pice of laser carved koa to cover up the unused headphone jack in
the CYMBAL GOLD I built (it's up for sale), and the sales lady asked, do you
need a bag? I almost always answer, nah, save the planet. And then I realized
maybe I can do more with HAGTECH to be green. Earth friendly, that is.
Already we've instituted a number of processes that are pretty reasonable.
1) We use our shredder non-stop, grinding up credit card solicitations, all
the junk mail, envelopes, old schematics. Everything. This paper mulch then
becomes cushioning material for our packaging. We do not buy packing peanuts!
Sorry if it is a little messy.
2) We re-use all boxes from Mouser, DigiKey, and others. The products you buy
do not show up in fancy HAGTECH boxes. They come in recycled and used boxes.
Ok, it doesn't look so professional. We even save and re-use all peanuts and
other packing materials.
3) We recycle all audio magazines and catalogs. All paper goods get sent back
to local recyclers.
4) We use small padded envelopes to ship most items. Minimal size and weight.
5) All electronic parts nowadays are pretty much lead-free. We even use a mix
a leaded and lead-free solders. Why leaded? Well, because of dendrites. You
see, unleaded solders are designed to fail over time, as they form tin whiskers
that end up shorting to nearby pins. Therefore, on surface mount parts and
anything with small lead spacing, we use lead. Why? Because we want our
machines to last forever. We do not promote obsolescence. Every item is built
to heirloom quality and is expected to last dozens of years. We don't expect
you to throw them away, but re-sell. These machines retain value.
6) We combine as many items as possible when ordering parts. We delay product
shipments to accommodate combining part orders. This results in fewer shipments,
less packing material, and less waste.
7) Our shop is small and efficient. We use fluorescent lighting. Soldering
irons are never left on.
8) We use the internet and email as much as possible.
9) Each car trip is a pre-planned exercise in routing efficiency, trying to
hit as many stops along the way. No separate road trips just to get toner or
whatever.
That's a start. Right now I think our biggest waste is the plastic packaging
that comes from DigiKey and Mouser. They bag each item individually! We throw
out a lot of plastic. And I don't know what to do about it. Any ideas?
Ok, just designed the power supply for PL-10. Yeah, I had it outlined, but now
that I add up the load, oops. I need 3.1 amps of heater current! So running
through the numbers, I end up with four 155B chokes and twelve 10,000uF caps
just for the heaters. But hey, it gives me +/-5.1V, which I can use for JFET
circuits and regulate down to +/-2.5V for CPU circuits. And the ripple is only
6mV at 120Hz. No wonder nobody else does heaters like this. The B+ was a bit
more normal, with two 157J chokes and seven 100uF 450V caps for +260V at 55mA.
The whole concept is scalable to use for the DA-10 box. Anyway, I can start
layout for the power supply board and chassis. It'll look something like this.
PL-10 power supply layout
Sep 25
------
Looking for some decent binding posts. Not happy with the normal crap. I like
those heavy-duty types I see on some speakers, they have giant knob cranks.
Any idea where I get these?
That new spray paint worked wonders on the UFO. It looks fabulaous. The paint
is "appliance enamel" from rustoleum. They make about fifty different spray
paints, this is the one that works. Spend a few extra bucks. And then another
benefit occurred. I painted from a side angle, to get the rims nice. It ended
up leaving the drilled strobe holes semi-unpainted, and they reflect the blue
LED light quite nicely. I don't have to find a way to fill them in with
something white. Bingo. I can finish these off. They'll sell if people can
actually see them.
Ok, so that red HA-10 is really starting to sink in. I am getting used to it.
Still not sure about the oversize panel. It's super nice from straight on.
From an dangle it's not the best. Ask my wife (the designer) what she likes,
and after some time she says the back. Do the inside panel. But make it
flush, not recessed. Ok. I can do that. But I'm not yet sold on the yellow
ink. I made a mistake having them built with white ink, she said yellow. Ok,
the LEDs are also yellow. That might work out. On the other hand, I am really
leaning on black letters. The red anodize came out much brighter than expected
and I think the black will be very classy and subdued. Do I really want this
chassis to shout? Also looking into designer LEDs that will be a small 2mm or
3mm round flat face (non-protruding) flush with the panel. Make it look more
expensive. Yeah, tomorrow I order the LC-10 panels with black ink. Maybe I
can use a highlighter and fill in the HA-10 panels myself with that color, just
to get a look at it.
Sep 24
------
Didn't sleep well last night, not sure why. Maybe it was the waffles for
dinner. Anyway, 3am I'm wondering what to do with my leftover UFO parts, and
shazam, I realize I can paint them black! The top two pieces have this horrid
hard anodize that is insane to try and remove (which I used to do), to get a
nice metallic color. Well shoot, why not just paint the thing gloss black and
see what it looks like. Make the strobe holes white, not black. Just reverse
the whole design. So I am trying it out. Been experimenting with various
spray paints to find one that results in a hard non-scratching surface. This
attempt is with appliance enamel. Most importantly, I can bring a cool new
fangled UFO to RMAF.
Got most of HA-10 and PA-10 built. Realize I am still short parts. Ordering
more from mouser today. No ac input jacks, so I can't even plug the dang thing
in. A few component fit issues, but mostly they are coming together well. I
have two weeks to crank these out.
And so the panels came in. Built up the HA-10 for appearances, to get a good
look at it.
HA-10 frontHA-10 rear
Not sure I like it. You know, the smaller panel inside the shroud on rear has
a cleaner and nicer appearance. So much for copying the industry. The red is
pretty bright. I think I'll order panels for the LC-10 in another color, just
to compare. Maybe if both front and rear were shrouded? That would be unique.
There are some fit issues, but you get the idea.
Maybe the lettering needs to be black. At least the logo is bitchin.
Sep 22
------
Last night the internet dies. Well, not really. Turns out the DSL modem slash
router died. We've been experiencing blackouts quite often lately. And then I
noticed is was making a hissing noise. Yeah, I knew something was wrong. Ok,
I open it up and find a blown electrolytic. Probably the filter capacitor on
the dc input. I could see it was feeding into a dc-dc inductive switcher. Ha!
Who better to have such parts and a soldering iron laying around? I took the
closest cap I had, from the BUGLE power supply (4700uF 25V) and swapped it for
the blown one. Tada. Nothing but net.
Speaking of technology, I was in the apple store last night. Can they possibly
get any more illumination in there? Anyway, looking over the fine hardware and
notice the uber-box. It's an all-aluminum chassis, and with one white LED for
power. But they way they did it was cool. The LED was behind a tiny hole in
the faceplate. It looked really nice. Damn, that is something I can use.
Maybe I should do something similar for the HAGLABS stuff. Been poking around
with various panel mount LED styles, nothing is a winner so far. This concept
might just do it. Although I would use a larger hole, as the LEDs need to be
visible from across the room. Then I notice their new keybaord. Wow. Way
simple. So elegant and small. Radically plain and clean design. Superb. It
even typed well. That's the effect I need to achieve. Clean lines, nothing
extra, noting wasted, in complete touch with the human. Super user-friendly.
That is seriously good product design. I felt like bowing.
Sep 21
------
Got the PA-10 proto board in last night. Will start to assemble. Many parts
not here yet, though. Re-thinking the PL-10 and the degauss function. Decided
I don't want it activiated by mistake, so removing it from front panel display.
Instead, I'm putting back in the mono function. On the rear panel, I will add
a pushbutton that will temporarily put the machine into degauss mode. Not sure
if I want to make the sequence automatic or manual, because it does way more
than just degauss an MC cart. It can also do self burn-in of the machine and
of any cables connected to it. Built-in FRYKLEANER. My idea (at the moment)
is to enter degauss mode at zero volume. The use then turns the control clock-
wise for maximal amplitude, wait 1/2 a minute, then turn down slowly to zero.
This is a perfect de-magnetizing cycle for MC carts. However, I can add a mode
where the MC input is disconnected and the signal then feeds the phonostage and
linestage sections, causing a self-burn. Even better is that it does the
output interconnects. This is a handy feature, but best relegated to a
maintenence mode, not something you can normally get to with a remote control.
Besides, any ultra phonostage needs a mono switch.
Hey, you know those asian grilled chicken salads from mcdonalds? They're
incredible for $5. You can actually get me to eat health food.
Ok, got some photos here of the start of the PA-10 build. Top shows the output
tranny mounted to center of pcb. Bottom has transformers and choke. I love
all this iron in a machine. Wondering if the heat sinks are two small. They
have to dissipate 2W for biasing the 2A3. Theoretically it will be ok. I
never took the time to calculate how hot they will get. Will do the old
calibrated finger test.
PA-10 topPA-10 bottom
Made lot of progress this week. Again. So I'm going to try and keep up the
momentum. Just have to impose deadlines on myself. Like having working PA-10
and HA-10 protos at RMAF. Then get the HA-10 half-kit (CASTANET) out for
Christmas buying season. Added some new ones today. Get proto LC-10 built in
a few weeks. Do schematic for analog section of PL-10. Design and build power
supply box for PL-10 before end of year. Try out various aesthetic panels for
the TEN series and decide soon. Design JFET sections for +/-5V supplies next
week. This is for SS headamp and tape out buffer (yes, add them back in).
Why? Because these are features I would want. I want the tape out to feed the
headphone amp, the mono switch for listening. It is more circuitry and cost,
but I want them. That keeps me real busy for the rest of 2007. And I should
be able to launch HAGLABS PA-10, HA-10, and LC-10 to production in January.
First part of 2008 will be for digital design, software, and remote control for
PL-10. At that rate, I should be able to put on a full room at RMAF08.
Sep 20
------
Sometimes I just miss the obvious. So often the clear-cut simple choice is
there right in front of my face and I can't see it. My brain is off wandering
in all other directions coming up with obscure and unusual solutions. With the
LC-10 line conditioner I was doing just that. Really wanted to force fit this
thing onto a circuit board so it would be just like the other machines in the
line. Stupid. It was causing problems and adding a lot of cost. Also a lot
more work. Duh, just don't use a circuit board. Hard wire up the trannys and
switch and outlets. What is so hard about that? Not having a board leaves way
more room. Anyway, that's where I'm headed. Discovered this fabulous line
filter from mouser (592-6eq8) that does everything I wanted. This is WAY more
than your typical $10 filter. In fact, it goes for almost $60. Not exactly
the way to get costs down, but hey, I'm aiming for performance here. Need to
buy the main parts. I think I'll build a proto with only two trannys to start
out with. That way I can test the design before committing too much cash. The
good news is that cost came down, and if I take a hit on my cut then it should
retail for $2000. Competitive with a power plant, but without the feedback
loop. The one drawback is the output is limited to 500W max for all outlets
combined. Otherwise, each can deliver 100W. That's ok, as that should be able
to supply power to a full rack of TEN series machines. Plus CD, FM, DVD.
Sep 18
------
So I step back for a minute and look at the TEN series. Is this the right
thing? I think so. Started making a brochure for it, sort of a full-page ad
that will have a photo of the HA-10, and then drawings of the entire line.
This I can show to people (dealers, distributors, customers) for feedback. See
if them guys at RMAF like the concept. If I need to change it, now is the
time. And so I look at pricing. If selling via retail shops, they get a big
cut, so I have to use something like a 4x or 5x multiplier above raw part cost
to get a estimated MSRP. Pricing in the end will depend on perceived value,
desire, labor costs, inventory, etc. Anyway, I come up with ballpark pricing
of $8k for the phono/linestage (two box), $5k per 6W monoblock, and $2k for the
headphone amp. That's pretty reasonable, especially when stacked up against
the competition. Many of the boutique manufacturers charge double this for
similar items.
I figure I have a real good headstart on the headphone and power amps. They
will obviously be done first. I'm thinking I can add the line conditioner too
without too much effort. Drew up my concept of the four transformer / eight
outlet design. Heavy and very compact. Two line filters, fuses for each
output. I think I'll use two power switches (one for each bank). Can then
run some extra isolation between left/right banks. Put a 115V/230V select
switch on the inside, some LEDs indicating each outlet that is on (goes off
with blown fuse). Chassis and appearance all same as line. This will be a
very heavy box. But I add up the pricing. Wow, $600 in raw parts. Son of a
gun. That translates into maybe a $3k retail. Seems pricey to me. Then
again, it should offer good performance with the line. And if you're going
to fork over $18k in preamp/power amp, then another $3k ain't no big deal.
Shoot, you might as well get the headphone amp too. Buy the USB DAC later.
Let's see. Maybe $25k total? Six boxes, 18 tubes, zero feedback.
Wow, I'm not sure I want to fork over $600 to build me a proto line filter
right now. Ah, what the heck.
Let me set some new short term goals here. The HA-10 and PA-10 protos will be
up and running at RMAF. I will have CASTANET ready for sale before Christmas
(must order production boards when I get back from RMAF!). Have LF-10 proto
built by end of year. Schematic for analog sections of PL-10 done by end of
year, design digital section first thing next year. Starting 2008, HA-10 and
PA-10 go on sale at HAGLABS.com website. Ramp up will be slow, giving me
plenty of time to finish PL-10 design. It has to be ready for RMAF08 launch.
Maybe I can also have a proto of the DA-10 by then. At RMAF08 I should be
ready to announce distribution / dealer networks. Thus is the plan.
Meanwhile, I think I'll sell off some more stuff on audiogon. My lovely
personal custom GOLD CYMBAL can go. I don't need it anymore once I make the
PA-10. I can also sell off a line filter that matches the CORNET2 chassis
(but silver), a FRYPRO2, the CLARION. Not sure if I have time before RMAF.
Sep 17
------
Painted all weekend again. About half-way done.
Bought tons more parts today. Stuff needed to finish both the HA-10 and PA-10.
I will bring both to RMAF. Curious how you folks will react to the color
scheme. Right now I have to wait several days before I can solder these fine
boards. The PA-10 should be here tomorrow, though.
Getting tons of HAGUSB orders. And I think it is all from the 6moons article.
This is the biggest bump in sales I have ever had due to a review. Well, at
least since Fremer did the TRUMPET.
Sep 14
------
And so I see folks at audiogon want switching between two MC carts. My PL-10
switches between an MC and MM. Had earlier thought about adding a PICCOLO
circuit in there. Well, maybe I should. I re-thought the topology and think I
can add a PICCOLO 20dB gain section to the MM input. The price is that I would
need two variable resistance netwroks. One for each input. That's ok, in a
way a benefit sonically. The relay switching is then only to feed the actual
phono section, loading is soldered tight. Anyway, the result is an MC input
with 60dB or 66dB, MM with 40dB or 60dB. Or something like that. Loading on
the MC can probably go down to 20 ohms or so, the MM only down to maybe 500.
You also get your choice of tranny or JFET step-up. I still need to see if the
+/-5V supplies give enough headroom. The positive rail might need to be
higher. Something to look at when the time comes.
Oh, our kolea showed up yesterday (golden plover). Been gone since May. They
migrate to Alaska for the summer. This one is lazy, usually one of the last to
go and last to return. But he looks good, considering the flight path.
Finally. Got me that power amp layout done. Lots of schematic changes, not
just the CCS replacing the choke. Also grid resistors, etc. Took forever, but
I got the symmetry and tracing I wanted. Very three dimensional, as there are
big and tall parts on both top and bottom of board. Trannys on bottom, tubes
on top, caps on both sides. I use the ground plane as a shield to hide things
from one another. We'll see what happens when I build it. Usually some huge
mistake pops up, some nasty mechanical interference I didn't see.
PA-10 layout topPA-10 layout bottom
On top of all this, the hard drive is starting to crash. I almost lost four
hours of this mornings work. As it was, an auto-backup feature saved all but
the last half hour. Working on backups, etc. Cleaning up disk. I hate
spending time doing such.
Bingo! The CASTANET circuit boards just came in. I can already identify a few
mistakes. But mostly, it looks real good. Fit is almost perfect into chassis.
The front panel hole position for the headphone jacks will be slightly off,
though. Need to order lots of parts (digikey, mouser, aes, etc.).
CASTANET topCASTANET bottom of board
Sep 13
------
Making great progress on the PA-10 layout. Agonizing, though. Easy to fit all
of the pieces, but to make it work properly is killing me. Trying to untwist
traces, keep current flow where I want it, long/short runs, voltage spacing,
shielding, are making it quite the puzzle. I am spending hour after hour just
moving about 5 capacitors. Trying hundreds of variations. In fact, I ended up
just 0.1" shy of being able to fit the 30H choke where I wanted it, you know,
in a symmetrical spot to cancel any residual fields. Shoot, I just took it
out. Yep, I'm changing to a CCS load for the driver stage now. Heck, it will
likely work better anyway, especially in the deep bass. I hadn't realized I
have tons of spare supply voltage to do this, which wasn't available in the
HA-10. Got rid of that choke, turned the socket around and voila! A new
solution that cleans up a lot of routing. I had way too many signals crossed.
Also, adding film bypass caps across all of the signal electrolytics is causing
a headache too. I am most of the way there now. When you see the result, it
will appear to be so simple and clean. You'll ask, "is that all there is?"
because everything fits just perfect. It will be very clean. You just won't
realize how many hours of jigsaw puzzle manipulations I had to go through to
get there. At this rate, it's about one hour per capacitor. That's what it
takes to create art.
Ok, just ripped a bunch of stuff up (traces, that is). Redesigning the CCS so
that parts and ground currents make sense. Anal about symmetry. Moving all
ground points closer together. Keeping loops small. Having hard time with LED
spots, as they don't want to be anywhere near where they should be. That's ok,
I got wires. But they're only 6 inches long, so I still have to be careful.
New CCS looks good, fitting in much better. Schematic changed quite a bit.
That's the way it is when I design. Big feedback loops. I don't like what I
see in layout, then I go back and change the schematic. Or maybe I change the
requirement. Increment around and around in circles until everything meshes
with synergy. It's the only way to design. Holistic. I cringe when I see the
typical engineer design a circuit and then throw it over the wall to some other
guy to lay it out, then another to build it. What a mess. The way I do it,
after proto build and debug, I send all the information back to myself. Then
I update everything needed for next revision. It always takes a few tries to
get it just right.
This one is way more work than the CASTANET was.
Sep 12
------
Started drawing schematic for PA-10 and dang! I messed up. The power supply
was designed around a single 2A3 tube. Running through all the numbers and
this will not add up. Cannot use the 22772 tranny. The famous 273DZ will
work, and I have one on hand. But it doesn't fit inside chassis. My plan of
jamming in all trannies inside box ain't gonna work. Not with this machine
anyway. No combination of parts will do it. But hey, I can top mount the
273DZ and it won't look too bad. Has a nice bell I can paint. I wonder if I
can get same grey color as the chassis.
Anyway, redesigned the supply. Drew it up. Try to make as simple and classic
as possible, but of course, with the CCS. Yes, this is the Hagerman Self-
Balancing Output Stage. For B+, I create a psuedo-center tap for 5V winding by
the two 100 ohm resistor. Might get rid of that, depends on what I end up with
for a rectifier. Simple LC supply with 0.2V ac ripple. That may sound like a
lot, but the PP output stage rejects it, so I don't need an extra choke. The
124B offers the CM rejection. Input/driver stage is single-ended parafeed into
the 124B. It splits phases and adds a little gain (1.5x). Decided to use a
zener for CCS as this doesn't need to be super high performance. No need for
compliance or PSRR. Just a very simple passive and matched pair of CCS.
Pretty sure I can get 6W of very low distortion and low output impedance from
this circuit.
PA-10 schematic page 1PA-10 schematic page 2
Perfect dc cancellation in the core. No bias adjustments necessary.
Sep 11
------
Ok, so I just spent a few bux. Bought front and rear proto panels for the
HA-10, and a circuit board. I should have this thing up and running in about
two weeks. Plenty of time before the RMAF show, which I just bought a $550
plane ticket for and $180 worth of hotel room. I fly Thursday night redeye, so
get in about noon on Friday, just when the show starts. Leave first thing on
Sunday. This causes minimal impact on the family.
Just had a thought. If I jam it, I can have the design for the power amp done
by the end of this week. Why not? The big project is the phono/line stage,
but it will take a long time. Meanwhile, if I just go with what I have, this
PA-10 can be done & proto'ed before RMAF. Hmmm. It's just money. Wonder if
I should build a pair or just one? I think I will do it. Then again, I'm
still re-thinking whether or not to make the driver stage single-ended or PP
same as output.
Sep 10
------
Finished up the layout for CASTANET (HA-10). Also made the front and back
panels. Just checking out final tweaks. Maybe I order stuff tomorrow. Adding
an internal fuse. Tons of space leftover on this board. That will come in
handy for more complicated designs, like the DAC. Still haven't quite figured
how I want to ground the chassis. Think I can use one of the screws that mount
the ac input connector to the back panel. Jumper that to the earth grouns lug.
Discovered the maximum panel thickness for red is only 3mm. Might be way too
skinny. Anyway, it'll get me into production. If product takes off, then I
can invest in custom made thick panels in bulk. Easy retrofit.
Sep 08
------
You know, I am just not getting this dynavector tuned in. It is not working on
my P3. VTA is a mess. It sounds thin. Just can't dial it in. I might go
back to the goldring MM, which sounded fantastic. That was a nice combination.
So while I'm at it, when I shop for new speakers at RMAF, I may as well check
out tables. Actually, it's the arm. I must have adjustable VTA in my next
arm! Probably end up with a galibier, but for now I will keep an open mind.
Found an interference in the layout with the power switch. Investigated a
bunch of alternatives. I can't believe it, I ended up using the same switch as
in the OBOE. Never would have predicted that. It is a pushbutton! But I
think it will work, from both user-friendly and visual or industrial design
standpoints. It has a very good positive feel, and I can make the cap match
the lettering color. Oh, here's a photo of the compromise anodize.
New panel coloring?
Oh wait! This just in. I ask the wife if the medium bronze is ok, since the
dark is not available (from FPE). Nah. Now she says try the red with white
lettering. It really stands out, something different. And now yellow LEDs.
New panel coloring!
Actually, I like the medium bronze. Maybe I should make one of each. Still on
schedule to bring an HA-10 to RMAF. We'll see what the real customers have to
say.
Sep 07
------
Actually, what I should do is make the driver stage to that amplifier look just
like the output stage. Repeat the self-balancing, harmonically-nulled stage as
a driver. Maybe a 6H30? Then I can get rid of plate choke. Just need to find
me a decent PP interstage tranny. LL1671PP?
Finally mot me some momentum going here. Did the schematic today. Should be
able to have layout done next week. Design is coming out exactly as I had
hoped. Very classic and simple. Yet with a few modern touches. R1, R2 burn
off power to drop line voltage from 120V to 115V, which makes the transformer
much happier. It will run quieter and cooler. C1 removes RF hash from line.
R1, R2 also act as fuses. D3, D4 are ultrafast soft-switching diodes. LCLC
supply, produces a very quiet 100V with a power factor near one. R3, R4 set
common mode voltage for heater, which is 6.3Vac about ground. R5, R6 drop
voltage to tune for exact heater voltage on tube. They also provide a bit of
soft start. C2, C3 remove RF hash to ground. D2 indicates LO (heater) supply,
D5 HI (B+) supply. Both come up fast with B+ overshooting to 150V until 6H30
warms up. This is low enough in voltage so as not to cause cathode stripping.
L3 is plate choke, so 6H30 runs constant current in parallel with reflected
load line. Output voltage has huge headroom. 119DA is not drawn correctly.
I'm lazy and didn't want to draw a new symbol.
HA-10 (CASTANET) schematic
Gack, just noticed that I have both headphone jacks and LEDs on bottom of board
in same spot. Gonna have to do LEDs on wires, I guess.
Sep 06
------
And then I had another brain fart. Looking at the LL1663 as a possible output
tranny for the power amp, trying to visualize how it might mount, when I
realized (duh) that I can do the same with the 1615. Just remove the damn
bells! Shoot, same for the power transformers. I can fit these inside chassis
by removing bells and mounting to circuit board like I did in the TRUMPET. In
fact, the 370BX has exactly the same size core and bells as the 22772. The
bonus is that I now get my 240Vac operation back. Almost for free. And a much
wider selection of trannys. However, there is no free lunch. A lot of board
space gets eaten up, plus, there is now a mechanical coupling between iron and
tube sockets. Last thing we need is 120Hz acoustic feedthrough. I need to
measure the external magnetic fields of these tranny, see if there is much
difference with the bells removed.
The more I think about it, the more I'm convinced I am right. About the
harmonic balancing of the output stage, that is. It's that resistor R? that
sets the null. You see, if that R is a large value (infinity), then the tubes
operate in series (differential mode). If R is zero, then they operate in
parallel. Basically two SET strapped together. Look at this simply, say the
triodes have 2nd order distortion in SE mode. When you do a differential
circuit, this changes to 3rd order. Even order harmonics cancel. Well what
if you make a tradeoff somewhere between these two modes? You will get a
distortion null. I'm not sure how deep it is, perhaps only 6dB. But in effect
you get double the power and half the distortion. Maybe it works even better
than this?
Finally started doing some layouts. Once begun, half done. Been holding out
on this for too long. Trying to see if everything can fit, including the
horizontally mounted 1615 and 370BX bell-less trannies. The CASTANET turned
out to be pretty easy. The chassis looks really small, but this is 86 square
inches of real estate. Same total area as in a CLARINET. The power amp is
going to be the problem. Even though it is a monoblock, we're fitting a 5AR4,
two 2A3, and one 7788. Plus three power tranny, two choke, and an interstage
tranny. Yikes. Fortunately, I have both side of board to mount things on.
The iron and big caps on bottom, signal caps, resistors, and sockets on top.
Anyway, while fitting, I realize the 124A tranny can work, but only in
parafeed. Duh, the measurements went way deep into the bass if there was no dc
current. So just use the 157G 30H choke in parafeed. This arrangement worked
great in the CASTANET. That could be a solution! And maybe the 124A is better
than the 124B? Ok, so I add a choke. Very tight fit, but I think this can
work.
HA-10 (CASTANET) layout
You'll note I made the board symmetrical. That way I can build either a left
or right channel, depending on what gets stuffed. There is only one 8-pin
socket used for a rectifier. Only one ac input, etc. Output tranny has to be
rotated 90 degrees from power tranny to prevent magnetic coupling.
PA-10 layout
Just realized I have no ground connection between board and chassis. Hmmm.
How shall I do such? I'm pretty excited about this amplifier. Sure, it'll
cost an arm and a leg, but it could just be some of the best 6 watts out there.
If this distortion cancellation trick works, I get a big advantage over every
other design. And if the 124A doesn't shine, I just use a lundahl. Topology
is everything. You can throw parts at it later.
One cool thing, my laser printer has cleaned itself up over time. And I just
put in a new toner cartrdige. Bingo, no more smudges or toner dots. Printing
like it is new again.
Looking at hammond trannys, none of them will work for power supply except the
infamous 273DZ. But it is slightly too large. And it only comes in 120Vac.
So shoot, I'm back to the 22772 now. Moving connectors, controls and labelling
around in CAD, trying to get a nice aesthetic appearance. Even shifting things
a half inch can change the visuals. Simplifying to the max. Getting rid of
everything that isn't mandatory. Moved the LED on front farther apart. Head
phone jacks too. Didn't expect that, but it is nicer. Added LEDs on back to
indicate which input is selected. Also added labelling both above and below
the connector. This is so you can tell what is going on when trying to plug
things in. You'll know if you have the right input selected. The question is
where to put the words HAGERMAN AUDIO LABS. Actually left if off the front,
have nothing more than logo. Discovered another issue, the power on switch is
too close to the power cord inlet, such that some of those ridiculous oversized
power cord plugs will interfere or block the switch. Moved ac inlet off to
size, used to be in center.
Back to the lab, try out the 124B without dc bias. This time, no fancy
transistor current source or long leads. I just soldered a 2k resistor in
series with the generator (simulate 7788 anode), then 47k on each secondary to
center tap grounded. Shoot, all of those nasties were gone. In fact, this
tranny looks just fine today. Flat down past 20Hz, -3dB at 70kHz. I guess it
is all how you drive it. Distortion was low, but a 2dB peak at 25kHz or so.
Heck, that could even be a good thing. No problem, I'll add a small snubber to
primary side where I can tune that out, once on a board. Loading of 2A3s will
also change the transient response.
Sep 05
------
Ok, gotta make sure I don't go down a rathole here. Can spend way too much
time on the DAC and amp, when I need to get the CASTANET out the door. I guess
now that I have CCS designed, the remote control circuits (HT12D and HT12E from
RGP project), DAC logic, and other stuff not common throughout the line can be
done later. The key is to work out all of the common issues such that the
series TEN is synergistic and cohesive. Make it a family. No suprises later.
Ugh, having said that, I just find out I can't get the dark bronze anodize,
only the medium bronze. Better check that with the wife. Anyway, the next
important steps should not be getting mired in microcontroller details, but to
do a preliminary board layout of both the headphone amp and the power supply
for the phono/line stage. These will be the defining common elements, where I
decide on AC input connector placement, and generic positioning of controls and
LEDs. The solutions must work across the entire line. With that done, I can
focus solely on CASTANET board and schematic. Should be able to have a working
prototype by the end of the month. Hey, I can bring it to RMAF with me. That
puts me on schedule to ship half-kits for the holiday season. Then I start on
the phono/line machine and work in a serial fashion.
Ya know, for the power amp, I think I can just use the LL1660S as interstage
tranny. Then the LL1681 for MC input. Yeah, that gives me maximal flexibility
for phono inputs.
Boy, I just can't leave it alone. Had a brain fart, so again looked into this
harmonic balancer thing that Lynn keeps talking about. I use the same balanced
current sinks such that matching of tubes is not important. The cathode caps
are split, with the common mode ac signal fed back into the common mode grid
signal. Not sure exactly what this does yet, but it is in the WE 43A and 93A
schematics. Now, add the third cap, from B+ to cathodes! This adds a SE mode
to operation. That is, you can now remove one of the output tubes and it
continues to work. Added a series R, not sure what value it should be. Maybe
about 100 ohms. This then mimics the same impedance seen looking into the
other cathode? Or maybe 1/2? So now tubes run in both series and parallel.
The idea is to balance this such they both even and odd harmonics cancel. I
think. No output currents through B+ or ground (except via 50k bias).
Hagerman self-balancing output stage with distortion cancellation?
Sep 04
------
Painted the wall, got TV mounted. Now she doesn't like the color. Ok, I say.
It's just primer.
And so I have some misc schematic items to work out, current sources, remote
control, RS232 interface, relays, +/-2.5V regulators, PRBS generator. On the
CORNET type stages I used the 6.3Vdc heater supply as a reference. It worked
ok if you didn't need precision. Added an RC to remove 120Hz ripple and it
fed an emitter follower. Very simple, clean, and no feedback. This time, I
want to get away from the not-so-good heater supply as a reference. Besides,
the power and headphone amps use ac heaters. So looked at zeners. 12V is nice
and works at low current. 6V is temperature stable, but varies a lot with
current. No good choices. Plus they are all wideband noise generators. Ok
with RC filtering. What about the LM385 I use in HAGCLOCK? Yeah, not bad.
Still noisy. Think. Aha, LED as a reference. Duh, a lot of people use them,
so they can't be so bad. And since they are forward biased, they won't have
the noise of an avalanche type. Also, no feedback. That's important to me, I
don't want any feedback in the audio circuitry, not even in their supplies. It
all has to be passive. Meets all my requirements (current sinks for both high
and low voltages). Use two of them in series for cascoding the output NPN.
I'm sure you've seen this all over the DIY boards. Cool think is that they
also act as indicator lamps. A twofer. And if I pull a little trick, when the
output voltage compliance is violated (say a dead tube), the upper LED goes
off. I may not do it that way. But looks like two series LEDs will reference
both channels with cascode current sinks. It'll be driven by B+, which makes
for a relatively constant current operation for the LED (large resistor). And
it's the bleeder for power down. Not a perfect current sink by any means, at
least in terms of measurements or numbers, but sonically it will be hard to
beat, thanks to the simple passive design.
Hmmm, I wonder if I should revisit putting LEDs in the cathodes of the 6072
phonostage. Nah.
Looking more at what it takes to interface I2S to the 18-bit inputs of the
AD1865 or similar. Must undo the ping-pong LRLRLRLR data stream into two
simultaneous L & R streams. Hmmmm. The PCM2706/7 spits out 32 clocks per
L and R (BCK is 64Fs). With some dividers and logic you can mask off bits
and then latch everything at the right time into the registers. None of it
looks very pretty, especially when I try to figure out where to insert the
reclocking. Kinda make you wanna just use the TDA1543. Everything done for
you, bam! On the other hand, what is so bad about non-cophased outputs? It's
like having one speaker slightly behind the other. Given the speed of sound
and the delay, it's equivalent to 0.15". Yeah, less than a quarter inch of
speaker placement. And since it is fixed, all it should do it shift the
soundstage slightly to one side. By maybe half an inch. I have to think
about this some more.
Hooked up the 124B interstage tranny to see what it could do. Ok, after a
false start and some debugging, it drops off at 45Hz with a 15mA bias and 1k
ohm drive. With no bias it is flat down past 20Hz. Then, there is a slight
peak at 20k, a notch at 38k, a huge peak at 65k, and a small peak at 130k.
Wow. Too much snubber tuning to tame this. The 65k can be taken care of,
but you still have the bass rolloff. Nope, this tranny ain't gonna work. I
need to find something else for the power amp. Or I can always go back to
SET.
Sep 01
------
Long weeked, gives me a chance to paint. The house, that is. Going to mount
the plasma TV to the wall.
Meanwhile, redrew all of the series TEN schematics, looking for holes, pieces
I've missed. Described the guts of the DA-10 on the 30th. Here's the rest.
LF-10: Ac line filter into four 182J117 hammond trannies. Primaries can be
switched for either 234Vac or 117Vac. Outputs are all 117Vac. Each of the 8
outlets are driven by their own secondary. Nice clean isolation and filtering,
plus a common power switch on front (turn your whole system on at once).
HA-10: 261C6 power tranny into diodes, two 156G 9H chokes for B+. 6H30 tube
parafeed with 157G 30H plate load, 1.5uF coupling cap into 119DA output tranny,
50k volume control. Heaters ac from same tranny.
PA-10: 22772 power tranny into 5AR4 and two 157J chokes for B+. 7788 input/
driver tube into 124B interstage tranny driving push pull parallel 2A3 into
1615 output. Ac heaters, 2A3 heated by a pair of 166M2. Output tubes run at
230V, 50mA, -40V bias. Monoblock.
PL-10: Two boxes. Power supply is 22772 tranny with 5AR4 or 6X4 into LCLC B+
filter. 166N12 or similar filament 12.6Vct tranny into 4 schottky, dual 6mH
chokes into 10,000uF pairs for +/-5V supplies. Digital supplies tap off of
this for +/-2.5V logic. Heaters get another RC for +/-3.15Vdc. Phono uses
JT-44 step-up into hermetically sealed telecom relays (input select), VACTROL-
based resistive loading (infinitely variable under CPU control), 6072A, 6072A,
and 6FQ7 gain, eq, and follower stages (like a CORNET). Current sink of 6FQ7
biased with 6.2V zener. With different RC values I can use 12AX7 and 12AU7
tubes (maybe I make this an option?). Linestage uses relays for input select,
the VACTROL-based volume/balance control (shunt attenuator) into differential
5687 pair with current sink on tail. VACTROL on outputs implement a soft
phase select, then VACTROL after coupling cap does soft mute. Control is done
with PIC16F687 with flash program memory (update via email?). The PIC18 series
allows programming in C, but at this level of complexity I actually think it
will be easier to do in assembly. Remote control via HT12, I2C for serial DAC
and LED control ports. Maybe do a PRBS for simulated FRYK signal. Remote
control all custom.
Aug 31
------
And so I'm thinking what to call this new line of products. After a while, the
musical names start to get confusing. CORNET, TRUMPET, BUGLE. Ok, but let's
not go overboard. All of a sudden there is a website full of nomenclature that
is confusing and has no meaning. A new visitor has no idea what a CLARINET
might be, for example. Nope, I need to take a lesson from the marketing
experts. Screw the names. Stick with something like KSA-100. I like the
Levinson style of "No. 39" or whatever. Different. So single or double
letter? Would the headphone amp be H1 or HA1? Or H-100, HA-100? Do I include
the extra zeros and dash? Three letters? Lower case? Right now I'm leaning
to PL-10, HA-10, PA-10, DA-10, and LF-10. Or maybe 1.0 instead of 10? The 10
defines the line. In a few years maybe I add the 20 line. Oh, PL means "phono
& line". I can have PS and LS if I want to separate them. LF is line filter.
It is simple and not confusing. Expandable. The uninitiated will not have
difficulty with it. That's good marketing.
Checking out the new stereophile (September, I get mine weeks after you). The
Pro-Ject phono box sold more than 100,000 copies before 2002? Wow. I've sold
a little over 500 BUGLEs. On the other hand, I bet more people on Asylum talk
about the CORNET than they do the phono box. He he he. Then I see Fremer
giving a huge thumbs up for the EXP. I'm proud to announce you can get a lot
more for your money with a PICCOLO.
Looking over my old PROJECT X folder for the RGP design stuff I did, see if it
has some good ideas for the TEN series. Had notes for the ADuM140x series of
isolator chips. Maybe I can use these instead of the DSL transformers for
coupling of I2S between the USB chip and the rest of the DAC. Then again,
these could add a lot of jitter. For resistors I was looking at the Vishay
Z-Foil precision bulk metal types. Don't need that sort of precision, but I
like the other electrical characteristics.
Ok, so what about this new 5th order DAC filter? Well, the converters I am
considering (AD1865, PCM56) have 1mA output current. Make the resistive load
50 ohms, just like the HAGDAC, and you get 50mV output signal. This is high
enough to maintain SNR (ten times better than phonostage). It also presents a
reasonably low compliance at output of converter. Works great with the
PCM1704. Ok, so here is the new filter I came up with. I started with a
butterworth type and tweaked coefficients to improve transient response. It is
a compromise between step response and anti-aliasing attenuation. I made it
symmetrical such that the inductors are wired up in humbucking arrangement, so
they will cancel any influence of external fields. Also went with nearest
standard component values. Looks simple, eh?
DAC filter #2
I get -1dB at 20kHz and -52dB at 44.1k. The -3dB point sits at about 23kHz.
Not too shabby. Was not able to put in a peak for sinc compensation. Oh well.
DAC filter #2 frequency responseDAC filter #2 time response
Searched for good boxes to put a remote control into. I like this one from
Polycase. Comes in a variety of colors and the outer edge is rubber, for a
very nice tactile grip. Comfortable.
Polycase remote
The other choice from last year was from Teko. I like it because the top
recess will fit a anodized panel to match the front plate of the PL-10.
Teko remote
Which do you prefer?
Aug 30
------
Backing off on this wierd common grid output load for the DAC. Something about
it just not right. So back to the same approach I used in the HAGDAC. I know
it works. And if I change the HAGERWORTH from a 7 pole to a 5 pole, then I
have a pair of coils in the middle, balanced at LF, and so I wire them up in a
humbucking arrangement. Duh. That would help to cancel out any stray magnetic
fields impinging on their territory. Still use the 7788 or 6C45 as normal
output stage.
Yet another issue is the logic interface between the PCM2707 and the DAC. One
spits out I2S and most of the others read in B2C or whatever. The PCM56 would
require some extra glue logic. The TDA1543 is a perfect fit, which might be
why so many people use it. I want to do better. After some more research, I'm
led to the TDA1541 and AD1865. I sort of prefer the latter. No digital filter
chip. Must be able to actually buy some of these things on the surplus market.
Looks like the AD1865 can still be had, although I'll probably have to buy 100
at a time. Ok, so the DAC is now looking like a PCM2707 -> DSL transformers ->
PLD or other glue logic -> VCXO PLL reclocker -> AD1865 -> Hagerworth passive
filter -> 7788 output stage.
I need to create some new artwork for the world tube directory advertisement.
It will be the usual 1/6th page B&W I always get. What should it be? Do I use
the classic VACUTRACE? Promote kits? Any ideas for what I should put in the
ad?
Mackris called the other day, pretty much convinced me to show up at RMAF, even
without a room. I guess this would be a better event for me than VSAC.
Besides, I'm in the market for a new pair of speakers, this would be a great
opportunity to hear a bunch. Curious about the Zu Druid Mk4. It's kinda my
style. I need something to go with the upcoming 2A3 PPP amp. Highly efficient
full-range driver or horn setup. But it HAS to have bass. Anyway, I think I
will go to RMAF, press the flesh, make some more contacts. Work the crowd for
HAGLABS. I'll probably bring a PICCOLO with me. Maybe I can pass out
brochures to those that ask. Timing is good, as I should have most of the line
complete for RMAF08. Even the DAC. That could be used for my big "launch".
Way cheaper than CES.
Aug 29
------
Thinking about the new DAC again. If I do put everything in one box, there
will be a lot of magnetic spray from the chokes pretty darned close to the tube
amplification. That's ok, the problem is if I use inductors in the filters.
The type used on the HAGDAC are shielded, and might be ok, unless signal levels
are really low. Then you'd get 120Hz hum induction. So it might not work to
use the same topology, current output from DAC (like a TDA1543) into a passive
HAGERWORTH filter, then into a tube gain stage. Hey, you know a 7788 used as
triode would work great here too. Just a simple common cathode stage with no
cathode follower buffer. Or perhaps as DS suggested, skip the 7788 and use a
6C45. I kinda like that too. Hey, maybe as a plate load, use the hammond 124B
transformer? Cool, constant current operation and isolation. Hmmm, I have to
look into this tranny as a line out for the linestage maybe. Nah, no way can
that thing have low enough bandwidth. Ok for the power amp, though.
I sketched out some other possibilities. How about a tube version of the
common base stage? Hmmm. Let's say a 7788 common grid biased with a CCS.
Use a slow opamp stage to create proper gate dc bias to put cathode right at
0V. This gives a low impedance load to the current output of something like a
PCM56. The plate resistor has to be low, though. At 1mA output, we use a 2k
plate resistor. This should result in 1.4Vrms full scale. The reflected
cathode impedance is then maybe 50 to 60 ohms (if the data I found on net to be
accurate). That's only a 50mV compliance swing at the output of the DAC.
Probably ok. This is a very nice topology, except that it doesn't allow much
for a filter. Best I think I can do is to add an LC on the output. Also
requires the noise and ripple on B+ to be extremely low. Hmmm, an LC filter
can be peaked slightly at maybe 18kHz, thereby compensating for the sinc
rolloff (without digital reconstruction filter), and then give steep rolloff
after that. Simple. Not exactly brick wall. But shoot, so many people are
finding the nonos to be so musical. I need to somehow capture that magic, yet
still improve on it technically.
In aXp I noticed a good letter that suggested using an LED as a low leakage
clamp diode, instead of something like a 1N4148. Wow, the differences are
huge! So how about using a red LED as a clamp diode to ground at output of
DAC. That keeps the current sink from yanking on the DAC too hard until the
tube can warm up. And here's a cool idea. Instead of painting the LED dark
(to prevent photocurrents), use a VACTROL. And then tie the resistor part of
the VACTROL as the output resistor that biases the coupling cap to 0V. During
turn on, the LED lights up making the resistance very low. The theory is that
this will reduce turn-on thumps.
Ok, so I did some sims on this DAC filter. It's only a 2-pole rolloff, so you
can't expect much. Still, it's better than no filter at all? I hate sending
RF garbage down the pipe only to expect the next piece of equipment to deal
with it. This should smooth out much of the edges, cut down a little on
aliasing. Interestingly, I discover it presents a notch in the impedance seen
by the DAC. Hmmm. This occurs near the -0dB crossing at the output. And
there is a 1dB peak at a lower frequency, the intention was to make this
compensate a little for the sinc function of sampling. If I put the notch at
22.05kHz, then at that frequency the impedance seen by the DAC drops from 100
ohms down to 50 ohms or less. Is that good? I dunno. Then there is no
rolloff in the passband, only a smooth attenuation in the image band.
DAC filter #1 frequency response
The step response is a simple slightly undamped 2nd order function. Zeta = 0.7
or so. But since all recordings have anti-aliasing filters, well then you'll
never see this on playback.
DAC filter #1 time response
Of course, I can place the notch or peak anywhere I want. It just seemed
natural to notch it at 22.05k.
Aug 28
------
Phew! Finally caught up on orders. That is, from the vacation backlog. All
of those delayed HAGUSBs are in transit. Back to our regularly scheduled
programs.
Aug 27
------
Just spent a few hours cutting up HAGUSB chassis. Pain in the butt. It helps
to do it in batches. Discovering the XLR version is a lot of work, way more
than the extra $10 I charge. Oh well. I found a way to make them look even
nicer.
Meanwhile, did I mention I ws changing to a 6FQ7 for the phono output? I think
it will be better than the 12AU7.
Also, the 22772 power transformer came in. Wow, looks pretty nice, the
construction. Well built. Big. I measured it, damn, if it ain't a perfect
fit into my chassis. Not a quarter inch to spare. Takes up a bit of board
space, though. Still, I think it's the ticket. The Hammond 124B also is
fairly hefty. Quite substantial for an interstage.
Aug 26
------
So I asked Lynn Olsen (who knows a lot of stuff) about that self-balancing
output stage topology. He was immediately able to point out the drawbacks,
mainly that it clips, and clips hard. I forgot about this, as Allen Wright's
PP amp has the same issue. Also, the harmonics are not good as even orders get
cancelled. I now realize the beauty of the karna amp and early western
electric designs. They are not differential, merely push/pull parallel. This
is significant. Done right, you end up with basically two SETs operating in
parallel without all the iron headaches. Doh. Now I am trying to figure out
the best decoupling, minimizing output current loop size and capacitor issues.
Maybe I need to put the amplifier project on the back burner. I just find it
so damned exciting, though. After a lot of searching, I'm now looking at the
7788 in triode mode for the driver. Lot's of potential, that tube. I've heard
folks say it makes a great phono or mic input tube. Well, I think it might
also do great as a driver.
Allen Wright PP output stage
As for the DAC, no way to fit it into the preamp. It has to be a separate box.
Which is good, because I can in sure a valid +/-5V supply. Gives me more
leeway for a converter chip. So maybe the PCM56. The PCM63 looks to be really
hard to get nowadays.
Aug 24
------
Now using the code name PROJECT Y for the new HAGLABS series. This replaces
the previous PROJECT X and ONE programs. Spent the morning working out
mechanical fit details, arranging connector placement, controls, etc. I ended
up removing the mono switch and having only 3 line level inputs. The concept
has to work for each machine, so they look like a perfect fit (that way you'll
buy more than one). Extremely tight fit, but I think I got it. Now I can
focus on putting the schematics into CAD. The plan is to have everything up
and running my Christmas, except the DAC. The lineup is:
HEADPHONE AMP
POWERLINE FILTER (8 outlets)
USB DAC
POWER AMP (6-10 watts?)
CONTROL PREAMP (phono + line, 2 boxes)
Everything is single-ended RCA jack. Pricing will be less than competitors,
yet with more features , and way more innovation (and probably better sonics).
The headphone amp will be also sold as a half-kit under the HAGTECH brand. I
think I might do the same with the power amp. Wow, all this because someone
posted on the forum they wanted a CASTANET half-kit two months ago.
Riding my bike, clears the head. And so I think for a minute about the DAC.
If I want to do something like a CHIME, then I'll need a power supply quite
similar to the CONTROL PREAMP. Will it fit? What if it ends up being another
two box unit? That's not worth it. I have to look at fit. Or, why not do
something the RGP did, and include a DAC in the PREAMP? I already have +/-5V
taps from the heater circuit, which I'll regulate down to +/-2.5V for the CPU
and digital logic stuff. Thinking I am ready to pull a new trick I've been
saving. Interface a PCM2707 I2S output via 3 DSL transformers. I can make
these run fast enough, the benefit is that they provide the necessary audio
ground isolation. Then a reclocker VCXO borrowed from HAGDAC, and a JIMDAC
type converter. So, I need to figure out if there is room to jam in a DAC
daughter card into the PREAMP box. Tight. The other question is if I can
get full +/-5V supplies. Worried about low-line ac conditions. Might just
fall out of regulation. That could limit me to 5V converters like the
TDA1543 or the AD1955. No hope using a PCM56 or PCM63 (which is sort of the
one I wanted).
And then I thought about the line filter. Why not do something more than
just your average filter? Here's the brain fart. Use 1:1:1:1 isolation
transformers to spit out balanced lines. A tranny will filter out noise and
make a cleaner ac line, guaranteed with no dc. I find the Hammond 182J117 is
the right size. I can fit 4 of them into one box. The primaries can be wired
for either 117/234, the outputs not paralleled, but each run into their own
outlet. That gives me 8 completely separated outlets! Each one has their own
balanced ac drive. All are somewhat isolated and filtered from each other.
Limitation is 50W per plug, though. Perfect for my 2A3 PP amp. This
eliminates the 120Vac only problem. Machines can now work in EU if a line
filtered is purchased. Plus, you get excellent line filtering. I can make
this box a real gem.
Aug 23
------
So I ask my wife, who has much more fashion sense than I, to pick out a color
scheme for the new chassis. Limiting my choices to the few available from that
frontpanelexpress place, she chose dark bronze with yellow text.
Panel coloring
What? Ok, so what LED color? Red! Hey, that makes things cheaper. I would
have never come up with this combination, but there is no doubt in my mind it
will look nice. Who else uses red LEDs these days? Clever, actually. The
off-gray paint for the top and bottom of chassis seems to be the only choice.
And so I asked about panel size. Fit inside neatly or oversize it (the classic
trick everyone else uses). She said the small, neat, and compact look was
nicer. Then I mentioned there would be vacuum tubes sticking out the top. Oh,
well in that case, go with the bigger one. Ok, so there it is. Understated,
yet classy. Now I have to ask what is the best knob size.
Ok, go back to the RGP schematics, see if there is something I forgot. Aha, I
had re-done the output stage to not use transformers. A simple differential
5687 stage. Well shucks, that will fit here nicely. And I can get rid of a
tube. EVen better, as it is not a cathode follower output, but a low impedance
plate drive of about 2k ohms. That's better than the CLARINET, which has
proven itself perfectly capable. A very ballsy tube. Should have the dunamics
and slam I crave. And boatloads of headroom. My old volume control (vactrol)
should work fine. Just need to make a new schematic of the CPU, DAC, LED
control, and remote. Only issue is that there is hundred of variations of the
PIC processor. Which to choose that will not go obsolete? The other question
is how to implement the FRYKLEANER circuit. Can I make one digitally? Or do
I insert a FRYBABY? I think maybe I can make a PRBS generator out of one of
the internal counters, then use a DAC output to control gain. That would make
essentially the equivalent, but with more control, needed for a long fade to
degauss.
Looking at switching arrangements. Lots of relays. To be truly a high-end
machine, it needs plenty of inputs. Two phono plus four line. For phono, I
have an MC input with either 20dB or 26dB gain, and one MM jack. Maybe I can
add a monitor output jack (for taping), along with the listen output jack.
That gives me nice symmetry across the back. I really like the vampire pcb
mount jacks, like in the TRUMPET. They have a stereo right angle pair, which
should be perfect. Hmmm, could also put in a PICCOLO headamp to make the MM
input cover both gain ranges. That plus step-ups for the MC input.
Ok, so here's what I'm looking at. This drawing shows the basic layout for the
new series (needs a name!). Top is the phono/line, middle is the power supply
for it (power amp looks the same), and bottom is the headphone amp (CASTANET).
Front plate is removable. Hole at upper left is a fresnel lens window for the
IR remote. Total size, or volume of the two chassis unit is about 1/2 that of
the janus, or any other competitor. Smaller than a steelhead, way more
features.
HAGLABS new chassis look
Aug 22
------
Did a quickbooks summary of sales over the past 7 years. I just past a
milestone last month and didn't even know it. HAGTECH has now sold over 1000
phonostages in total! The printout also indicates which products have been
successful. That comes in two categories, those that sell a lot in numbers,
and those that sell a lot in dollars. Here's the listing, where I give + and -
for their relative ROI (on a percentage basis), and $ for their absolute value.
BUGLE +++ $$
BUGPRO + $
CHIME o $$
CORNET ++ $$
CYMBAL -
FRYKLEANER ++ $$
FRYBABY + $$
HAGUSB +++ $$
HAGCLOCK o
IRIAA +++ $$
OBOE --
RIPPER o $
SUPPLY +++ $
TRUMPET + $$$
UFO -
VACUTRACE + $$$
I left out the PICCOLO and FRYGOLD as there is not enough data to make a
determination. Maybe this is hard to interpret. The CHIME makes good money,
but development was so costly that it barely broke even in terms of ROI. The
OBOE was a flop. The UFO and CYMBAL projects lost money too. The TRUMPET and
VACUTRACE brought in a lot of revenue, but have only moderate ROI, as they too
had very long and expensive development cycles. Oddly, the IRIAA scores very
well. That simple little circuit has brought in more cash than you could
imagine. Half-kits of BUGLE, CORNET, and SUPPLY have been very successful, but
still don't come close to the revenue generated by the TRUMPET or VACUTRACE.
The RIPPER and HAGCLOCK are pretty much break-even. Good products that didn't
take off (I still use mine).
Ok, enough of that. We know where we have to go. HAGLABs line of machines
sold via dealer network, and more HAGTECH half-kits of the type actually
requested by people (such as a PICCOLO and CASTANET). I have to be careful not
to waste time on any more OBOE type projects.
Meanwhile, I apologize for all of the delays getting orders filled since I got
back from vacation. Still a pile to go. Was still short on parts, no USB
cables! Doh. The XLR HAGUSBs will go out Saturday. Did a round of part
re-stocking yesterday from digikey, mouser, aes, mcmaster, and jameco.
Have parts to build the Hagerman Self-Balancing Output Stage on order. Will do
another breadboard like I did for the CASTANET.
Ok, so I just did the schematic design for the phono and linestage sections. I
stayed with my desire to use the 12AY7 tube, which should give more punch and
lower noise. Came up with resistor & cap values, biasing, etc. Only question
is if I stay with 68k plate loads or go with 2mA CCS. The latter will eek out
a little more gain, but make the EQ even more dependent on tube parameters.
Right now, I think the CORNET2 design is about right. The CCS might make this
positive attribute go way too far. Anyway, with resistors, phono gain should
be 38dB. In front of that is a 20dB or 26dB step-up tranny ratio.
Figured out how I can put some of the RGP features back into this machine. The
one killer feature would be switchable polarity, something the single-ended
stages make impossible. Ok, so add one tube, make the linestage differential.
I got it. Also re-worked the MC inputs so that I can add a built-in degaussing
mode. I like the aesthetix janus, for $6.5k. That's pretty much my
competition for this. So I'll match them for features, and then add. Since I
have the degauss, the self-frykleaning capability is a slam dunk. Even cooler
is that by default the machine will clean (burn-in) any cable connected to it.
So here is my present list of modes:
INPUT (select)
LOADING
BALANCE
VOLUME
POLARITY
MONO
BYPASS
DEGAUSS
CLEAN
I leave out MUTE because the volume control works so fast. Also left out is a
standby mode or remote controlled power-down. To do so would require more
power supply sections. Nope, I want to keep with the clean choked inputs.
Circuits looking very good. Should be able to get really close to the RGP /
TRUMPET sound, but with 1/2 the tubes. Simpler is better? Wow, this is a lot
of stuff for two small boxes. And it will fit. I guess my dream is not so far
away after all.
Aug 21
------
Didn't sleep well last night. Been thinking, if I sell this new series under
the HAGLABS banner, then are they going to look good enough? The circuits are
beautiful, and I'm happy with the progress with electronics and sonics, but my
achilles heel has been traditionally the mechanical appearance or industrial
design. Ok, the TRUMPET was cool. But this is a plain off-white box. Even
fancy panels won't dress it up that much. It is very staid. Nothing
remarkable. Look at it this way. The preamp (phono/line/remote) will probaly
retail for $4k or $5k. It's a bargain from a features and sonic perspective,
the problem is that it won't look like four grand. Most of the new stuff you
see in stereophile et. al. focuses on appearance. Wierd sculptures, alien
craft.
Then, at 4am I realized that the front plate could be oversized. The side
extrusions on this chassis allow you to position them fore/aft almost at
random, relative to top cover. At first I thought it was a flaw in the design,
however I now realize I can exploit this to my advantage. Seems to me a big
thick (1/4" or 3/8") front panel with a fine brush or sand finish puts it into
the big leagues. It takes the emphasis off the top cover visually. Like my
friend AH said, "If I'm gonna pay ten grand, it damn better well look the
part." And he's right. Sonics is not enough to sell. A product needs to
look effing great too. Just like a car.
Why do I agonize over this? You'd think I'd just design a custom chassis to
beat all. Well, it's all about time and money. My design team is small, my
budget is tiny. Even after ten years in the business, I'm still in the mode of
having to bootstrap myself. That is, I don't have a fortune to invest in new
products. I'm still whipping them out on a shoestring.
Here's one scenario I am contemplating. The new HAGLABS will start with the
CASTANET style line of machines, rather than the ultimate megabuck RGP I was
considering. It's a matter of practicality. Initial line would be the
headphone amp (aka HAGTECH half-kit CASTANET), the power amplifier, and the
phono/line stage with remote. I can then add a DAC later. Maybe a line filter
too. A line of products in matching chassis. Of course, the centerpiece will
be the phono/line stage, which is what most folks would buy. The power amp
with the novel Hagerman Self-Balancing Output Stage is way cool, but not likely
to sell much. Anyway, the idea here is to build prototypes or pre-production
units and show them at VSAC08 next May. Actually, I'll have them up and
running by Christmas. I can team up with Mackris or similar for the show. The
CASTANET will be sold as half-kit in November, just in time for the peak
holiday season. I may also end up selling the power amp as a half-kit, not
sure. I have to be careful, though, as doing so may kill sales of assembled
units. Anyway, if I get a lot of interest at VSAC, then I go for dealer sales,
maybe starting with MD and AA. Might have to do CES09.
Hey, maybe then I can do a remote control half-kit for volume and select?
Something that could be back-fit into other projects. That would sell big.
Oh, by the way, that solution I came up with for a 2A3 or 300B parafeed using
the 119DA output tranny, wire it up like this. Should work pretty good.
2A3 parafeed into dual 119DA output trannys
Aug 20
------
Well, that vacation seemed to have done me some good. The time off has cleaned
out some cobwebs, I can think a little more clearly now. After working out a
solution for the CASTANET, I've gone back to the phono and power amp circuits.
I was stuck on power supplies. Well, it looks like that Fender replacement
tranny 22772 from AES will do the trick. I'll have to order one and see if it
fits. Then I can stick with this Mouser chassis. And so I worked out a
schematic for a 2A3 push-pull power amp of about 6 to 8 watts. Uses same
output tranny as the CYMBAL, but implements the new topology I invented the
other day (or perhaps re-invented something from 60 years ago). Seems to me I
just have to use it. Call it serendipity. Anyway, the 2272 tranny fits
perfectly with a 157J 10H choke. I can fit everything into that small box for
a powerful yet compact monoblock. There is no reason it can't sound fantastic.
The problem is the phonostage. No point just doing another CORNET, better to
take it a notch up and use a choke power supply. And while I'm at it, go for
current source plate loads on 12AY7s. The hard part is choke filtered heaters.
I have a good solution, but it requires a separate 12.6Vac ct tranny and two
6mH chokes. A twist on what I did in the TRUMPET. The answer is to use two
chassis! One for supply, the other for tubes. That solves also the hum issues
with MC step-ups. Costly. But hey, not if I add a linestage to it! What if I
make the combo phono/line preamp as proposed for HAGLABS, but in single-ended
configuration? The cost of adding the linestage parts is almost nil. All of
the cost is in the supply and chassis'. With the combo, I have 5 tubes in the
amplifier box. To make this killer, I skip the traditional knobs and go
straight for a remote control. Why not do the CPU circuit from the RGP? This
solution is sort of a middle ground between the CORNET2 and the RGP. It might
actually be small enough for me to chew. At the moment, the RGP is out of
reach, financially (without external investment). Hmmm. It could even have a
DAC option? Two phono inputs? This could get me there, I can finally have the
opportunity to introduce my way cool remote control.
Aug 19
------
Burned the CASTANET in for a few hours, as it always takes the edge off
capacitors, makes test listening easier. Then I realized I forgot to put the
common mode reference on the 6.3Vac heater. It's just floating, picking up all
sorts of coupled noise from the tranny. Added a 200 ohm to ground in each leg.
Bingo! Almost all of the noise was gone. No more buzz, hum is way down.
Ok, so it's time to run somebode plots. Holy moly, it's all messed up. Looks
like crap. The spectrum has a wierd tilt to it, which makes no sense to me.
It's not what I hear. What I hear is a lack of dynamics and softness, and not
enough bass.
CASTANET frequency response?
There is also a big 6dB drop in level between 33 ohm loading and no load. Wow,
that translates into a 5k ohm plate impedance! I calculated about 1/5th of
that. Aha, another error. I forgot to put in the cathode bypass cap. Jeez.
I think a value of 100uF should do the trick. That should bring the rp of the
6H30 way down to where it should be. But that frequency response? I had been
using a 10x probe into my HP 333A ac voltmeter. Hmmm, usually I go direct.
Voila! Connect with a 1x probe and the frequency response problems all go
away. Doh. I need to be more careful. Ok, now with the bypass caps and
proper measurement technique, the CASTANET prototo has wonderful bandwidth with
superb 10kHz square waves (into 33 ohms). A little shy in the bass, as the
-3dB point is just above 20Hz, but that's about what I expected. Output
impedance now measures 9 ohms, for a damping factor of 4. Not bad for zero
feedback.
CASTANET frequency response (actual)
Unloaded (or what a Sennheiser would do), there is an odd 2.6dB peak in the
bass. I can't figure out what causes it. Will have to ponder. What I added a
100 ohm load to the 8 ohm tap this came down to a well-controlled 0.5dB peak at
50Hz. This would tend to lower output impedance even more, which might be a
good thing.
Whatever, I couldn't wait to get the phones plugged back in. Yeah baby, yeah!
That's more like it. Waaay better sound. This version has all the punch and
clarity of the OBOE, but with that magical musicality and lack of staleness
you get from tubes. Finally. I thought I was going nuts. Of course, the
120Hz hum is still there. Was hoping the 30H choke would bring it down enough,
but no. It measures about 1.8mVrms at 4 ohm tap unloaded. That needs to be
20dB or more better. Fortunately, the tranny spits out high when not at full
load, so I have an extra 10V or so on the B+. I can fit another 9H choke and
200uF filter in the supply. More bucks, but it will make for super low noise
performance.
I just couldn't get enough of tracks 3 and 4 on stereophile's Test CD2. The
drum and guitar picking transients were absolutely overwhelming. Fast and
clean, hitting you like a sledgehammer. Bass was solid and articulate. The
25Hz or so rolloff wasn't apparent at all with music. The sound was huge and
clean. No problems cranking it way up (plenty of gain in the amp), the
headroom just kept going. It never ran out of steam (cannot get anywhere near
clipping). On track 7 I finally heard the violinist breathing. Never noticed
it before. So, all is well. The design has validity. I just need to figure
out packaging.
Aug 18
------
So I stayed up last night drilling away, making a breadboard for the CASTANET.
Mounted all of the iron and added a VACUTRACE board for the tube socket. It
makes things easy to wire up. Wired it up this morning. Turned it on, no
smoke, all voltages doing exactly what they were supposed to do. I love when
that happens. Ran some test signals, all looked pretty good. The low
frequency response was shy. With no load I measured -3dB at 80Hz. What? Oh
yeah, I forgot it needed to be loaded. Added a 33 ohm dummy load to the 4 ohm
tap and then response was flat down to 20Hz. That's what I had calculated.
Dang, I forgot the 600 ohm headphone on 8 ohm tap would not load the circuit
properly. The problem is clearly the 30H being too low. I need more choke.
Top end was good, nice fast square waves. Clean edges. Tubes biased up just
right. So lets take a listen. I should have used the CD player, but instead
hooked up a RIPPER to the TT. Not enough gain, but gives me a quick comparison
between two headphone amps. The CASTANET had just about the right gain. Sound
was fine, but a little bass shy. It was there, but not perfect. That can only
mean the impedance of the Grados is not constant. Either it drops in the bass
region or goes high, both will lead to loss of bass (due to pad, or 30H choke).
I'll have to measure them. There was also a lot of 120Hz hum and buzz. I did
not expect the buzz (could just be wiring), but at 30H there is not enough
impedance to perform PSRR. Clearly, this topology requires a second choke
filter in the power supply.
CASTANET prototype
This is a good start. It means I'm going down the wrong path. Many things are
right, but the 30H choke is not the answer. I either find a bigger choke or
switch to CCS and a higher voltage supply. Methinks the latter is a better
answer, as tube linearity improves. I do worry about the loading, though.
Without feedback I still have to get the output impedance low, or the Grados
won't have that bottom bass. This also means I have to find a higher voltage
power transformer. One solution I had was to use two of the same, tie
primaries in parallel and secondaries in series. Unfortunately, that causes
a 60Hz unbalance unless I also create a B-, like in the TRUMPET.
Sigh, the domino effect. New power tranny might lead to different chassis.
And so on.
Aug 17
------
Ok, posted the top ten photos from vacation. At least ten time zones away.
Top 10 UK photos
Back to work on CASTANET series. Still looking at power tranny alternatives.
I'll buy some more samples to see if they will fit into the chassis. So many
paramters to meld. Anyway, the cool thing is I had another brain fart.
Sketching up some 2A3 output stage stuff I came up with a new topology. It's
push-pull 2A3 in a wierd configuration. I don't want to give it away yet.
Not normal. Balanced with only one cap. Great PSRR? Minimal output ac
current loop that doesn't even touch ground. Closest thing I've seen yet is
the Karna amp from Lynn Olsen. But even that is way different. Holds a bit
of promise, I'll have to look into it. Not where I was originally headed,
though. One clue, it does not work with the 119DA output tranny.
Ok, what the heck. Here it is. Schematic shows the basic concept. The
output stage is ac differential, but not dc. Each cathode gets a current
sink, which force an almost perfect dc balance on the output tranny primaries,
with no adjustments necessary, even if tubes are not matched. Now look at the
ac signal current loop. It's small and controlled. Only outside connection
is the B+ center tap. If tubes are not matched gain, then I'm thinking the
cap will force a balance by driving the cathode voltages appropriately. In
theory, with mismatched tubes, you still get a perfect ac and dc signal balance
in the output. The driver stage helps to make this work. The balanced inter-
stage tranny give matched ac to both sides, plus a very low dc resistance to
ground (reference), which means we don't worry about grid current modulation.
If this doesn't work, then the output cap can be split, one cap each from
cathode to ground. You lose ac balance, but I think that's ok. Coupling
tranny would be something like a Hammond 124B. Main disadvantage of this
topology is that the cathode cap has to be really big, like 100uF, and it is
right in the signal path, so must be very high quality.
Hagerman Self-Balancing Output Stage?
Aug 16
------
Ok, I'm back! Spent a few days digging out from a pile of emails and orders.
The 6moons review of HAGUSB sent orders for those through the roof, and I
quickly ran out of some parts, so the balance of those orders will ship next
week.
6moons HAGUSB review
Trip was great, lots of time to forget about whatever it was I was doing. The
relevant highlights were the Orkney Wireless Museum, one room stuffed floor to
ceiling with cool radios, and those used LP shops near Notting Hill Gate. I'll
post some pics soon.
Parts came in for CASTANET. I love the chassis, paint job is really nice. The
front and rear panels a bit thin, though, which is ok as I plan to substitute.
Wish chassis came in a larger version. Still need to work out various possible
configurations for amplifiers. This could lead to something good. The 119DA
output trannys look way better than I thought. I expect they will end up
sounding great. A true bargain. Once I catch up on orders, I'll wire up the
prototype CASTANET circuit and have a listen.
Jul 26
------
Ok, that's it for now. I'm off on family vacation for the next few weeks. Be
back 8/14.
Jul 24
------
The 6K3VG from allied looks to be a winner. Almost a perfect replacement to
the 270BX from hammond. And it's only $22! With a 5V rectifier, it'll put
out about 250V B+ at 60mA with a choke. Also has a 6Vct winding. Could be
a great alternate for the CASTANET. But it won't fit inside. Maybe I need to
drop that chassis path, find something else. I'm getting tired of putting the
big bell trannys on top. I think the retro look is out. It worked ok when I
did the CORNET, but now it is passe. Customers looking for something much more
modern and aesthetic. All of those shiny, curvy chinese chassis making an
impact. I really think I have to pull everything except maybe tubes inside.
Jul 23
------
Some things not adding up. At least for the CLARION2. Not enough B+ coming
out of the transformer arrangement for choke input. Need to get 210V to 220V
across the 2A3 to make it worthwhile. So figure 215V at 60mA at -35V. Really
good sweet spot. It would take something like a F22772 fender power tranny to
make this work. Lots of dc losses in chokes and/or set. Using the dual
strapped 119DA is clever for an output, but then you have to buy good chokes
and caps to make it work. In the end it costs more than a UBT3, which turns
out to be a bargain. So maybe an F22772 and UBT3 combo for a 2A3 amp? Not
sure how to physically fit something like this into that tiny 9x9 chassis. I
still like the thought of a parallel 6072 as the driver. Can use CCS for plate
load. Looks like it can be suprisingly good. Sure makes me envious of those
designers who can just specify exactly what they want and them get it cheap.
Also very uncomfortable about putting RCA jacks on front panel. That is just
way too wierd. Electrically better, but I think likely to be completely
rejected by consumers. Is it the uniqueness that sells, or conformity?
Well, parts on order (I wish I had added an F22772). I need to see them in my
hands to better understand how I can best exploit them. Then I'll build up a
headphone amp, see if the chokes work across audio spectrum or not. Listening
and measurements will make the decisions for me.
Jul 22
------
Doh! Again. I solved another problem below without even realizing it. Some
times I completely miss the obvious. Usually I am just too far out there. I
said the balanced heater circuit ended up creating +/-5V, which was a problem
because I was aiming for +/-3.15V. Well shoot, what's the perfect supply for a
DAC? Sheesh. I could use something like an AD1851 connected to a PCM2707 for
a nonos DAC. The supplies are practically free. And they are quiet. Just add
some LDOs and you're good. Then I thought of a way to increase the B+ a
little. I can stack the secondaries. The high voltage winding can be on top
of the heater winding. That would give me an extra 6V that might come in
handy. I dunnno yet. The drawback is that I can't put a relay on the center
tap for B+ delay. However, that would be acceptable for the CLARION monoblock.
Speaking of patents, check out the article from pc magazine 7/17/7 page 68. It
shows a new technique for combining several small projectors into one large
combined image. It uses CCD camera feedback and processing to manipulate the
images for convergence. Similar in ways to my patent #5,793,441.
Oh my god, this is what my competition sells for $1000? I am stunned. This is
$30 in parts.
Expensive phonostage
From May stereophile page 48: "They focused on CD for several reasons, chielf
among them that they felt universal players accumulate solutions of compromise
and cannot therefore excel in any of the three standards." Yes, this is
exactly what I said three years ago when I designed the CHIME. And you know
what? I think I'll stick to it. If I do make a DAC in the CASTANET line,
it'll probably be USB input only, optimized and reclocked for CD music.
Thinking some more. If if use the 6072 on a new phonostage, maybe I can switch
to a 6CG7 for the output, rather than a 8514A. What I really need to work on
is the ability to do my own silk screening in the shop. That would save a ton
of product cost, not having to send out for panels.
Jul 20
------
Not enough time to build up a CASTANET prototype soon. I leave on family
vacation in a week. Will just buy the parts now so they're sitting here when I
get back. Can't wait to wire one of these up.
Spent all day working out various power supply designs. Just in case, I did a
supply for CASTANET if I switch to CCS on output. That makes things easier on
the supply, as the CCS takes care of a lot of ripple rejection. And then I got
to thinking. I really like good power factor. I think it is the number one
reason the TRUMPET sounded so good, not the fact that it was differential. So
imaging a single-ended CORNET style phono with TRUMPET style power supplies.
Good power factor means choke input supplies, no diodes pulse charging caps,
like every other design out there. And I mean all of them. Because I want to
do the choke thing on the heaters too, not just B+. Well, this leads to a lot
of iron, a low of magnetic fields, and more cost. But not that much more.
Pretending I used the same chassis, I came up with all new designs for a phono
and a monoblock. The phono has 6.3Vdc heaters from balanced bipolar choked
rectification. Normally this ends up at +/-5Vdc with a pair of 6.3V windings,
but I made it lossy in an LCRC topology. Result is about 20mV ripple. Then
for B+, using the small power transformers (that fit under hood), I can barely
squeeze out 210Vdc or 220Vdc. That's way lower than what a CORNET requires.
Ok, how about using 12AY7 or 6072 tubes for the gain and EQ stage with CCS?
I think noise will go down, linearity up, dynamics too. Heck, I almost don't
need the CCS, a 50k plate load might do the trick. I like this tube. Borrowed
from the RGP design. Really tight fit inside this compact chassis, yet I still
might be able to fit both Lundahl step-ups and adjustable loading inside. Only
question is if the Lundahls can handle a mere 5" center-to-center spacing with
the chokes. I already know from TRUMPET experience that these things put out a
lot of magnetic spray.
The one drawback is that I have to put input and output connectors on the front
panel. That's a bit odd. Then again, bottlehead has everything on top. I
think perhaps the compromise might be worth the optimization of signal path.
Why screw up the design electrically just to route sensitive signals to the
back? I have to ponder this. Power and ac switch on back, RCAs on front.
Also did a monoblock based on CLARION using a 2A3. And get this, with a 12AY7
strapped in parallel as the input/driver stage. I like things simple. No
extra stages. The one question is how the 2A3 sounds when not driven hard.
Looks like it'll put out only 2W, not the normal 3W or more. Pushed operation
down into a hopefully sweet spot. Oh yeah, uses the same UBT3 from one-
electron. I can make it buildable in mirror layouts. Three trannys and four
chokes on the inside, UBT3 on top middle, with 2A3 in front of it. Binding
posts also on front.
Ok, so there it is. I figured out power supplies and chassis for a new line of
DIY machines. Super compact, choke inputs, CCS loading. I'm thinking maybe a
linestage with remote control would be a good addition. Having a remote
eliminates the problem of having the RCAs on front. Sort of a paradigm shift.
Why hide those expensive cables with the shiny machined connectors? Put them
out front. In a way, it makes perfect electrical sense. Power in back, signal
in front. Do not mix them. I wonder if such a concept is acceptable to the
consumer base. All I need now is a DAC and power line filter. The power
filter (in matching chassis) has one switch in front, solving the power switch
problem. So a complete lineup would include the power filter, phonostage, dac,
linestage (with remote), headphone amp, and SET monoblocks. Prices would range
from $1k to $1.5k each retail. Super easy to build.
You know what, maybe a line of DIY cables is needed for this. With RCAs in
front, you can't have big loops drooping all over. You want tight and direct
connections. Cut to the exact length you need. Then burn them in with a
FRYBABY. But I don't really want to get into the cable business.
Hey, interestingly, I think these units will stack quite nicely with a two-pole
rack. Same as I did with CONSTRUCTOR series. Would need V2 fins at bottom for
stability.
Doh! What was I thinking? Why not just use a 119DA for the 2A3 output? It is
so simple, just use two of them! Connect the 8 ohm outputs in parallel, the
primaries in series. It makes an almost ideal 2400:8 composite tranny. And
each core can handle 12 watts, so this looks like a stellar solution at less
than half the price. Best yet, it fits inside.
Jul 19
------
Speaking of patents I never got. That UltraGraph was a brilliant idea. They
don't happen that often. Also tied into that were a rotational slit for
imaging through a microscope (center gets more info, hence better resolution
and SNR), and the side-looking pushbroom method. Whatever.
Ultragraph
Meanwhile, thinking of more future projects that might fit into the new
CASTANET chassis. How about a 2A3 monoblock? Once again I am loading myself
up with more work than time permits. But hey, I get excited about this stuff.
News flash! Sounds like there will be a VSAC'08. Memorial Day weekend in
Portland. Now that might be a show I wanna do.
Jul 18
------
So I was thinking, just how much of my sales are in half-kits? Usually I plan
on selling new products in both forms (the difficult ones with custom parts are
assembled only). I did a quickbooks report on last year's sales, and here is
the breakdown in revenue.
Sales breakdown
Yeah, that's where the bucks come from. And why I'm investigating the HAGLABS
business. In a way, it's the only way I can bring in enough revenue to pay for
all of the development costs. Designing and selling half-kits is not really a
profitable business. Unless you strike gold, like the BUGLE or HAGUSB. They
were simple and quick to develop, and sell like hotcakes.
Jul 17
------
And so I see the TXS0102 from TI, a logic voltage level translator, works open
drain bi-directionally. Big ad in EE Times. Both Maxim and Linear Tech have
been making these sorts of things for years. Except I beat them to it. Back
when I worked at Nokia I ran into this level translation problem, and came up
with the novel two-transistor trick to do it. Submitted the idea to the Nokia
patent department. They reported back no commercial use or application. That
was twelve years ago. Fine, so I published it in EDN (later someone improved
upon it by realizing the bases could be tied together).
Translator idea
Look who's laughing now. Not me. TI. Nokia also rejected my idea for an H-
bridge FET switching dc-dc converter - that ran backwards! Yes, with the H
topology you can make both buck or boost. What most folks don't realize is
that the symmetry allows it to work in reverse. I still have not seen anyone
do this. My original application was an efficient dc-dc conversion from a
battery to phone power (main logic voltage). Then, to recharge, the wall-wart
provided an external regulated output, and the H-bridge ran backwards forming
a controllable battery charger. Is was deemed unpatentable as the cost of four
FETs was prohibitively expensive. Well, now I see LT shipping such bridge
controllers. Maybe they too will figure out that it works in reverse. Then
there was the multiple cell charge balancing amplifier string. Whatever. I
just get salty when I didn't get a patent for a good idea. Time proved me
right.
On more important things, avid blog reader DS suggested I take a look at Allied
for trannys and parts. They also have a low cost line of stuff to make
headphone amps out of. He's also DIYed several, including nearly the exact
configuration I drew up for the CASTANET. So I will browse the catalog, check
out what they carry for chassis and other parts. Would be way cool if the kit
could be filled with one order.
Ok, here's my first shot at a B+ delay circuit. It tries to do a number of
things. First, I use the two 100 ohm resistors to ground to make a psuedo
center tap. The winding needs a common mode voltage reference, and this is one
easy way to do it. The 6.3V taps then go directly to the 6H30. The 100 ohm
loads suck off an extra 31mA. I then do a full-wave rectification into a cap.
It can only charge up through one of the 100 ohm resistors, though, so it is
a soft charge dump. And with a load of 2mA there is very little ripple. The
common mode swing on the secondary is then the difference of 30mA/32mA, or
about 0.2V ripple at 120Hz. Not too much harm. Anyway, you end up with a
little under 4Vdc. This slowly charges up another 1000uF through a 20k, for a
time constant of about 20 seconds. That's the delay. However, the transistor
starts drawing some current after maybe 10 seconds, lighting up the LED part of
a solid state photo-MOS relay, sitting on the center tap to ground of B+
secondaries. The MOS does not turn on until maybe 0.9mA, so the slow ramp up
of LED current actually gives a slow-start to the MOS and B+. Not that it
really needed it. Anyhow, with about 2V on the base, the transistor saturates,
thus idling at about 2mA current. This keeps the relay on. At turn off, the
decay in capacitor voltages is about the same as turn on (even though it looks
like it will stay on forever). And that mimics tube action. If you turn the
amp off and then on again two seconds later, there is no need for a B+ delay.
It follows the emission of tube, approximately. Parts are quite cheap for this
circuit and operates silently at low loss. Maybe it needs a 20k from 4V to
ground to reset.
B+ delay circuit
Jul 16
------
Ok, so the CORNET3 is premature. Nonetheless, I like to think as far ahead as
possible to try to not design myself into a corner. Keep as many options and
hooks in place when doing a new design. I screwed myself with the C2. After
VSAC03 I had the impression a lot of folk were asking for a linestage. So I
started the CLARINET project. New chassis, new line, new everything. I sort
of roped myself into the new chassis before I did the CORNET2 prototype. First
draft had the step-ups and hum. They came out after two tries. I was in a
corner and didn't want to start all over again. So MM only it was. That's
just an example. Gotta look to future to see what else might play out. And so
I think about what it might take to doa CORNET3 into this tiny new chassis.
But let's not get ahead of ourselves. Right now I'm not convinced the plate
chokes are going to be good enough. And then there are new sources for hum
induction. Open fram tranny and choke right next to output chokes. What will
get through? And with only one choke on B+ (ripple about 0.1V) there is 120Hz
coupled to output. The choke gives some PSRR, but maybe not enough. Will
output be quiet enough? Next step is to buy parts and wire the circuit up on a
panel. Sound it out. Backup plan is to replace chokes with CCS. However,
they need a lot more supply voltage to operate, which then leads to two power
trannys. It also means I get two filament windings and can fire up a 6X4
rectifier. That solves the delay issue. Where will this head? Not sure yet,
but you have to leave open as many doors as possible. Like making sure the
chassis has just a little bit of spare room.
Jul 15
------
Did some more work on the CASTANET. Maybe that's the wrong name. The "C"
series names are supposed to be reserved for the CONSTRUCTOR line with the
Lansing chassis. Leaning away from that chassis because of cost and the odd
form factor (which was not exactly a hit in the market). Recent examples are
the RIPPER and PICCOLO. New chassis styles. And so I am now liking this box
from mouser.
Chassis style
So much iron in this circuit I have to use the large 9 x 9 x 3 model. And then
things barely fit. But I can use the card guide on extrusions, so tube and
iron on top, other components on bottom. Looks something like this.
CASTANET
Brain is running away. What about making a new line based on this chassis?
Some day I will need a CORNET3. Wasn't supposed to issue it until after the
CORNET MC chassis are sold out. I'd like to make some upgrades to the design,
namely choke input filters and step-up trannys. The prototype CORNET2 had
Lundahl 9602 mounted on-board. However, the routing of connectors to back of
unit past power tranny made for an unfixable hum situation, so the step-ups
came off. Generation 3 should add them back in. And I think I could do it
with this chassis. But only if I cheat and put RCA jacks on front panel and
power switch on back. Would that be ok? Power supply tricks are stolen from
the RGP. It gives me choke smoothing for both B+ and heaters. Nobody else
does that (except the TRUMPET). I like the idea of a very compact and high
performance tube line. Let's see, CASTANET, CORNET3, CHIME2?
Jul 14
------
And so I grab the digikey catalog and sit down on the couch (watching a replay
of the day's tour), to browse through various components to make a B+ turn on
delay. I'm thinking of a timing circuit that uses a thermistor (to mimic the
heating of a tube) and one of those photo-MOS ss relays. After all, I have no
dc supply in this amplifier. Well shux, I can't read the small print. At 47
my eyes will no longer focus at under a foot. Crap, I can't even read the
friggin catalog anymore. At least I can still ride a bike.
300MB per day. That's the average number of bytes that gets downloaded from my
website in 24 hours. Thought you might want to know.
Limiting myself to only ac supply voltages is making this B+ delay circuit way
more difficult than I thought. Nothing is coming to me. Can't use a reed
relay, ac relays start out at 24Vac (in stock). The photo-MOS hold a lot of
promise. Found some NTC thermistors that are big, have 20s time constants
(perfect), and can warm them up off the 6V heater winding. Problem is I need
to drive an LED to turn on relay. I could use two of them back to back, but
then the MOS switches fast and will turn off near zero crossings. That will
cause the inductor to go beserk. One solution is to add a 10,000uF capacitor
to hold LED on for several extra milliseconds. Shoot, this is starting to get
expensive and not clever at all. Maybe a simple rectification to make 7Vdc
supply is a better answer. I was hoping to avoud this as the 6H30 runs an
ac heater. You don't want any harmonics on that signal whatsoever. On the
other hand, those NTC resistors make perfect inrush solution for power
transformer. I'm using one of those Hammond 115Vac types. They run way hot at
120Vac (see CLARION article), so I'm adding power voltage dropping resistors on
the primary. Even better to make them NTCs. This will greatly limit inrush
current to the tube filament on turn-on! Two birds with one stone. I get both
soft power on and the extra 5V drop. At ten watts, the value is nominally 62
ohms.
I'm also thinking now to forget the DAC part of the CASTANET. Best I do not
burden this project with accessories. I think making just a headphone amp is
more useful to the market. What I can do is add standoff mounts for a HAGUSB.
Sure, it ain't the best of analog outputs, but it is suprisingly good when used
as a line out with no load. It will then be optional. I make two analog
inputs with a simple select toggle on front panel. The second input will be
hardwired to the HAGUSB outputs, if installed, which is cool, because then it
turns into an analog output! Your choice. Two analog inputs, or one analog,
one digital. Keep it simple. One power switch, one volume control. Two
headphone output jacks, so the power signal does not have to pass through a
switch. Really, the jack costs the same as a switch, so may as well just have
two jacks. One for low impedance, one for high, different taps from the
tranny. Or maybe I'll have two power switches, so I can dispense with the B+
delay?
Jul 13
------
Thinking of possible ways to reduce cost of this headphone amp. Maybe ss
diodes. Maybe a transistor current source instead of a choke for a plate load.
Then again, maybe turn it into an uber-HAGUSB. Perhaps use a different DAC
chip using PCM2707 I2S outputs rather than the analog line out directly from
chip. Maybe nobody wants the digital feed? I do like to offer something else,
not just a copy. I also like a single volume control, really hate the dual
knobs, can never get it balanced right. Hmmm, unless it is a stepped
attenuator. Can also get rid of second choke in power supply if I use SS CCS,
but then I need a lot more headroom voltage in power supply. Goes up to 200V.
I guess the question comes down to how good these chokes are for signals. They
run fine at 120Hz, but what about 10kHz? They might be useless. Ok, so how to
convert my emu-0404 into an impedance analyzer? That would be handy.
Ok, now I'm thinking two analog inputs, one digital.
Did some quick tests on several Hammond power supply chokes I had sitting
around. Pumped in a white noise source to a 1k resistor, then the choke. Read
the signal back on wavescope (frequency spectrum). Hmmm. Just as flat as a
pure 1k/1k divider. Tried a cap. Yeah, that rolled off. Re-did test on
scope using sinewave generator (non digital stuff). Same result. Perfectly
flat response with 5H choke, rolloff only at super low frequency. That's
actually a good sign. Or maybe the test wasn't sensitive enough. Tried a
filament transformer primary. Whoah, dropped off at a much higher frequency.
Can only mean much lower inductance. No ripples or resonances. Maybe these
chokes ain't so bad afterall?
Customer just reminded me the headphone name was CASTANET. See blog 09/05.
Hey, what about an iPod dock? Or at least a small stereo input jack on the
front, so any player could be quickly attached.
Spent all day on this. Twisting and turning, going left, going right, trying
all sorts of combinations to find some synergy. Since you can just specify
exactly what you want, you have to adjust to fit items on the shelf. Decided
against the CCD. Found this 261C6 power transformer. Small, lower cost, fits
on the inside. Only problem is that it has 1 amp of heater current. So I then
nixed the 6X4 tube rectifier. Don't want the expense of a second or larger
tranny. The found a nice 9H choke that's only $10. Ended up pushing 6H30 down
to a 90V, 15mA operating point. It's a sweet spot, but clips at maybe 40Vrms.
That should be ok for a headphone amp. Adding up all voltage drops, everything
just fits. I use the 30H choke for plate load, parafeed. Measurements earlier
today say it will work fine. Famous last words. But I prefer this simple mode
of operation. I get constant current super-linear operation out of the tube
with a pretty good signal swing. Supply voltage gets to be low, so dissipated
power goes way down. One compromise here is my choice of 1.5uF for the signal
coupling cap. With Grado headphones at 32 ohms on the 4 ohm tap, that reflects
about 5k onto the tube. The tube is somewhere 600 ohms to 1k. That gives us
a rolloff of about 18Hz. Not super low, but reasonable. We also have rolloff
from the output tranny and from the plate choke. So reality says there is no
point trying to push it. Hey, it's way better than what you get out of a
125SE. I stuck with the 1.5uF because it is the largest value AES carries in
the auricap line.
CASTANET circuit
Now I have to think about mechanical configurations, chassis design, control
layout, etc. Also looks like I might be able to do this all with AES parts, no
need for DigiKey. But that's a limitation I don't need to impose.
Jul 12
------
He was right. At my forum I asked what would be wanted in a headphone kit amp.
Opamps, discrete, what? The answer was you wanted tubes. Yeah, I been hearing
that for how many years now. You're right. There is a hole in my product
line. We do need a low cost tube headphone kit.
I'm in the middle of my R&D hiatus, working mad helping out a friend write a
technical proposal. Driving me nuts. Ready to get back to design.
And so I started actually thinking about this tonight. First time in years.
I have no idea what else is on the market right now. I never visit head-fi or
whatever that forum is called. And so I think I'll keep it that way. Usually
I research the market, check out what other folks are doing, dig into their
designs. Figure out what I shouldn't be doing. But I'm going to approach it
differently this time. I'm not gonna look.
My first idea is to do a one tube machine. Just a 6H30. I can't think of any
other tube that has this sort of low output impedance. And I'm already
familiar with it, with a few in stock. Two channels, one tube, single-ended.
Not a cathode follower. So now I just need to find a suitable output tranny
(which I never could before). Might have to go parafeed if it can't handle the
20mA dc bias.
So I open the AES catalog (hey, that's where half-kit parts come from). Nope,
nope, nah. The 125SE? Heck no, it has no bass. Then I see this Collins Radio
replacement, the 119DA. Hmmm, this is just about right. Hook it up with 4
ohm output, 12:1 turns ratio. Yes, this might just work! Add a 369EX power
tranny, a dual choke supply and we got it. Oh, I bet this needs parafeed.
Ok, 30H choke in anode. Then 2uF to 5uF coupling cap. Run simple cathode bias
with no cap. Volume pot on input. That's it. Just a few parts, each piece of
iron is not very costly or large. Easy to mount. Ok, how about a 6X4
rectifier? This is starting to look like the 6922 SIXPACK (oops, name taken)
preamp I designed a few years back. Oh boy, 6 pieces of iron, two tubes. The
chassis may not be very small. I'm thinking this time to put all iron inside,
only tubes stick out. Much easier to build if iron bolts to the circuit board.
Then you guys can play with coupling caps.
Headphone circuit
Hey, what if I add a HAGUSB circuit? Then there is both analog and digital
inputs. Power switch, volume control, input select. One headphone out. Oh
shoot, what am I gonna call this thing?
Jul 11
------
Thought of another half-kit, a remote controlled volume. Heck, maybe a new
remote controlled preamp, based on the JFET stuff I just did?
Jul 10
------
Holy crap. I can't believe it. The credit card company believed the customer-
from-hell that merchandise was never received. And they grabbed $2.5k out of
my bank account without approval. Sheesh. And that's after giving UPS
tracking numbers with proof of delivery. I guess it pays to lie your ass off.
Updated HAGCLOCK manual for operation at 27MHz. This is useful for DVD and
other universal type players. Switched to the MAX913 comparator, which is a
tad faster and helps to preserve duty cycle at the higher rates.
You know, I'm also contemplating a headphone amp half-kit. Solid state,
anyway. Just mulling it over. I'm doing a lot of "what if?" scenarios and
simulations lately. Like what if there is a hurricance that cuts off my
supplies and shipments for two weeks? Or what if I have a hard drive failure?
Most of these I have covered. Today I am thinking, what if I don't do the RGP?
What is fallback plan? Ok, so let's think of what my next half-kits could be.
I could turn FRYBABY into half-kit. Then there is the headphone amp. But I
think maybe the most popular would be a C3. That is, a CORNET3. Hadn't
thought about it until today. Merely pondering what it would be. It needs
a new chassis, but what style? Maybe it includes spots for Lundahl step-ups.
Or is a PICCOLO-like circuit built-in? Does it use 8-pin tubes? Or merely
accommodate both 8 and 9 pin types? Regulation? How to make it better without
sacrificing all of it's inherent elegance and beauty? Knowing what I know now,
how would I do it differently? Can't hurt to mull this over a bit. It can be
plan C, if plan A and plan B don't pan out. Hey, maybe a BUGLE2? Yeah, I'm
getting anal on planning.
Made me a new ad for audioXpress. I've always been a fan of the magazine. I
used to run ads pretty much continuously. Now, I think I'll do maybe one or
two per year, just to be noticed. It's been awhile since I paid for one, so
many of the readers do not know of the RIPPER or PICCOLO. I'm no marketing
expert, but I'm guessing the exposure is good. Internet forum shilling isn't
enough.
New aXp ad
Jul 09
------
Doing some accounting here, adding up all sales so far this year. Wow, much
higher than I thought. Sales are up at least 40% this year over last. And
double that of 2005. So I gots nothing to complain about. HAGTECH is re-
organized, cleaned up, and running smoothly. Taking this month off from any
new development, and then a few weeks more in August for family vacation. I'll
then be refreshed and ready to tackle the new assignments. At the moment the
plan is to move forward with the prototype design of the RGP, reference grade
preamp for HAGLABS. But it is so unique and innovative that I might close this
blog during construction, as I would otherwise give away too much proprietary
information. It's just my nature.
Meanwhile, working on a new aXp ad for PICCOLO, RIPPER, etc. Yeah, I said I
wasn't going to do anymore. Maybe one ad per year, just to keep in the loop.
Probably a lot of newer subscribers that haven't heard of us. I think I can
do this because most of the readership saves every issue! These mags do not
get thrown away, but stored for later reference. That means my ad stays alive
and relevant for much longer than normal.
Now the customer-from-hell is claiming he never received the machines. Sheesh,
and this is after UPS computer records show delivery. Well, good thing I saved
the return boxes, as I just scanned in the labels - written in his own
handwriting! Delivery confirmation numbers and all. I'm just dumbfounded at
the lies people will resort to. One after the other. And this is after I said
I would refund his money, as soon as the fraud investigation was closed. But
no, instead he re-opens it.
Jul 03
------
Got the translation for the Audiopul's FRYBABY review in. Posted online.
FRYBABY review
Jul 01
------
More time painting today. Doing the entire upstairs of the house. Isn't there
a flat wall in this house? It's all so 3D. And with several colors in the mix
that means a lot of taping. At least I got good at it. But I don't want to
bore you with that stuff. Maybe I should tell you about the customer from
hell instead. Nah.
Cleaned out file cabinets today. Tons of old design info. I kept junk going
way back. JIMDAC schematics, the original CLARION, even VACUTRACE pencil drawn
schematics from 1994. So I made a folder of musuem pieces. Handwritten and
drawn stuff from early projects. Like the PD-1. That was a great layout. I
threw out about 70 pounds of paper. Rule #2. Get rid of as much crap as you
can. Hey, it worked in my garage and living room. I'm spreading the doctrine
to the rest of my life. That means the COMPRESSOR is pretty much buried.
Already experiencing benefits of organization and cleanliness. I'm able to
build machines faster and better now. Easier to find tools and parts. More
space in lab to work. Thinking I should sell my Vandersteens too.
www.audiopuls.hr has a new FRYBABY review online. Except that it is written in
something I can't read. Translation on it's way soon, I think.
So I'm looking over the website statistics. Yeah, getting lots of hits, the
usual. Then I notice a referrer as holgerbarske.com. Who? Looks like a
german site, they very kindly put up some info on the ARCHIVER. I wonder if
this is a mirror site to 6moons. For the past few days, here are some of the
more interesting referrals (many left out):
google 440
holgerbarske 117
diyaudio 98
audiocircle 83
audioasylum 67
enjoythemusic 46
head-fi 40
6moons 37
audiopuls 27
audiogon 25
diyhifi 16
vinylengine 11
sonicflare 10
stereophile 10
audiokarma 6
goodsoundclub 6
vacuumtube 6
Jun 29
------
Working on organizing again. Read this "get things done" article in business
2.0 by a guy named allen. Practical stuff. Mostly a way to run an inbox and
reminder notes. Yeah, sounds simple, but could work. I think the idea is to
clear your head from having to use any short term memory. That way you have
less stress, think more clearly (more faculties available to crunch), and get
info at your fingertips. A lot of this I've seen before by other gurus. The
nice part, is that I've been running a similar but more crude system for the
past 20 years. That is, always taking notes, writing down action items as I
think of them. Anyway, I am now trying out multiple lists. Bought me a new
inbox and lots of mini legal pads. If I ever need to know what I should be
doing, I just look at the lists. We'll see how this helps. The lab cleanup
is a parallel effort, but in a way very similar. Two big points from the
article:
1) If it takes two minutes, do it right now.
2) If you haven't used something in awhile, chuck it. Get rid of as much crap as
you can. Live and work minimal.
Jun 28
------
Gee, you think I use too much decoupling?
Capacitors
That's the bottom half of an ARCHIVER. All polypropylene for both signal and
supply. It's a fun machine to build, in contrast to the CHIME GOLD. My
favorite right now is the PICCOLO. It's an absolute joy to build. Also like
the RIPPER. FRYBABY, FRYGOLD, and HAGUSB are then next in line. Great boards,
but then their is some chassis work or wiring.
Oh, regarding the direct mail ad campaign? Not much response. None of the
dealers are biting on the concept of selling cable burn-in time to their
customers. Nordost seems to get away with it, though. Perhaps their
salesmanship is more compelling? Only queries I've gotten back were from those
dealers who wanted to resell the machines.
Made me a couple of 27MHz HAGCLOCKs today. Yup, they work just fine. So now
I'm adding it to the list of standard frequencies. This will be more useful to
the more recent CD and DVD players.
Jun 26
------
Putting together another CHIME GOLD. Sorta getting tired of it, these are a
pain in the butt to contruct. Think I'm gonna stop buying parts for them, just
go with the regular CHIME (which I like better). Made the GOLD versions for
those who wanted the more standard chassis shape and styling. Anyway, I'll
put the ones I have left in stock on sale. Make them same low price as regular
CHIME.
And what's with this terratec thing Fremer is talking about? Shoot, a consumer
grade piece of gear getting the spotlight in stereophile. And this is after I
offered to send them a RIPPER. Maybe I didn't fork over enough advertising
bux. I guess you can't win them all.
Jun 24
------
Been working on some secret projects here. Interesting stuff. But I think I
give away too much info on this blog regarding the innovative circuits and
features. So you have to wait until things get introduced. I can't afford to
have the good ideas copied before I get them to market. Something about that
new korean tube phono that looks awfully familiar...
Maybe I need a summer sale. Not that I can afford to reduce prices any lower.
Then again, must get the word out and advertise.
Jun 21
------
Sales starting to slow for the summer season. Been soldering like mad to try
and catch up. Using this 'free' time to build up stock. Getting tire of
making HAGDACs, they're a pain. Then again, they work every time I fire one
up. A little care during assembly, and it saves a ton of time not having to
debug.
Jun 19
------
My new toshiba laptop came in from ebay. That was fast. Fired it up and she
ran. So here's the real test, I swapped in the hard drive from my old machine,
and up it booted. Looks like nothing ever happened. The CNC is back in
business. Just in time too, as I need to mill out another batch of HAGUSB
cases. Not a bad deal for $50. Compare that cost to the time required to
setup a new machine.
Jun 18
------
Did my last race of the early season yesterday, will miss the big one in July
as we head off to family vacation. Was a good race, my favorite. Last year I
had my best ever performance. This time not bad. Swim was a lot longer (the
placement of buoys is quite random). Usually the starts are a mess, very
crowded with a lot of contact between arms and legs as you try to gain
position. Yesterday, I luckily found myself lined up with a bunch of guys who
all said they weren't very good swimmers. So I took advantage and sprinted off
the line and within seconds was clear, nothing but open water. I was then able
to get onto the feet of the elites for awhile until things got crowded at the
first turn. Anyway, a good swim and T1. On the bike I just couldn't get it
going. A slight upwind and I was barely hanging onto 20. Fortunately, there
was a small hill at the turnaround and I was able to shoot past everyone who
had gone by. Held them all off coming back, but it still wasn't a shining
performance. My achilles heel, actually. Even Rachel caught me with about
two miles to go, saying hello as she sped by. Last year I held her off until
well into the run, probably about a minute or two differential. Then I made
the big mistake. Going into T2 I got lost. Went down the wrong set of racks.
Where the heck was my stuff? Duh. Finally figured it out, but had lost almost
30 seconds in the confusion. During that time, Dustow (a rival) caught up.
Same as last year, I beat him into T2 by 15 seconds. This time, though, I came
out 15 seconds behind. And of course, there is no way to catch him. My plan
had been to bike so well that I had a 2 minute advantage. In reality, my new
race bike didn't go faster, but slower (I have to blame something). So I just
ran a good fast pace to see what happened. Felt good, so I passed several and
pulled my way up the leader board at a 6:36 pace. Finished 27th out of 255.
My age group rankings were pretty typical, 3-5-4. Overall though, my bike was
a dismal 49th. Oddly, I was mere seconds behind the winner of the 40-44 group,
yet I took 4th in 45-49. This year my group is really competitive. So I am
out of the money again with a 4th place. One last race this year, not until
Halloween.
North Shore Triathlon Results
Wow, check out the race between Kim and Uilani (15 & 16)! What I really needed
was a minute faster on the bike, and then no get lost in T2. That would have
made for a great race.
Meanwhile, haven't been keeping good tabs on my equipment out for review. Thom
is listening to an ARCHIVER for me. Getting my CHIME back from Sandy, but no
word from others. I have a FRYBABY in Poland, Levi has one too. Greg chose
his as product of the year. Jones and Dorgay have RIPPERs. Shoot, I wonder
what else I have out there. Oh yeah, Richard has two UFOs. Maybe I push too
hard for reviews? I ask the editors if they are interested, if they say yes, I
send a unit. Sometimes that is the last I ever hear of it.
Going back over my 2007 plan. Right on schedule, I think. Set an ambitious
set of goals to achieve, like a reorganization of my product lines, new
products to fill gaps and expand my lead in certain categories, and to get
financially settled with investment needed for HAGLABS. I am done with all of
the stuff that had to be done before vacation, and that is a month away. So
now I re-evaluate performance and adjust strategy. Some items not selling as
predicted (like the CHIME GOLD), so I must manuever to accommodate. Maybe it
is just a matter of advertising, like with the FRYGOLDs. Anyway, now that the
big projects of PICCOLO and ARCHIVER are shipping, I can relax a little. Time
to ponder an mull things over.
You know, I notice my best selling machines are those that are timeless.
Designs that are classic, that just plain hold up over time. The perfect
example is the CORNET. That circuit came out so good and so sonically
beautiful and flexible (with component choice) that it continues to get raves
today as it did five years ago. Same with BUGLE, VACUTRACE, and FRYKLEANER
(any of them). I need to keep this in mind. I bet the PICCOLO ends up joining
this list.
Jun 15
------
Well my experiment with CORNET chassis colors didn't seem to help. Everyone
keeps buying the blue, I think because of the silkscreen. So I'm removing the
option for various colors. No point going to all that extra work.
Three of the 4 packages arrived yesterday. Maybe the other two got sent parcel
post, which means they are on a slow boat.
Way cool. Remember back in april I went golfing and thought of making a segway
type club carrier? I just saw it in Forbes Life magazine. Not exactly the way
I would have done it, but formidable nonetheless. Only $6k.
Jun 14
------
PC Magazine, I see the new stanton t.90 combo turntable/phono/digitizer. Looks
pretty good. Might not sound too bad. Not hi-end, but seems like they
actually tried. This is going to put a dent in my RIPPER sales.
Got out over a hundred direct mail sales letters. Keep you posted on results.
Jun 13
------
Boy, something is amiss at the post office. I now have 4 packages late or
missing. All at once. What the heck? I paid for the box. Missing boxes are
a VACUTRACE from Canada, A STEP-UP for hum upgrade, an eBay item I bought weeks
ago, and a new address stamp (for those infamous padded envelopes). Everything
is like 2 or 3 weeks late. Never happened before. Wish I knew what was up.
Probably the feds. You mention a word like haunebu on a blog and suddenly
everyone thinks you're a whack job.
Anyway, got my FRYGOLD direct mail ad letter written. Starting to send them
out. Culled a long list of US dealers from various websites. Figure is I
address each one by hand they'll be harder to not open. The personal touch.
Basically, the idea is to have a dealer sell cable burn-in services. Heck, for
$20 a burn, might not be a bad investment. I think a lot of customers who buy
megabuck cables will be into this.
Ah crap, went to use the CNC and the computer was dead. Not booting. Hard
drive sounds ok, screen won't light up. Tried a spare monitor (lucky to keep
some such stuff in the attic), but no go. Removed batterym hard drive, memory,
etc., thinking maybe they just need to be reseated. Nope. Dang, this is the
4th PC I'v had connected to the CNC that's died. It's the salty air. PCs in
the office live long because I never turn them off. Can't. Gotta keep them
warm and dry. So shoot, now I have to get me yet another replacement. Maybe I
can get another Toshiba 320CDT, plug in the hard drive I got and be off and
running. There's a few CNC data files I never backed up, like the HAGUSB XLR.
Any suggestions? I need to run DOS with a VGA monitor and keyboard. Doesn't
even need to be color. Just compact and cheap.
Ok, never mind. I just put in a bid on eBay for a 430CDT. Won without even
trying. I really didn't want to have to think about this. Just fork over the
cash and get a replacement quick. I'll be up and running again with minimal
effort. Plus, think of all the spare parts I got!
Jun 12
------
Oh my, getting behind here on my blog. Did I mention the ARCHIVER production
boards came in? Yup, getting these built up for shipment. Sorry for the delay
to those who have so patiently waited.
Improving another aspect of my customer service. Moving towards "satisfaction
guaranteed, always" (oh wait, doesn't Walmart say "always"?). Next step is to
increase the in-home trial period to 60 days, instead of 30. For some pieces
of equipment, the shorter period just wasn't quite enough to assess harmony in
a system. For unused half-kits, the period will be a year. Warranty will
continue to be ten years, transferrable. If you buy a HAGTECH built machine on
the used market, rest assured that it is still covered. My goal is total
customer satisfaction. We'll help you keep those machines running as good as
new.
Thinking I need to do a direct mail ad for the ARCHIVER. Really haven't done
much promotion, if any. I was going to send a unit to TONE AUDIO for a piece
they were planning to do on 78's and mono LPs. Not sure if they are still
doing it. Have not followed up. Anyway, the real market for that machine is
obviously archivists, those with large mono recordings such as collectors or
libraries. So maybe I start by targeting libraries. Hmmm, how to do that.
There must be a trade journal.
Shucks, I just noticed in my lab cleanup that I still have a FRYPRO2 machine
that I can sell. It comes with a separate power cord (for burn-in) attachment.
Anybody want it?
Jun 05
------
Came across the schumann resonance, apparently something Tesla found in his
beam power studies. The main resonance is 7.83Hz. That's probably the
frequency chosen for our vintage submarine communications link (George Wright
mentioned the transmitter was in Washington state). Interestingly, the upper
resonances were 33, 39, and 45 Hz. If you double the 39, you get 78. Is there
some sort of connection here?
Jun 04
------
Wow, I don't get it. All of a sudden, like 2 days ago the amount of email spam
I normally get dropped by a huge margin. I wonder if my ISP improved the
filter? This is great. The total is now about 1/5th of what it used to be.
Cleaning up the shop. Been a year since I moved into the new space, and have
not done much to keep it organized. I got crap everywhere. So many projects,
working and abandoned. Parts galore. Protos, chassis, boxes all over. Trying
to consolidate. The area has become rather inefficient. And that is key to
good production. Manufacturing processes must be organized. This is part of
the reason why I always end up with part shortages. Been too hard to keep
track of inventories. This might take awhile. Adding more cabinets.
I think I'll make a newsletter/ad for dealers. Yeah, target audio dealers
directly with a letter campaign to promote the FRYGOLD. It was designed for
them anyway (or any power user). The idea is to have them buy one unit so they
can offer their customers direct burn-in services. Heck, why not charge $25 to
break in cables? I bet there would be good ROI. Anyway, so now I have to
scribe a new ad.
Oops, somebody noticed I forgot to put in the reference designators in the
PICCOLO manual. Fixed it.
Jun 02
------
Kids finally out of school. Lots of stuff going on in these last few weeks.
Like the big graduation from kindergarten. Good news is that I am relived of
my morning commute for a few months. That gives me more time to concentrate on
R&D.
Meanwhile, wrote the "assembled" version of PICCOLO manual. Madly building
equipment to keep up with demand. I keep finding myself short on inventory for
one part or another. Always grinds things to a halt. But the problem is also
the solution! That is, the problem is that I have so many active products at
one time that it is supremely hard to keep every single component in stock (it
numbers in the thousands). However, having so many products allows me to shift
production from one to another at the drop of a dime. It looks confusing, but
I manage to build 5 or 6 various machines all at the same time, bouncing from
one to the next depending on conditions.
Also been a little sidetracked by some cool stuff I found on the net. You
never know what you might stumble upon! Do a google on "haunebu". Fascinating
information. Probably a hoax, but the connections to known real life is almost
overwhelming.
May 29
------
Finally rode my new old bike. That is, new replacement road frame. Wow,
nothing like getting the size right to improve comfort and handling. This bike
rides like a dream. Very comfortable and quiet. Superb handling, very
confident and maneuverable. Not like the unstable tri bike. Enjoyable ride.
Now I have one bike that goes uphill, one that goes upwind.
Updated manuals. Fixed those pesky little part number changes that keep
popping up the forum. Fuses, beads, LEDs, switch, heat sink, usb cable, etc.
May 25
------
Just ordered production ARCHIVER boards. And the old style 2SK389 are en
route. That settles the ARCHIVER / ARCHER issues. Machine is ready to go. I
shall take you order now. Meanwhile, curious to see how the first batch of
PICCOLO half-kits are doing. Fun little project. Need customer feedback on
any mistakes found in the manual.
Got the online photo samples in from the last race. Here I am running down the
finish line chute with my two younger ones (had to let them pass me). Not too
shabby form after 2:24 of full effort. Upright, shoulders kinda back, foot
strike nice and flat underneath the knee.
Hono Tri finish
May 24
------
So I finished building another TRUMPET. Yeah, had the parts laying around,
boards already built. Fired it up and connected stright to the Dyna. Wow, it
still shone! I was expecting way too much noise, but it really wasn't too bad.
On the Time Out LP the noise floor or recording was higher. The combo was very
listenable. Which I did. Even at 47k loading, the cart held on to control.
Sure, the top end was a little flappy and pronounced, but not harsh. The
cymbals were just a little disconnected from the rest of the music. Mostly, I
remember now that the TRUMPET is indeed quite a step up from the CORNET in raw
sonics. Just more open and refined. Less veil. And I hadn't even burned in
this machine yet. I'll with PICCOLO when I get next one built (ran short of
parts again).
I changed my mind regarding the ARCHIVER. Just looking at what I have to do to
relayout this thing, it would be insane. Don't wanna go through it. Mainly,
one of my customers noted that www.blue-staronline.com had some in stock. So I
bought another huge batch. Costs twice as much as the surface mount ones from
LS, but it keeps me from having to relayout the dang board. This helps me get
into production quickly. I should be able to pump machines out in about two
weeks. No more delays or aggravation. Besides, the layout was such a piece of
art. A seriously beautiful chunk of craftsmanship. This strategy allows me to
produce in small batches without too much up front investment. I'm really
trying to clean up my act here so I can start concentrating on the RGP design.
May 21
------
Bought various shims at the hardware store. Found a "C" washer just the right
size and about 1.5mm thick. Put it under the RB300 arm and it now looks like
VTA is very close. Visually. At least with the stock felt mat. And the
cueing lever works.
Big race of year yesterday. A bit sore today. That's what undertraining does.
Really had to push hard into the pain zone to keep up. Problem is, the timing
chip fell off during the run. I didn't notice until the finish line. Thought
it was odd that on second loop of run I didn't hear the timing beep. Dang.
And then I got a drafting penalty. But shoot, not much you can do when you
come up on a slow group. I was one of the last waves to start, so had to swim
through an obstacle course. The problem was the also ran a sprint distance
race at the same time, so the faster bikers would come up on them from behind.
I was amid several rivals at the time (one who was definately drafting) and we
were moving good, but catching up to slow groups. We end up bunching as there
was not enough lane to get around. And so the race official kept watching us
and taking down numbers. Not our fault! Give us some lane so we can pass.
Anyway, it was an ok performance. So many top-notch competitors, I ended up
mid pack with a 2:24:44. Good thing I had my own timing watch. Seaver caught
me late on the run, but I was out of gas and could not hang on. I let Sawai go
by so I could run the gantlet with my kids. They liked that part, sprinting to
the finish line with the announcer and crowd cheering. Best I can decode times
is 28:30 swim, 1:05:30 bike, and 47:00 run. Pushed as hard as I could, but the
run never really got up to speed. Last year same course was 2:27:00.
Honolulu triathlon 2007
May 18
------
Ended up reinstalling acrobat. That seems to have done the trick. Had to also
copy over all my music files, documents, favorites, etc. from dead account to
new one. So I think I'm pretty much back online. Wow, this is one great
reason to keep data separate from operating system. Fortunately, I have
backups of most of my critical design data spread across several machines and
even uploaded some of it to secure places on the web. All except for my
emails. Doh! Had no backup. Luckily I found the old dbx file. Also looks
like most of my program defaults have been wiped out.
Anyway, did some more work to website. Making the CORNET available in two
flavors, the original MM and also the MC. Was getting requests for the non-
PICCOLO version. Ok, your wish is my command. I can build either.
May 17
------
Shipped out the first PICCOLO today. Wrote a first draft of the ARCHIVER
manual. I think I'll add the ARCHER stuff to it.
ARCHIVER manual
My old computer has been slowing down over the years. So I bought and
downloaded the pctools registry mechanic. Ran beautifully. Machine is now
clean again. However, it no longer has any resemblance to what I had before.
All of my icons are gone. My entire email setup is gone. My entire account
is wiped out. If anything, I just want my emails restored. Drat.
Ok, dug through and found my email files and addresses. For some reason the
registry fix created a new account for me. Can't get to old account, so just
copied the database files to new one. Seems to be slightly working. Nothing
seems any faster than it was. Been having lots of problems with adobe pdf
lately. Crashing. Didn't get it fixed.
May 16
------
Just got notice that PICCOLO boards are on their way to me. I can start
shipping out half-kits Monday.
Wrote a massive upgrade to the online order form. Although it looks exactly
the same, I added a ton of new code. Ok, not good code, but the brute force
inelegant type. But it works. I think. It is now set up such that options
are nulled until a non-zero quantity is entered. Then options light up as they
become valid. Hopefully this is slightly less confusing. It also greatly
improves things on my end. The cgi scripts I have running used to send me way
too much unnecesary data. Now it only sends the important stuff.
May 15
------
Ok, so the feedback from Thom is quite positive. Independent listening tests
of the ARCHIVER are proving fruitful. So it gives me the green light to go
ahead and invest in production parts. And it means the ARCHER is just as good.
So I added that to the website today. In fact, I actually have one in stock
ready to sell (ARCHIVERs will come later). I'll price it at $949.
ARCHER
I also re-organized (slightly) the menus and order of products. Changing the
"industrial" to "professional / studio", as many of the newer ones are rack
mount style and perfect for studio or theater type settings. In fact, the
ARCHER would make a perfect DJ phonostage. Very rugged and reliable. Perfect
for the road. I made this studio category just in case I want to issue the
COMPRESSOR.
Then I did something wierd. I put the TRUMPET back on the index page, right at
the top where it used to be. Yes, it is still discontinued, but I'm wondering
if I can use it for credibility. And yet I built another out of spare parts
today. So now I have two TRUMPETs on hand. One for the museum, one for?
May 14
------
So I whipped together this new TONE audio ad in about an hour. Just not enough
time to make it look totally professional. But it gets the idea across. The
previous ads were focused on branding. This one is for controversy and
attention. So is it over the top? I think each claim is defendable. Wanted
to make it clear that "world class" is not limited to large companies with big
budgets. When it comes to innovation, we can compete too.
TONE audio ad
Had my first race of year on Saturday. Not too much rust. A decent finish,
but certainly not spectacular. Should have been good enough for a podium spot
except some new guys aged-up. At least I made the front page. A little slow
on the run, big hill slowed me down. Mostly I am disappointed in the bike.
Spent two grand on a new racing machine and I don't think it made any
difference. Not really a time-trial course though, as it had a lot of turns
with only a 1 mile section of out and back straightaway. We'll see if bike
does better this weekend at the big race. No more warmups.
Race results
And so I spent some time tallying up the last six months or so of order form
data. At the bottom of form I put in a selection list of referrals. Or where
did you hear about us? I want to examine the cost effectiveness of advertising
in various spots. What works? Here's the summary.
Who referred you?
Some things really stick out. My favorite online audio magazine TONE audio
came in dead last with zero. I spent more cash here than anywhere else. Full
page color ads. They were fun to make. What else do you see? The big online
e-zine sites of positive feedback, enjoy the music, and 6moons did not score
too well. I can't complain, as they're freebies. AudioAsylum trounced
AudiogoN. But maybe not in dollars. That's something I didn't account for.
It seems to me the clientelle of Agon has more bucks and are not interested in
DIY. So making a lot of noise at both of these sites is critical. AudioXpress
scored very high and I haven't advertised with them for maybe a year or two.
How can that be? I think maybe a random ad every now and then might be a good
idea. Lots of DIY folk there. Google does well. Now if I could just tell if
it is from random searches or because of the cash I spend on adsense.
May 09
------
Finally got the first draft of the PICCOLO manual done. Includes parts list,
schematics, everything.
Piccolo Manual
Working on a new ad. A bit audacious, but I think reasonably defendable. It
goes something like this...
world's best vacuum tube phonostage under $1000 (cornet mc $999)
world's best vacuum tube dac under $2000 (chime $1799)
world's best vacuum tube tester under $2000 (vacutrace $1249)
world's best mc headamp under $1000 (piccolo $299)
world's best phonostage under $200 (bugle $129)
world's best digitizing phonostage under $500 (ripper $399)
world's best cable burn-in conditioner under $500 (frybaby $249)
world's best reference cd clock under $200 (hagclock $99)
world's most flexible phonostage under $2000 (archiver $1199)
world's coolest strobeclamp under $1000 (ufo $399)
May 07
------
The Sandy Greene CHIME review is now up at SonicFlare.
SonicFlare CHIME review
Meanwhile, I installed the DV-20XL yesterday. Got it all aligned with the
protractor. But it seems VTA is way off. Played some tracks. Hmmm, not the
big leap forward I expected. A little thin. Oh crap! I forgot to rebalance
it. I must have been tracking at 4 or 5 grams. Duh. Ok, squared that away.
Still a VTA problem. This is one tall cart. The lifter can't even take the
stylus out of the groove. I need to raise the arm 1 or 2mm. Any ideas? A P3.
Sound is now much better, giving me a much clearer presentation. Even with VTA
messed up, this ain't bad. Dynamics aren't quite there, but it remains fast
and suprisingly nuetral. Tone is clear and bass very articulate. At least in
comparison with the Goldring 1042. The important this was the compatibility
test with an ARCHER. Noise floor is way down. This is something I always
worry about. But it was spectacular. Ran at 65dB gain. The change in loading
didn't make as much of a difference a I expected. The changes between 50, 100,
and 220 ohms is quite subtle. Maybe it's a headphone thing. I liked it best
at 100, although 50 was a tad more organic. Top end really didn't get rolled
off that much. At 47k it was screaming. Seems to me anyone running an MC into
47k is likely deaf.
Wow, Mercury 66 limiting amplifier, $6.5k. Shoot, and it's only one channel.
Dang, I need to get the COMPRESSOR back online. Or how about the Millenia
Twincom at $3.5k. Now that's more like it. Very similar to what I did minus
the mic preamplification. Still smoldering.
May 04
------
Here's a better shot of the ARCHER. Not sure what to do with this. Could make
it an option for sale. Maybe I just keep it for myself? Did this one in
silver. Looks quite good. Got it burning in now. You can see the open frame
style chassis. Circuit board is sandwiched between two aluminum panels. Very
solid. Also, my LOMC came in, so I can rig it up this weekend. Can't wait to
hear it!
ARCHER frontARCHER back
May 03
------
Refocussing on real work. Trying to keep myself from getting sidetracked. A
good example was the PICCOLO-BUGLE combo I started to work on. Nice project,
and it was the reason I moved mounting holes on the PICCOLO (to make sure they
lined up). But taking too much time and money. Especially away from revenue
generating projects. So I ripped it up. If it isn't directly contributing to
the bottom line, I need to move on. So much real work to be done. Converting
the boards back to their original purpose. Anyway, I'll post some photos here
to show how such a project can be done.
PICCOLO-BUGLE frontPICCOLO-BUGLE side
May 02
------
Finally got the design and label squared away for the HAGUSB XLR, the AES
version with 110 ohm male XLR output. Works just like the original, but in a
slightly larger box. Using the headphone and XLR jack from FRYGOLD inventory.
HAGUSB XLR
May 01
------
Didn't get much done last week, too much ballet and other kid stuff. Anyway,
finished painting several CORNET MC chassis with my new color choices. They
came out better than I expected. They look really good. I bought the most
expensive spray paint I could find. Colors were limited, so I picked out the
almond (off white), red (more of a firebrick), and black. Hopefully this will
allay the complaints of those who don't like the blue.
CORNET MC chassis colors
ARCHER panels came in, so building up that proto. Just loading, gain, and
output polarity. A straightforward phono built using the ARCHIVER circuit
board. I think maybe $899 or $999. Will have to add up costs. Probably
custom order only.
Apr 26
------
Major price reductions! I dropped prices on everything (except the CHIME,
which was too low already). FRYGOLD and RIPPER down by $100, back to where
they were supposed to be. I even dropped price on some half-kits, like the
CLARINET to $89. PICCOLO went down to $299. HAGUSB down to $119, plus I'm
adding a new XLR (AES) output version. Adding new chassis paint options for
CORNET MC and upgrading output caps.
Ok, call me a geek. But in the interest of market research I spent a half hour
adding up all of the ages in the audiogon forum questionaire. Almost everyone
is in their 40s. This is an interesting poll, as it requires users to be
computer literate, online savvy, and egotistical enough to actually type in an
answer. What do you think? Does this really reflect the actual population of
audiophiles? There were only 3 of 304 responses over 60. None under 20. I
don't think this follows the boomer trend. Does it follow an income trend?
Why the abrupt fall-off over 60? Is it because guys lose their hearing or at
that age don't use computers? The good news I see is a LOT of interest from
the younger generations, between 20 and 35.
AudiogoN poll results
Apr 25
------
Did a quick compare of the OBOE and ARCHIVER. Wow, I thought the BUGLE stuff
was good, but in comparison, the ARCHIVER is so much smoother and less harsh.
And whoever called a BUGLE harsh? I think I'll record some tracks comparing
the RIPPER to ARCHIVER. They both have the same digitizer, so maybe the
slowness (or is it just naturalness) of the latter will come through.
Ok, I did it. Yeah, this is one of my test tracks, as it is recorded hot and
has some stampeding dynamics. Easy to overload something with this track. I
had to really turn down the level controls to keep the meter from pegging.
These are large uncompressed raw WAV files of less than a minute each.
RIPPER testARCHIVER test
Personally, I like the latter better. Just plain easier to listen to and more
enjoyable. Recordings done using Goldring 1042 MM cart.
Making final tweaks to PICCOLO board. Moving some decoupling caps about 1/10"
to make room for teflon washers to mount over RCA jacks (purely for external
appearances). Making pad size on ground hole larger, and I discovered the RCA
jacks don't sit in the holes per data sheet. The centerline gets shifted about
0.025" towards the outside, thus not centering them properly into the box. I
will fix this. Also noticed the jacks don't lie perfectly vertical. The
bosses on bottom are not equal. The jacks tilt slightly outward. Not sure
what I can do about this. Will order production boards today.
Also starting manual. I am so far behind on this project. What a mess of
hurdles it has been. Anyway, final prototype powered up fine and sounds good.
Apr 24
------
Lots to do today. Got PICCOLO boards in, the LSK389, the CS8415A, and several
other parts orders all came in yesterday afternoon. Gotta get a bunch of
machines built and shipped first, but then can work on the production PICCOLO.
Ugh, that means another assembly manual. Thinking I'm going to send the
ARCHIVER proto to Thom for some unbiased listening tests.
Meanwhile, made up a proto of the HAGXLR, an AES output version of HAGUSB. I
think this will sell. Bought me a larger version of the same case, so board
mounts properly to the bosses, with room to add the XLR. Will also have to use
a panel mounted jack for headphones. Only a slight shaving of the board is
needed to fit. The ony thing I don't like is that there is a battery door on
the back side. Anyway, make a new label and I think this is ok. Might try
another box.
HAGXLR proto
Customer called today asking about the CORNET MC, and does it come in anything
other than blue. Hey, why not? The hard part of painting aluminum is the base
coat, and it is already baked on. I think I'll get some hammertone colors
tomorrow and spray up a few chassis. Then you can choose your color online.
Only the blue, of course, will have the silk screen.
Learned the hard way (again) that pricing a product is very unscientific and
prone to the ever changing whims of the marketplace. Latest example is when we
put THE RIPPER into the music direct online catalog. Since it was designed up
front to be sold factory-direct, I had a real hard time pushing the OEM cost
down. In fact, it went to a point of zero profit, just a break-even point
where the benefit would be from the extra media exposure and brand recognition.
Well, at the $500 price they stopped selling. At $400 I was building them non-
stop. That's the magic pricing. One point is fine, a little higher and forget
it! So we talked it over and decided to drop it from MD. They'll sell off
their stock at reduced pricing.
And speaking of pricing, I'm going back the the "9" method. No more rounding
to the nearest "10". So $400 machines will go to $399, etc. I have to admit,
but this trickery actually works. So I will revisit all of my pricing, see
what can go down or up. Reverting back to factory-direct on everything except
the FRYBABY. Probably will drop the FRYGOLD way down to $399 also. Way down.
That too, is a magic price point. Everyone who bought at the $500 price will
get a refund. I'm looking ahead here, and predicting the market will soften
over the next year. So I'm going to get aggressive now.
Apr 23
------
Did some more measurements of ARCHIVER. Bandwidth from 15Hz to 350kHz. No
problem with top end there. Gains were spaced 5dB apart, not 6dB as planned.
But it works out ok. Can't stretch any more gain out of this thing. Getting
70dB for low output mc and 45dB for high output mm. Output level is left
intentionally low to match the digitizer onboard. Still, at 0.5V output
single-ended it has a low 0.05% distortion level. It starts to rise a bit
above that, clipping at maybe 3V. Distortion at 1V (2V differential) was
0.24%. Keep the gain down and it sings. In operation, this is the quietest
phonostage I've ever used. Noise floor is way down. Yet the numbers don't
look so good. Got 66dBA referenced to 500uV input (60dB gain setting) and
loading at 100 ohms. This is where most MCs will be used. That's 0.25uV
input referred noise. Or 1.8nV-per-root-Hz. Now keep in mind the flexibility
in reporting this parameter. I could have said referred to 5mV input, which
would then make it 86dB. Or relative to maximum output to make it 86dB again.
Easy to disguise. Don't compare phonostages by their numbers! Apples and
oranges.
Apr 21
------
Should have waited for the ARCHIVER to burn in. Stupid to listen with raw
caps. It opened up another level, a little closer to the tube glassiness. A
bit more clear and clean. Still slow and throaty, but it's not bothering me.
Just a different presentation. I'd say unaggressive. This stage is not in
your face. Very polite and natural. I really need to get my MC cart
installed.
Apr 20
------
Wife is out of town, so I'm shuttling kids all over the place. Dance recital
for school is coming up, so they rehearse almost every day now. Big production
of maybe 200 kids. Anyway, the theater is really old and cool. Very retro.
Obama performed there. They still use some very large JBL speakers with a
friggin huge compression driver on top. But the sound really sucks, as they
drive it with an old transistor amp. One of these days I have to volunteer to
fix that. It is screaming for some tubes to tame those things. I think I can
turn that place from ear hell to paradise without too much trouble. All I have
to do is swap in a CLARION and I bet it magically transforms. Ok, they need
more power than that, but it will make the point. I'll be a parent at this
school for at least another decade, so I have time. Just need to insert myself
with the right people.
Had shipped the first FRYGOLD to Finland. When it got there the acrylic back
panel was shattered into a million pieces. Hmmm.
Apr 19
------
Finally had some time to finish building ARCHIVER #2. Kept forgetting parts,
must have pulled it apart five times. But it came out with no wiring errors,
and near perfect EQ. Super quiet too, but I guess I mentioned that earlier.
Need to run some tests, distortion and gain. The sonics were really cool. I
was a little taken aback. It did not have the glassiness of a tube stage (it
is not broken in yet), but neither did it have the staleness of solid state.
It was anything but cold. The music seemed really slow and relaxed. Nothing
was exaggerated or emphasized. I had to check the TT with a UFO just to make
sure it was spinning fast enough! Warm and throaty, I don't understand why it
seemed slow, this stage has a megahertz of bandwidth. There was no loss of
treble either. Very listenable and no fatigue. Great noise floor. Maybe the
sound was a little more fat than I am used to.
Also found me some CS8415A. On order and should be here in a few days.
Read a comment by Dvorak (pc mag) that with the proliferation of wall-warts,
they should be labeled appropriately. Rather than just Xinghua or whatever.
That makes me guilty too. I think I should make some labels for these that
go with the FRYBABY, etc. That way you always know what plugs into what.
Apr 18
------
Ugh, now I find no stock anywhere for the CS8415A used in the HAGDAC. Better
check pinouts to see if I can upgrade to the CS8416. This sure seems to be a
recurring theme with me. RoHS changes, obsolescence. Manufacturers pushing
new parts. You have to be really careful when using older chips in a new
design. Most of the time it is ok, if you use jellybean parts like an LM358
ot LM13700 or CD4001B. Somebody keep making these forever. But I got nailed
with the ICL8038 function generator on original FRYKLEANER. I expect problems
soon with the critical PCM1704 24-bit R2R converter chips. Probably the DF1704
too. And then the 2SK389 debacle. Maybe the PCM2906 used in THE RIPPER? I
think this is why the big names in the industry come out with new machines all
the time. It's not just marketing, but a matter of chip availability. Have to
keep using the latest and greatest in smaller and smaller packages.
My Dynavector 20X came in. But it was a high output version. I need the low.
Must send back for exchange.
Apr 16
------
Got a sample of the PICCOLO box in. Looks fine. Now they can do the entire
batch and then silkscreen them. Probably be here before production boards.
Actual knobs will likely be a smaller diameter.
PICCOLO box
All sold out of the CORNET2 "box/2" chassis. Plenty of CLARINETS.
Apr 13
------
Couple product ideas here. Been getting some requests lately for a HAGUSB with
XLR (AES) output. Well heck, why not? I did make one of these custom before.
What I should do is find a new box that the larger connector will fit. Cut it
out on my CNC. I think this is reasonable. Make an XLR version of HAGUSB for
$150 (requires more work). Other idea is to make a simple version of ARCHIVER.
Remove a bunch of the features and make a plain phonostage out of it. One set
of inputs, loading, gain, and output polarity. Set the EQ to RIAA, leave out
the USB stuff. It's not a whole lot cheaper, but might make for a nice stage.
Started making one today. I can use the same circuit board, leave off parts
and add jumpers. Can't think of what to call it. ARCHRIVAL? Mayber ARCHER,
same phono but missing a four ("IV") knobs.
Apr 11
------
Just saw this quote in forbes by A. Einstein: "Intellectuals solve problems,
geniuses prevent them." Why can't I possess such conciseness? I think it's
time I read his biography.
But for now, I just read stereophile. Mikey makes an argument about brick and
mortar dealers. They were all flocking to AV and custom installations, but now
flat panel pricing has dropped like a rock and the markups are no longer there.
So they are going back to two-channel and high-end stuff where they can
actually make a buck. Interesting, I wonder how drastic this turnaround will
be. Does it bode well for high-end? I also notice an incredible proliferation
of more megabuck phonostages. Sheesh, $10k is now a bargain. And nobody seems
to be offering anything new. Just repackaged stuff that's already been done.
Man, the door is wide open. I don't know if my RGP strategy was brilliant, or
if the marketplace is accommodating me through some quirk in the cosmic time
continuum.
Oh, I finally got the LSK389 stuff untwisted. Found me a good working
solution. Just need to get it done mirror imaged on the other channel. The
good part is that it freed up some critical space in a specific area that
allowed me to upgrade the decoupling caps. Hopefully I can get these on order
tomorrow. So much to do, so little time. If I were a genius, I would not have
to solve such problems.
Apr 10
------
Ugh, this twisted LSK389 is a pain. What idiot did this? I can't get anything
to untwist and work. Got the PICCOLO layout completely unripped and spent
hours trying to find a solution. It's a mess. The original is so beautiful
and clean. A work of art. The SO-8 replacement is awful. Half a day and I
made no progress. You'd think just 4 transistors wouldn't be so hard. Well,
my layouts are a bit unordinary. They have to be clean. Shoot, if they just
didn't twist the pinout it would have dropped in perfectly. What were they
thinking? I can't imagine trying to do this for the ARCHIVER.
Apr 09
------
Trying to fit the TO-71 LSK389 package onto the PICCOLO board. One JFET is
twisted around, so traces are a mess. Nowhere near the beauty of the original
7 pin package. But hey, if you can't get 'em, too bad. So I'm checking on
pricing and availability of the SO-8 surface mount package. It might be
cheaper. And since they have to be included in the kit/2, it's just as easy
if they're surface mount or not. Looks like they will fit a little better,
but still have the twist problem. So the domino effect puts a lot of things
on hold. Until I get this issue straightened out (package, price, etc.), the
layout can't be done, nor can I order production parts. Which then pushes out
the date for shipping PICCOLOs and ARCHIVERs. Agonizing. I suppose I can
start writing the manuals.
Apr 06
------
My email spam has now hit a ratio of 25:1. For example, I got 122 messages
this morning, only 5 were real. Such is the price.
Apr 05
------
Unbelievable. One day later and the dran laser printer is acting up again. It
spit out a couple of perfect pages, so I thought I was done. Yesterday it
starts dropping toner spots down the right side (fuser problem was on left).
So now I get dots. Tried cleaning mode, various papers. Nothing in the
settings I can find that helps. Any ideas?
And get this, talk about luck. I'm riding the new race bike, and all of a
sudden the rear brake falls apart. Sheesh. Front end got loose last week,
this time a nut falls off the brake. I had to find a piece of plastic string
on the side of the road to tie it off, make sure it didn't fall into the wheel.
What am I whining about? This stuff is manini.
Apr 04
------
Ah crap. No more 2SK389BL out there. Looks like I made a major blunder. Not
even usbid.com can find any! Oh well, ain't the first time I've been stung by
part shortages. Thus, I will be doing a relayout of the PICCOLO to use the
upgraded LSK389 part. Pricing will rise accordingly. This will add another
two week delay to the schedule. ARCHIVER will also be getting the relayout
treatment.
Getting bogged down here with a lot of delays. Still waiting for my Dyna 20XL
cart to show up. Stu still owes me $650 or so for the white cornet. Waiting
for connectors to arrive from jameco so I can ship this 240V FRYGOLD. Not
hearing back from a lot of reveiwers. I have $5k at least in equipment out
there. Some of the FRYBABYs and RIPPERs have fallen into the ether, I think.
Yikes, and now taxes due. The game plan was to get a grip on things and button
up my strategy and loose ends. The tunnel is longer than I thought, not seeing
the light yet. At least the printer is working.
Having trouble getting super clean cuts on that acrylic sheet. I am making
thin 1.7" x 16" panels for the back of FRYGOLD. Not having the best of luck.
Getting close, but too often the break doesn't stay on the score. It ends up
wasting material. Maybe it's just a matter of practice. And another C-clamp.
Gotta write the FRYGOLD manual now.
Apr 03
------
Wow, I almost can't believe it. I fixed the laser printer. None too soon, as
I was not able to print manuals properly. I have a whole new appreciation for
the design that goes into such consumer products. So man mechanical parts. I
had to practically disassemble the entire thing to get to the fuser. Rather
complicated, I got stuck early. Bought a pdf online of the tech manual for $7.
Worth every dime. I had this baby ripped apart in no time. All went right
back together, suprising, since there were two dozen screws sitting in a pile.
I missed only two, so had to pull the scanner off a second time. But in the
end, buttoned it up, plugged it in, and the damn thing started printing docs
that were still in the queue. Like changing toner. I got my baby back in
action for hopefully another 10,000 pages.
FRYGOLD boards came in. So building that up, plus the new ARCHIVER. Meanwhile
no word regarding availability of JFETs. Ain't that a sickening feeling. Just
spent quite a few months R&D on both the PICCOLO and ARCHIVER, only to find out
when you're done and ready for production that you can't get the parts. If I
have to redesign for the LSK389 there will be some delay. I might just take
the risk and go straight to production without a third proto revision.
Have this idea for a new TONE audio ad (I wonder how many issues I have left).
Sort of over the top braggadoccio. The concept is to use a bunch of the better
customer testimonials I have received over the years, put them all in a row to
make like a background. A full page of non-stop text. Then some foreground
copy that is basically "the world's best" attitude. For example, the world's
best tube dac under $2k. Or the world's best vacuum tube tester in production.
Or the world's best cable burn-in generator for under $250. That sort of
thing. Ok, they are arguable, and I don't have awards or industry comparisons
to prove it, but they are not unprovable either. Maybe the CORNET MC is the
best phono under $1k? It could be. The ARCHIVER is the most flexible. BUGLE
is probably the best for $150. PICCOLO will probably be the best headamp under
$500. Impossible to prove or disprove, but still, each promotion has merit.
I've come up with 9 so far. HAGTECH can arguably try to claim world's best
whatever in 9 special (not broad) categories. Seriously, who makes a better
portable cable burn-in device for $250? Nobody. So the question is, does this
type of ad offend you? Does it backfire? I'm actually thinking that maybe
there is some positive result from just the PR generated by the audacity. I
am hoping some jerk on AA posts a question like "who the heck does this guy
think he is?" Or "can you believe this crap?".
Apr 02
------
Checking in on my order for more of the 2SK389 JFETs needed for the PICCOLO and
ARCHIVER. On backorder and they don't know when they show up, if at all. I
bought a hundred several years ago when I first looked into a headamp (but
never really got going). Easy to buy back then. Now, might be impossible. It
is no longer being made by Toshiba. Holding off on production PCB order until
I get some confirmation here. Tried one broker and they have nothing. Trying
usbid.com to see what they got. Could be I have the last few on the planet,
and I just sent 4 of them to some guy in Germany. Crap. I might have to
switch to the LSK389 from linearsystems.com. They cost 4x. That will push the
price of these machines way up. That's almost $50 in just JFETs for the
PICCOLO half-kit! Theoretically that makes the kit/2 sell for about $175. And
I have to do a relayout, as package and pinouts are different. Dang. Did I
make the fatal mistake of designing myself into a corner?
Here's something I don't get. Almost every day I get an email asking me if a
half-kit comes with transformer, chassis, and all other parts. Am I not making
this obvious? I'm going to sell $400 in parts for $99? Every day! I need
some suggestions on how to make this more apparent. This just amazes me.
I see Dan at ModWright has yet another new linestage. Looks very nice. But
isn't this the fourth iteration in two or three years? Can't tell if that is
good or not. Maybe he is just reacting to customer requests, delivering what
the market wants. It looks that way. I only bring this up because it has the
appearance of upgradeitis, something I want to avoid. Some companies in this
business tend to make very small changes to an old circuit, buff up the chassis
and call it a new model. Same with cars. People always asked me what upgrades
were done to the TRUMPET. Well, none, actually. First one off the line is the
same as the last one, four years apart. The TRUMPET merely lacked features,
not performance. Only evolution so far is the CORNET. From the original
classic, to the improved version with 300 series power tranny, to the new MC
with built-in PICCOLO. The CORNET circuit inside stayed the same, though.
Apr 01
------
So I decided to skim through the audiogon thread on how old you were and what
your job is. Interesting. I kept hearing that this hobby is for old white
guys who are about to retire. Shux, a huge number of responses were from 20
and 30 year olds! Hi-fi is alive and well. It ain't dying or greying at all.
Forget that nonsense. Not many of the posters were over 50. Maybe that has
something to do with computer culture? Also looks like the younger crowd
spends more proportionally on audio. I'd guess the mean to be about 43.
Doing my normal forum browse, huh? AA for sale? That was such a busy place.
Oh well, should have me $50 a month sponsorship. Oh wait! I bet it's a
friggin april fool's joke. Dang, I can't believe I fell for it.
Mar 31
------
Good news, everyone! (futurama) I dug into those unverified charges on my
credit card. Who the heck is micro logic anyway? Well, duh, I finally did a
desktop google for midland, nj. Bingo. Turns out the www.emachineshop.com
place I had the UFO parts made has the same address! So the carges are valid.
Me got confused because the charges went through the other company (same
address). Sorry for any panic I caused.
emachineshop.com
And that reminds me, I sent a pair of these UFOs to RSF for reviews. I wonder
how that is going.
Anyone visit the weekly news at 6moons.com? Turns out some Chinese company has
stolen the design of the transcendent sound grounded grid linestage (a worthy
product, in case you were interested). They copy the machine bolt-for-bolt and
even sell it under the same company name! Beware of counterfeits. Maybe these
are showing up on eBay? I asked Bruce about this, he said he never knew until
some Chinese customers told him. Makes me suspicious.
I know of a Russian company selling "free sota", whatever that is, has been
using my company name, address, and phone number. Must be some sort of a scam.
About once a month I get a call from some very confused Russian dude. I should
record one, they can be quite funny. I made the mistake once of saying "nyet".
On the other hand, I'm very suprised how many of them can switch to broken
english.
Mar 29
------
So it seems there is an abundance of laserjet information out there. Just not
on the HP website. Duh. So in about 15 minutes I tracked down the problem,
same exact symptoms from another user. Problem is the "fuser". Found a
replacement for under $100. Hey, that's a lot cheaper than buying a new
machine! Plus, I already had two brand new toner carts sitting on the shelf.
If I can't get the machine opened up properly, I can buy the service manual
online for another $7. Shoot, ain't the Internet grand?
Got version 2 of ARHIVER almost built up. Forgot that for the 75nF capacitance
in one of the EQ filters requires I build it up from two in parallel. Need to
add a cap and adjust spacing on the board. No big deal.
Mar 27
------
I got this great quote in an email today:
"The reasonable man adapts himself to the world; the unreasonable man persists
in trying to adapt the world to himself. Therefore all progress depends on the
unreasonable man."
Crap, I just discovered that the linear regulator I added to the PICCOLO will
drain the battery at a slow constant rate even when turned off. Shoot, forgot
about the back load. Need to add a diode in there. Found this as I was
getting the noise floor down on the MC. Decided to put the regulator in the
circuit to clean up the residual 120Hz noise on the heater. Distortion on the
MC measured 0.08% at 20dB gain setting.
Made the CORNET MC manual today.
MC Manual
Ok, after a break for lunch I headed back to the lab with new vigor. Tried a
new wiring trick, added a heater cap, and bingo! The hum was gone. Finally.
That makes this baby top-notch quality for versatility and sonic. Unmatched at
under a grand. The MC is now ready for sale.
Mar 26
------
My laser printer keeps spitting out pieces of its innards. Luckily, the defect
is a stripe down one side, which doesn't show up on the manuals. Making a mess
of invoices and everything else. Shoot, and I just bought two expensive toner
cartridges. Hopefully I can find a new HP machine that still uses them. Is it
worth ripping apart this old laser to try and locate the bad part? I think it
is the print wheel, or whatever thingie that puts the ink down. Do they even
sell the parts?
Got new PICCOLOs up and running. No errors in layout. Measuring and sounding
just fine. All I hear out of the thing is hiss. Took me awhile to find the
best wiring for the CORNET MC, as some of the 5kHz would bleed into the heaters
of the tubes. That is solved, but I get a bit of 120Hz hum. Probably a matter
of input/output wiring. Thought I had the ground loops licked, but there is
some residual I need to clean up.
Made some measurements. Distortion at 20dB gain and a 40mV input signal at
1kHz gave me 0.06%. At 12dB this dropped to 0.025%. Overload is very nice.
Distortion drops with input level. Actually, just the 3rd order drops, 2nd
harmonic seems to stay put. These levels are 100x greater than under actual
use. I can't get an accurate measurement when input is just 0.5mV. There was
some 60Hz crap with the measurement technique. Probably because I didn't
unplug the laptop. Bandwidth was from 7Hz to 1.04MHz. Yup, a megahertz.
PICCOLO distortion overdriven 50x
Good to go. PICCOLO boxes on order. Just need to fork over another grand on
production circuit boards. Then I can start shipping kit/2.
Mar 23
------
Wait a minute, I found a battery pack. Ten AA types and it can fit on the back
of ARHIVER. I'll try one out. Only problem is that it's a bit on the ugly
side, so maybe it'll be an option. Wish I could fit it inside, but the space
is already packed with capacitors.
Just pulled the trigger and ordered a hundred PICCOLO boxes. That baby better
sell.
Started a DIY project today. Writing an article on the BUGLE BOX. Found this
funky aluminum chassis at DigiKey that is 6" on a side. A cube. So I am
making boards to fit inside in a stack. PICCOLO on top, then BUGLE, then a
POWER SUPPLY. They are all the same size with same standoff holes. This will
make for a nice project. Build your own phono cube. Probably cost you about
$220 to make.
BUGLE BOX
Got the FRYCORD box up and running. Not happy with the color scheme. All
black and glossy plastic box doesn't look right. It needs a little contrast
with the black connectors. Anyway, this is the basic concept. Easy to DIY.
Might just include this with the FRYGOLD. Or make it an extra.
FRYCORD BOX
Mar 22
------
Had this idea that I can run the ARCHIVER on batteries. That would be cool.
Same concept as PICCOLO. But it runs from 15V and there ain't no more room for
a battery pack.
Dang, now my printer is going south. Shoot, I use it a lot for printing out
manuals and the such. Just what I need, another capital equipment expense.
Meanwhile, selling off the last of the CORNET2 and CLARINET stock on eBay to
pay for my new bike.
Mar 20
------
So I fired up a HAGUSB to plot its distortion. Hey, not bad for a cheap built-
in headphone output. Third harmonic was almost 80dB down.
HAGUSB spectra
Mar 19
------
I signed up for these google alerts, for "hagtech", to see if it found anything
interesting. The other day it pointed to the slimdevices forum where they
started bashing and ripping me for my burn-in FAQ page. Kinda funny, actually.
Except one dude called me "uneducated". Hmmm, that made me realize I neglected
to mention anywhere I have a real degree. So I whipped together this resume of
myself.
Jim H web page
Oh yeah, and here's the burn-in page where I admit to not knowing the science
behind it. Is that such a crime?
Burn-In FAQ
Finally got my EMU0404 hooked up. Install no problem onto XP laptop. Played a
few songs. Was not impressed by the headphone output. But hey, I don't care
how it sounds, only how it measures. Downloaded the WaveSpectra software from
Japan. Got it configured for 24/96, did a quick test of my signal generator.
Exactly what I expected.
1kHz spectra
This software is amazing for the price. Reads in any WAV file or input from
sound card.
WaveSpectra software
Ok, so then I decided to measure the noise floor of this instrumentation. I
downloaded this (also free) signal generator and gave it a try.
SigGen software
Free version won't run at 96k, but it can be set to 24 bits. The following
spectrum was generated by SigGen, output by the EMU, input back into the EMU,
then read in real time by WaveSpectra. Not bad using the stock wall wart.
I'll build a linear 5V supply to se if that helps.
Noise floor
This is a pretty impressive setup, considering it only cost me $200. I'll
run it for awhile to see if it proves useful. If not, I can update to the
real 24-bit Dr. Jordan stuff. But hey, I got at least 100dB for now.
Mar 18
------
Doing my taxes. Yeah, I'm late. But if you haven't run a small business, you
have no idea how much extra work this is. Takes me days to power through all
the data. And I'm not even filling out the forms! I just send all the stuff
to my accountant. Some interesting patterns emerge. For example, I spent five
grand on just postage. That's what I get for the free shipping offer. And the
google adwords, hmmm. Seems the amount just keeps going up. Insidious if you
don't pay attention. They can really nickle and dime you to death. Internet
charges for my websites is like my smallest worry. It is so cheap. Yet I use
it so much. The amount I spend monthly of parts continues to freak me out. It
adds up like you wouldn't believe. I could have bought a Jaguar.
Then I run across a couple of unusual charges from Micro Logic Corp in NJ. Who
the heck are these guys? I find their website. Huh? I check their database
to see if they ever shipped anything to jim@hagtech.com. Nope. Sheet. I got
me fraud charges! I dig up 4 of them totalling almost three grand. Dang. No
wonder I can't seem to ever get this card paid off. Ok, so now I have
initiated a dispute claim. Wonder how long this will take.
Rode the new bike. Very fast. I'm gonna smoke all my old times. Suprisingly
unstable, though. The steering and balance is really different from a road
bike. Any shift in weight, especially on the front, make the thing turn. You
have to be careful, it's very touchy. Also going to take me some time to get
used to the shifters at the tips. What really got me, though, is that when
they said they don't go uphill as fast, they weren't kidding. It's a rocket on
flats and rollers, but a rock going up anything steep. I used to be able to
fly up this hill, now I can barely make it. Mostly it is the gearing. But I
think the out of saddle position and balance is part of it.
Mar 17
------
Oh, I forgot to mention this great article from entrepreneur.com. Yeah, I read
all of these types of magazines. Easy and cheap way to self-generate an MBA.
Seriously, they give out a lot of good advice, digested down without fluff.
Who has the time for school?
The Trust Factor
Mar 16
------
Dang. I did a ton of work on the ARCHIVER pcb yesterday. Was going to finish
it this morning, and poof! The file was bad. Shoot. All that work gone.
Ok, just re-did all of it. Finished the changes to ARHIVER and ordered a new
set of proto boards. These should end up being production units, unless I
discover some more bugs. Hmmm, I wonder if I have enough parts to build this
up. And the backordered male XLR connectors just came in, which is a good
thing, as the pins aren't exactly like the data sheet. Had to change hole size
and add an extra one for the shield. Glad I waited to do this revision.
Layout is a work of art. Very happy with it. Check out this beautiful
symmetry.
ARCHIVER layout
Yea! I just bought me a new racing bike. That was fast. Was really desiring
the Felt S22, but the local shop didn't have any in stock, never mind the right
size. The big mail order place (San Diego) could not sell me the bike because
of dealer restrictions. Then the local shop kept trying to upsell me to a $4k
carbon bike. Jerk. Then kharma hit. A new shop in my neighborhood opened a
few months back, they had a Fuji in the window. Well heck, it even turned out
to be the right size. Friendly, knowledgable, non-pushy dealer. So I did some
research, the reviews were good. Price was cheap, last year's model. And I
could ride it home. I was really worried about a month or two wait to get a
bike shipped in, ruining my training for the season. The best part? It's
called the "aloha". Decent price, in stock, right size, great service, and
aloha. That's what I call kharma.
Mar 14
------
What am I thinking? A RIPPER-like HAGDAC? That's exactly what I told myself I
should not be doing, "me-too" products. Have to stay unique. The lure to feed
off some of their market share by offering a similar product was enticing. The
CHIME is a top-notch machine. It should not be compromised in order to compete
at a lower price point. At $1750 it remains untouchable. The real issue is
marketing.
Ok, jammed all day on this PICCOLO relayout. So many changes. Added regulator
on input, some inductors, more capacitors, better routing and shielding, re-did
grounding on inputs, added output traces to make CORNET MC wiring easier, fixed
hole size problems, added a 4th level of gain and power jumper, re-wired the
gain switch, and added corner holes to match BUGLE. This is one little
flexible board. Mounts on top of BUGLE, in CORNET MC, or in box. Powered by
wall wart, external dc supply (+7V to +15V), internal battery, or 6.3V heater
supply. Jumper added so always-on operation, making the OFF position act as a
0dB active gain for when installed into a MM stage. Many ways to build this
thing up. And it doesn't invert. Got protos ordered.
If only taxes were this easy.
Mar 13
------
Was commenting on the steve hoffman forums about USB playback stuff. There's a
lot of excitment out there regarding the new Benchmark USB DAC-1, which really
seemed to have hit the sweet spot for features and pricing. I bet they sell
10,000 of those things for every CHIME. Makes me jealous. Is the CHIME too
much? Maybe I took it too far in terms of performance and sonics. If I
eliminate the tube stuff I could cut the price in half. Thinking maybe HAGDAC
in a box just like THE RIPPER. I did make a prototype DAC PRO two years ago,
use it to test HAGDACs. Perhaps another black box is just what I need to
cement my market position for USB stuff? It fills a gap in the lineup. Design
time would be very short, as no development is involved. Just rip out the phono
stuff and add HAGDAC connectors. Simple. Only problem is the wad of cash
needed to buy production parts. Hmmm. I will think this one over. Would make
for a nice half-kit. I hate to lose out so much business to the Benchmark.
Mar 12
------
Doh! I just realized the FRYCORD box cannot do current mode on two cord at
once. So no point to make it dual. Shux. Will redesign this concept around
the HM100 plastic box. Then I can sell it as an accessory for $50 no problem.
Hook up the CNC and let it route. Hey, maybe I'll call it the accessory pack.
Can then include some other various adapters. Like 1/4" phone plugs. That
would cover pro and guitar cords too. Yeah, $500 for the FRYGOLD, an extra
$50 or $75 for the ACCESSORY PACK.
Ok, pulled the trigger. Bought a production batch (large) of FRYGOLD circuit
boards and a bunch of panels. That's a quick two grand. Anyway, gotta get
this to market. Will try to have the accessory pack available same time.
Need to update layout of PICCOLO and run another batch of prototypes. When I
find some time, will design box silkscreen and get those ordered too. Oh, got
a quote for that LSK389 replacement part, $7 each in big quantities. Yikes.
So I ordered another big batch from electronix.com. Seems the original Toshiba
parts are no longer in production. Been able to get them for $2 each. If
still available, I'll get a couple thousand. That should cover me for awhile.
Ok, got an RFQ out to Hammond for PICCOLO boxes. Stock color is black, I can
add white silkscreen. As these are long lead items, I'll probably just go for
it. Made a label of the silkscreen, stuck in on a blank chassis, drilled it
out. Fits PCB perfectly.
So many balls in the air at one time, having a hard time keeping things on
schedule lately. Just trying to get from point A to point B. From where I am,
to the new HAGLABS. Just shoring up HAGTECH and financing before I can commit
the time to design the RGP. Need to set myself up for continous revenue to get
through a majorly long development cycle. Right now I am hung on the PICCOLO
and ARCHIVER relayouts. Get those done and I think most everything will be
back in play. FRYGOLD is first out of the chute, with production parts already
on order. I'll quickly add the accessories pack (FRYCORD & stuff) as an
option. Shipping product in early April. In parallel the PICCOLO should hit
production in late April. CORNET MC same time. Looks like ARCHIVER will be
ready for May. That's a lot of product launch! Lots of inventory costs. Lots
of manuals to write. Anyway, that should supposedly free me up to do RGP in
June, however, I'd be happy enough to get all this done by July vacation.
Meanwhile, I realize I have about $4k in product out for reviews. Imagine how
many more I have to send out now. I think ARCHIVER and PICCOLO at least.
Music Direct already wants to pick up the FRYGOLD, so I bet they also want the
PICCOLO. That should be enough stuff in the catalog retail market to get the
HAGERMAN name noticed.
The wild card here is the COMPRESSOR. Maybe I will take a break and complete
it. Then I can decide on possible product. Another side item is the
FRYSPEAKER, a new waveform optimized for cone break-in. It can be a track
included on my CD. Finally, I haven't been able to locate a low cost logo
badge manufacturer. Wanted laser engraved metal or something. Most are $3 or
$4 a pop in quantity. I need something under $0.50. Ok, that's it. Jam my
ass off until summer.
Mar 11
------
Looking into software to run as a spectrum analyzer. The recommended Dr.
Jordan stuff looks really good, but by the time you buy all the options and get
the 24 bit stuff, it comes out to $650! Dang. The SpectraPlus is $250, but it
doesn't look so good. I guess I might try out a free italian one first. Was
hoping to speed up some of my testing, like distortion. The spectrums can be
useful. I seem to be hooked on my analog gear. Not sure I get any useful
jitter tesing out of this suite. Mostly, I think the resulting graphs will be
impressive for marketing purposes. Maybe I'm just a geek.
Drat, my bike broke. The frame cracked on a rear arm right at the crank house
weld. Shoot, I had just gotten back into form and was on schedule for the
racing season (ok, only 3 this year). What a setback! On the other hand, you
can always turn disaster into opportunity. First off, I realized what a stroke
of luck this was. Had I not seen the hidden crack while riding I might have
just kept going. Eventually the torsion on the other arm would have cracked it
and snapped off the rear wheel, likely shattering the rear carbon stays and
dropping the crank right into the pavement. At 20 plus mph this would have put
quite a jolt into my feet throwing over the front of what was left of the bike.
That would have been messy. Imagine what I would have given to go back in time
and notice the crack. Well shux, I must have done something right. I knew
something was off, as last week the gearing went out of alignment, so did the
rear brake. And that funky noise. Scary to think I rode the crack for at
least a week. And yesterday I was doing hills.
Anyway, turning this into an opportunity, I think it is time to order me a new
bike. Kharma in action? I can finally get that S22. Dr. Jordan will have to
wait.
Mar 10
------
Page 94 of Mix magazine, review on the sta-level compressor, $2,350. I keep
thinking, if they can sell this, my COMPRESSOR should be a success. Way more
features and probably better sound (I bring a nice high-end touch to the pro
world). I hate to give this project up, even though I need to focus. Still,
can probably sell factory-direct for $3500 or so. That would be fine in this
boutique market. The key, would be getting a potent review, just like this
one. Otherwise, forget it. If I can only catch up on all the other projects.
Finished the FRYCORD project. Maybe this will just be DIY. I'll write up an
article next week. Easy to build.
FRYCORD attachment
Then drill out the PICCOLO box. Fit is ok. Noise went down. Sound is just
fine. Need better knobs.
PICCOLO inside
Noise was hard to measure, way down at the bottom end of my instrumentation
capability. I was on the 0.3mV full scale setting. Too near the noise floor
I got 61dB SNR referenced to 5mV output with 47k input. It was all hiss. At
47 ohm input it was only 6dB better, but limited by instruments. So hooked up
my A-noise active filter. Then I got 65dBA at 47k and 85dB at 47 ohm input.
Keep in mind, this is referenced to a 5mV output. That's the equivalent to
0.28uV input noise. If I played marketing games and referenced the noise to
a 1V output (which this amplifier will do no problem), then SNR is 46dB better,
or 131dBA. Needless to say, this headamp is quiet enough for phono. Oh,
testing was done at 26dB gain.
I wonder how much is contributed by just the input resistor. Unweighted, we
get 3.9uV audio band noise for a 47k resistor. The 47 gives off 0.12uV. That
is a 30dB difference. The amplifier measured about a 20dB difference, so the
intrinsic noise of the amplifier itself is about 3x the noise generated by a
47 ohm resistor.
Mar 09
------
Just whipped up a new TONE audio ad. Ok, enough branding already. Time to
actually mention a few new products. Hopefully this will get some more
attention. Was going to also put in the ARCHIVER, but thought this simpler
version was more effective. Sort of looks like two ads, not one.
TONE ad #3
Also came up with the idea to put a low dropout 6V regulator in the PICCOLO.
Testing today showed the circuit works fine from 5V to 10V. But above 10V you
can smoke it. So my thought is to add the regulator. Even if it drops out of
regulation, it still works down to 5V just fine. Above 6.2V and it regulates,
providing even more noise rejection from the outside world. The other reason
was that if anyone wired this up to a BUGLE with +/-15V supplies, you would not
have to add an extra level of regulation. The PICCOLO can now handle a very
wide range of inputs. Getting the metal bozes today. Will carve up this
weekend. Then I can have a photo and do some real testing on noise, etc.
Mar 06
------
Building a new FRYCORD attachement for the FRYBABY and FRYGOLD machines that is
specifically for power cords. Bought some parts from the hardware store, CNC
cut out a blank top panel. Add some RCAs and NEMA ac input plugs. Viola! Can
be another DIY plan. Or maybe I'll sell these for $75. Save you the time and
agony of construction.
Shipped off all the AudiogoN machines. But get this, the site people emailed
me and said I have to upgrade to a special new 'mercantile' account since I'm a
manufacturer. I can get this luxury for a mere $3k per year. Such a deal. Ok,
maybe it is for someone who uses them as a storefront. Shoot, all I do is sell
off one-of-a-kind prototypes or my own personal stuff. Rarely do I offer
regular production. So that's maybe 10 listings per year which pulls in $2k to
$3k. Heavily discounted, I might add, so there is no profit. And to keep
doing that they want $3k in return. Heck, I would lose money upgrading my
account. Better to just dump these machines into a landfill. Or maybe find a
new place to sell off these odd pieces. Any suggestions?
Mar 02
------
Spent the whole day re-coding my website. Added new products. Revamped the
entire thing (but same look). Re-did order form. This takes up a sheetload of
time.
Mar 01
------
Feeling like I am falling way behind. Got orders out. But so much else to do.
And then I realize I need to make yet another product. Power cord burn-in has
been an issue. I never included the male side connector (which shorts L and N
together) in a product for fear some idiot would plug it into a wall. But doh!
All I need to do is add a fuse. I just use a NEMA receptacle with a fuse to
make the short. So a new product will be an attachement to any of the existing
FRYKLEANERs that has power cord connectors on it. I don't know what to call it
yet, but will just be a small passive box with connectors. RCA inputs connect
right to your FRYBABY or FRYGOLD. Have to do this as many folks are looking
for such a solution.
Meanwhile, got the whine and hum our of the CORNET MC. One trick was to add a
small inductor to the 6V input. I will also make some other routing changes to
the PCB and add another shield or two. Also need to add a default 1x gain
setting for when the unit is off. Add a jumper so the MC version won't go off,
but instead give 0dB gain so it can also run MM carts. The external PICCOLO
box will not have the extra jumper installed.
Feb 28
------
Ok, finally. Got to listen to some stuff. Finished a CORNET MC. Sounds
friggin great, but some of the 5kHz whine comes through. A little bit of buzz,
too. I need to work on the wiring. Sonically, the PICCOLO is extremely
transparent. Adds nothing to the CORNET sound.
Also fired up the ARCHIVER into the CYMBAL GOLD headphone amp. Yup, that
works too. Maybe a little too much gain. I am getting some of that buzz
through the TT cables. When removed the stage is incredibly quiet. No whine.
Good, I am done with the CYMBAL then. ARCHIVER is ready for relayout.
Ordered me a Dynavector 20XL today. Stu thinks he has one in stock, needs to
fetch. All of his stuff is in storage on north shore. Meanwhile, the EMU-0404
should be here any day. I want to hook it up with that SpectraPlus analyzer
software. Keep you posted. Hopefully I can get some decent jitter and
distortion measurements out of it.
Took a photo of Mrs. H. for a passport. She looks nice, could pass for 32.
This is completely unretouched.
Mrs. HAGTECH
Feb 27
------
Spent the day building FRYBABYs. Didn't get anything else done.
Feb 26
------
Got the PICCOLO prototype up and running. So far so good. Only a few minor
mistakes. A silkscreen reversal on some resistors, and goofed up traces for
the gain settings (rotation going wrong way). Fortunately, I can still build
it to operate normally (no jumpers or cuts) with 2 gain settings. Then two
mechanical issues. The battery holder leaves no room for mounting screw heads,
and the holes for the dc power jack were too small. Measurements look good.
Great waveforms, no measurable noise (40uV broadband at output 26dB gain).
Can't find any trace of the 5kHz switching noise. The real test is hooking it
up and listening. Only I just realized I never got that Dyna 20XL. Shoot,
more stuff to buy. Also need to listen to ARCHIVER as it now has proper output
connectors. Can listen to CYMBAL GOLD. I also have the first FRYKLEANER GOLD
done. Hard to find time, as I still have plenty orders to fill (and they get
priority). Anyway, the PICCOLO looks a little like this:
PICCOLO
Built a second one for mounting into the CORNET MC. Discovered the old heat
sinks were too tall. Luckily I still have some original ones on hand that are
much shorter (very little heat here). Boards fit very nicely together. Shafts
are supposed to stick out bottom of chassis. Now I have to design a reasonable
wire routing. My evil plan is working.
CORNET MC
Feb 25
------
There it is, page 6 of latest TAS. An ad for an expensive fancy turntable with
three arms. Beautiful. That's my customer. Or will be. Everyone who buys a
table like that is looking for a phonostage to match. That's the market for
the RGP. These are the buyer's who will say "it's gotta have a HAGERMAN badge
on it".
Feb 24
------
Just realized I spend way too much time commuting. Yeah, you do to. But get
this. My morning commute is 1.5 hours and I work at home. Well, garage. This
past week traffic has been bad and can take 2.0 hours! That's to drive kids to
school, get coffee, return. Lately, I have to go back into town for other
reasons later in the day. Like kid's volleyball. So that's one, two, or three
trips into town each day. 1 hour round trip no traffic. Thursday I swear I
was behind the wheel for 4.5 hours. How am I supposed to get this ARCHIVER to
market when so much time is wasted? I need a better plan.
Parts just came in. I can now finish the FRYGOLD, ARCHIVER, and PICCOLO proto
build. Except I ordered the wrong box for the latter. Should be a busy
weekend.
Feb 23
------
Yep, this is it. Best sound yet. The www.usb-audio.com driver for xp is the
best yet. This is the way it should have been done in the first place. I am
now using latest foobar2000 with this usb_asio driver from Germany. No
wierdness, no games, just straight unmodified 16 bit data sent out USB port.
Listening here with a CHIME connected to an OBOE (for headphone output). Best
playback yet from CD. Very clean and open. Of course, songs like Shakira's
Hips Don't Lie sounds like crap no matter what. A fine tune, but perhaps the
most non-audiophile recording I've come across. Either that or Where'd You Go?
by Fort Minor. Nothing I can do makes them sound even remotely ok. However,
other modern tracks are startling. Take Because of You by Kelly Clarkson.
Whoah, if you listen closely, the echo and reverb becomes a completely coherent
vocal track of it's own. It's like you can hear another singer who's standing
way off in the audience about 60dB down. Reminds me of groove bleedthrough on
some LPs. You know, where you can hear ahead. Another example is the Disney /
Collins track of You'll be in my Heart. It is now apparent that those are real
cellos used in the recording studio. I wasn't sure before.
So I am trying to strike a deal with the driver folks. Maybe I can get you
guys a discount rate. I paid EU49. Steep, but for me worth the result.
Ok, I'm gonna make some room in my product lineup. Might possibly discontinue
the TRUMPET. Not sure about that one yet. The big change is to no longer
offer the CONSTRUCTOR series as assembled units. This move is to free up space
and inventory for newer projects. They will become DIY only. So I'm going to
auction off cheap my stock of assembled CORNET2, CLARINET, and CHIMEs. I have
3 each of the first two, including my own personal units. I will even sell a
CONDITIONER in black chassis to match. No CYMBALs. Also going is a BUGLE PRO
and a wood TRUMPET (XLR). Look for the auctions on AudiogoN. Coming soon.
Went out an bought me an EMU-0404 unit. Will use this as test equipment for
S/PDIF send/receive testing, and as a spectrum analyzer with SpectraPlus.
Curious to see what types of components are used in it. Might have to spiff it
up a little with better opamps, trannys, caps, and clock.
Feb 22
------
For anyone looking to buy a full BUGLE kit, with all parts included, check out
this seller on eBay. It's ok, I sold him the boards. This is all above board
and authorized by HAGTECH.
eBay BUGLE kit
HAGTECH business consultant WB suggested a fine idea - to make a HAGTECH logo
badge that can dress up the DIY kits. Like a laser engraved metal plate.
Something kinda fancy. It's like free marketing. Just make it look real nice
so that people actually use it. Ok. Now why didn't I think of that. In fact,
I think Bottlehead does this. Don't they? I will look into this. What I
really should do is send out one for all previous kits sold. So if a customer
once bought a CORNET and a FRYKLEANER, I'll send them two badges. This concept
makes a lot of sense. Way better than the logo pens I bought for VSAC03.
Tried out the www.usb-audio.com driver for windows. It's the alternative to
ASIO4ALL, which takes a bit of work to get installed. And then, after I loaded
audacity, the thing never worked right again. So I had been using directsound.
Anyway, uninstalled all of that from my laptop, put in new foobar2000. Then
loaded the driver from usb-audio.com. Wow, best sound I've had yet. Seems to
be the real thing. No goofy wrappers and dlls and other wierd stuff. Just a
new usbaudio.sys for wondows, select it in foobar. So good I bought it. Yeah,
like $60+ just for a chunk of code. But for me, it's worth it. Now it is
gauranteed to bypass kmixer and all that other crap. I play WMP files through
the laptop speakers, foobar through a HAGUSB, and audacity through a RIPPER.
Works just right. So far. Will keep you posted.
Feb 21
------
So I read on some forum that a HAGUSB owner has successfully used the usb_asio
software. Ok, I downloaded it. Will try this out. Has to be purchased. Ok
for me. Probably you too, because I think it might be a much easier and more
robust method to obtain bit perfect output. Keep you posted.
Ok, replaced original tranny in CYMBAL GOLD. Now both channels match
perfectly. I suppose the lower power on the output tubes can't hurt. Will do
some lab measurements to see if dual-mono screws up anything.
Dang, only have one good male XLR adapter. Can test only one channel at a
time. Running a 20 ohm pad for the headphone output (otherwise way too loud),
so there is some loss of output power. When tested with a 8 ohm load, I could
get 6.6Vrms at the slightest onset of clipping, which is real soft. So that's
7.5W output, but because of the headphone loading, only 5.4W reaches the
binding posts. Maybe I need to change this. Anyway, the machine was very
quiet, with about 80dB SNR ref 1W output unweighted. Bandwidth was 9Hz to
90kHz. Pretty amazing considering its a Hammond tranny. Buttoned up, the top
of box got hot, but easy to touch. You can keep your hands on it no problem.
After 1 hour, I checked the temperatures inside, everything was pretty cool
Actually cooler than a normal CYMBAL. I may have to rethink that headphone
output. Wired straight, it likely works well for Sennheisers, but need a 20dB
pad for the Grados. Fired up one channel on the HORNS and played some phono
through an OBOE. Startling the vocals. But I really need both channels to
make a real judgement call. As soon as my XLR connectors come in, I can finish
the ARCHIVER, and then have balanced cables to CYMBAL GOLD. That's the real
test.
Just changed to a 20dB headphone pad. It works. 2 ohm output impedance. I
guess I'll leave it that way for awhile.
CYMBAL GOLD innards
Feb 20
------
I'm still waiting on them dang make XLR jacks. Been holding up the FRYGOLD
project now for over a month! Darn it, I need to get that thing into
production. Also holding up ARCHIVER. I want to install a pair on my working
prototype just to make sure I have proper mechanical fit before I update the
layout. That project too, is virtually ready for production. Just need to
layout and build the pre-production unit to prove out final specs and to take
photos.
Meanwhile, spending a lot of time trying to finish up this CYMBAL GOLD machine.
Wired it up over the weekend and got it running. One channel was out - turned
out the power tranny developed a problem. Not sure why, but with just the
primary connected it pulled too much current. Not enough to make a fuse blow,
though. Anyway, with a lot of work I replaced it. But now, that channel has
a much lower B+ than before. Original tranny put out 208V B+ and the new one
190V. Heater voltages are same between channels. Swap rectifiers, same thing.
It must actually be a change in the winding ratio. Dang, now I have to swap
out the other tranny to get things matched up. Or maybe I can fix the old
tranny. I'd much prefer 208V B+ instead. This project taking up way too much
time and money. Especially since it is a non-revenue generator. Just a one
time machine for myself.
Also need to order some more parts - to build up the first PICCOLO next week.
Will also build up a CORNET MC (PICCOLO inside). I might try a 12BH7 as the
output tube instead of the 12AU7. Reports from customers is that this works
pretty well. It's also a nice change and offers something different in the
marketplace.
Thought a little about long-term goals. My present strategy looks pretty good,
at least for the next 2 years. I keep fine tuning it. But what about bigger
goals? The answer came to me from TONE audio magazine, a comment by Jeff
Dorgay. He wrote "... but if I'm in the position to write a $50k check, it's
going to be something with a Porsche badge on it." That's it! To get
audiophiles thinking "if I'm going to spend $15k on a preamp, it won't be a
Krell or Levinson, it's gonna have a HAGERMAN badge on it." Bingo! The long
term strategy is to become the world's *top* audio designer. Whether or not
that is achievable is unimportant. What counts is the attempt. It is the
things set in motion to accomplish such a goal that matters. Boil it down to
the simplest terms, this strategy is one for success. Shux, who needs an MBA?
Feb 15
------
Finished placement of PICCOLO layout. Wired up, starting to run traces. Had
a hard time with decoupling caps (no room) and the proximity between the power
supply section and the output connectors. Found me some nice, cheap terminals
that can work as grounded shields. Just need to be wary of ground plane
currents. Fortunately, the 5kHz switching of the supply is a LOT easier to
deal with than 120Hz switching. Take your choice. The simple 100 ohm / 100uF
RC filter sections provide better than 40dB rejection. Two of them in series
gives 80dB. I have three, so by the time the noise gets to the gain stage,
it has to be maybe 120dB down. That's the theory, anyway. It worked in the
ARCHIVER no problem. I'm really liking this design. Going to be a super easy
build. No wires. Build and test before you stick it in a box. Lots of self
shielding. Battery pack mounts on back. Fits into CORNET perfectly. Just a
few more of the difficult traces to run. Probably get these ordered later
today.
PICCOLO layout
Oh yeah, my wife had a great idea yesterday. Build a segway-like thingie for
golf clubs. A self-propelled pull cart! I don't think it would be too hard at
all. Nor that expensive. Unless it is intended for riders, then you gotta put
some money into it. But to carry clubs, you could sell it for $1k or so. What
a market sweet spot! It sits there balancing itself. The coolness feature
alone would make it sell. Tilt it and by trying to balance, it propels itself
along. Either direction. Not sure how to handle turning. Could make a great
half-kit!
Feb 14
------
So my wife wanted to do something different for Valentine's, rather than the
usual dinner out. So we went golfing. Tough little par-3 course nearby. I
don't know of anyone who can shoot par there except perhaps my nephew (one of
those prodigys, yeah, he's even beaten Tadd Fujikawa a few times). Hadn't
played in over a year, so it was a real treat. Rust all over my clubs.
Literally. But played really well, plenty of fine shots (horrible putting).
Shot maybe 80 (par 54). Nice sunny day. Can see whale's swimming in ocean
nearby. What more can you ask for?
Feb 13
------
Waddayaknow. The cutting of acrylic is easy. Just had to make a cut with a
razor along a straightedge and then with uniform pressure snap it off. Took me
a few tries to get the process down. Might need to make me a special hinged
rig to speed things up. Anyway, the good news is that I found a way to make
low cost clear acrylic back panels for the FRYGOLD. The result looks nice.
Just finished the schematic for PICCOLO. Seems each design I do does something
different. This one pulls a couple of extra power supply related tricks. No
big deal, but it is looking very nice indeed. Circuit is there. Now the only
question is if I can get the layout quiet enough. Issue is keeping the 5kHz
switching noise out of audio signal. I was successful on the ARCHIVER, but
that board had a lot more space to utilize. I'm hoping that careful ground
routing and electrolytic capacitors doubling as electric field shields will do
the job. Layout in progress. Think I can do this for about $85 in parts. Or
a factory-direct price of $250. If I go retail (likely) it could be $350 msrp.
That's for a very decent active headamp with customer friendly features. It
has a nice metal box, can run from either 4 AA internal batteries or a wall
wart, and has variable loading and gain (independent!). And built from
discrete matched JFETs, not an opamp. No feedback.
Ok, that's not quite as cheap as I had hoped for, but still represents a killer
value. Can't find too many alternatives on the market. So far the Graham Slee
Elevator, ZYX CPP-1, Klyne SK-2, and Dynavector PHA-100. All appear to cost
over $1000 and do not have the features or performance of the PICCOLO. Could
be another example of me being way underpriced.
Have this idea for FRYGOLD packaging. Use a cylindrical cardboard tube as a
box. Should provide great crush protection. And the FRYGOLD fits perfectly
into a 2.5" id tube. Make it 20" long and the wall-wart fits in one end.
Everything very tight with product manual wrapped around the chassis. Kinda
innovative for audio. Just put address label on it and ship.
Feb 12
------
Had this crazy idea last night. Got into bed and watched a little TV. That
motorcycle show American Chopper was on. I like it, Pauli Sr. and Jr. custom
building rad bikes. Well how about doing the same for amplifiers? Ok, not the
same sort of market draw (unless it was custom guitar amp for big name music
industry star), but still I think you could make a pretty interesting show (at
least one episode) that showed the construction of a totally custom and tricked
out audio amplifier. I couldn't stop thinking about what would be possible.
Make a 45 SET amp like a CLARION, but with extra chassis pieces to get bulges
and odd sculpted formations and cutouts added. Put on some acrylic, wood, and
other trim. That's why I think the 45 would be a good tube. Very retro, and
way cool looking. Now if you could only hand-wind the iron. Anyway, the idea
is to make a show using the same conceptual approach. Show the initial thought
on design, various layout possibilities, and then the hand construction of each
piece. Put it all on some schedule that it *has* to be done by RMAF for some
special customer. I like the idea. I could pull it off. The question is to
what end? Will this serve as a nice piece of advertising. I'm sure it could
gets lots of audiophile play on youtube. Do I have the time and money for
this? Do I really want to switch modes and become a custom amp builder?
Bought a large piece of plexiglass. Or is it called acrylic? How does one cut
this stuff? Can I just score it with a razor blade and then snap it apart?
The guys from MD suggested a piece of clear acrylic added to th back of a
FRYGOLD would give it a more finished appearance. Yeah, it's a good idea. But
I haven't worked with the stuff before. Bought the material to use as a
reflective mirror base for photography of new machines. I plan to make a "gold
rush" ad for tone audio magazine featuring the CHIMEGOLD, FRYGOLD, and
ARCHIVER. Maybe I can chop off a little piece as an experiment. Sadly, still
waiting for the make XLR connectors to arrive from backorder. Holding up two
of the new products.
A guy from Croatia just asked me if the FRYBABY works on speakers. I gave my
usual answer, no. Maybe I'm wrong, but when I tried it on my HORNs it just
wasn't getting anywhere. Only when I switched to drum music (and loud at that)
was there rapid progress. Anyway, it gave me the idea of a break-in signal for
speaker cones. The FRYKLEANER waveform works fine on wiring, including voice
coils. The problem is the cone. It don't work on cones. In my opinion,
anyway. So here's the thought: Make a new CD track that does work on cones!
Yes, another background project. From my limited experience, I'm guessing an
impulse waveform will work best.
Ok, yesterday's category? It was LISTENING. That encompasses two things, the
research involved in tuning and tweaking an amplifier, and paying attention to
customer and industry feedback. You can get a lot of good advice for free.
This is not a novel concept, business gurus have talked for centuries. I just
think it's time to identify it's importance by giving it a new category. A
company should actually have a separate department dedicated to this process.
Slim Devices takes it a step further, allowing the customer to not only give
feedback and defining new products, but by also having them do the design and
engineering work. For free!
Feb 11
------
So I've put together the HAGERMAN team. Below is a list of each displine or
"hat" that must be worn. This is the team of folks that are putting together
our products. As the team grows, initials will be added. Note there is one
discipline listed you won't see mentioned anywhere else. Mostly.
Management - JH - business strategy, vision, goals, specifications
Financing - JH - accounting, investments, cash flow, credit, taxes
Marketing - JH - advertising, sales, shows, articles
Customer Service - JH - technical support, web forum, emails, blog
Engineering - JH - analog, digital, mechanical, & pcb design, software
Listening - JH - prototype development, tweaks, research, feedback
Technology - JH - website, network, computing
Manufacturing - JH - assembly, test, warranty repair
Purchasing - JH - procurement, inventory
Shipping - JH - delivery
Just as important is my list of informal advisors. Experts in various areas
that can be tapped for advice and counseling (JH's are not me). These folks
have been invaluable for helping me to steer through the wilderness. Anytime
I need to know anything about anything the answer is just an email or phone
call away.
JH - style, fashion
SO - dealers, listening, industry
TM - turntables, carts, music
WB - business
WB - photography, marketing
JH - digital
JR - retailing
RB - audio guru, customer feedback
CR - tubes, europe
DW - audio business
ES - speakers
JD - advertising, photography, graphics
WS - retail
Seems I spend a lot of time in the customer service category. To me, it is
very much wrapped up with marketing. How one treats a customer is critical
to reputation and future sales. Word of mouth is huge in this industry. For
a while there I was beginning to slump a little. My answers to questions were
getting shorter and less helpful. Sometimes I just wanted to answer "that's
the beauty of DIY, you can try anything you want", which is both curt and does
not really help the customer. Chaulk it up to a bout of laziness. I actually
pissed off some customers. Whoops. Sorry about that. My bad. It has been
recognized and I am back on track trying to deliver more informative answers.
So yeah, this hat takes up a LOT of time.
Interestingly, the engineering hat often gets the least priority. Most other
jobs have to get done first. Orders are filled promptly. That means parts are
ordered, machines built, tested, delivered, and the accounting that goes along
with that. Bills get paid and customer questions answered. Only when there is
time leftover do I get any engineering done. Fortunately, that's a few hours
every day. I admit, that's what I enjoy the most. My least favorite is sales.
But hey, you have to make sure the team gets everything done. Any missing link
in the chain and the business falls apart.
Feb 10
------
Playing some more with PICCOLO layout. Moving things around to fit. Noticed
that in the 3x4 box that the power supply junk was too close to the outputs and
amplifiers themselves. Had to change to a longer 3x5 box. Now I can move the
dc input jack away, use a wall of tall capacitors as an electric shield between
switching supply and amplifier. Also, since the box is now deeper, I can add
an optional 4AA battery pack to the bottomside. The dc jack has a built-in
switch, so selection is automatic. Gives you the option of wall-wart or
battery mode operation. The problem was no power switch. Constant drain. One
solution was to add a wooden peg that could be inserted into the dc jack to
turn it off. Clever, but just too inconvenient. Aha, reduce the number of
gain settings and I can use a 3-throw switch! One for power, the other two for
channel gain. Heck, who needs 6dB gain anyway? So now the box has a power
switch, gains of 12, 20, and 26. Or maybe I can label it 4x, 10x, 20x? Six
settings for resistive loading. LED is now between output jacks.
PICCOLO panel
The configuration is working out well. A preliminary layout shows plenty of
room for components and traces. Hopefully that is enough distance between
supply and output. Board is completely built in one piece, no wires. It fits
onto panel and it held in place by the rotary switch nuts. A standoff for the
GND connects PCB to chassis. I can just use a knurl nut like the TRUMPET.
RCAs are actually not touching chassis, somewhat lowered into the panel. They
stick out a little. Have to make holes in panel large enough to fit the huge
cables folks make nowadays (like the eichmans). I think a large rubber washer
surround will hide the guts. Will do same for dc jack. This construction
greatly simplifies assembly and cost. I also lined up extra mounting holes for
standoffs to CORNET boards. Component height and spacing is just right to fit
between electrolytics on both CORNET and C2 boards.
PICCOLO layout
For a box, I'm thinking my best option is to bite the bullet and have a whole
bunch pre-fabbed by Hammond. The raw aluminum is tacky, even with a nice
decal. No, the assembled machine has to look nicer. So maybe painted black
with a white silkscreen. I should be able to get 100 of them for maybe $2k.
If the prototypes work out sonically and I can keep all these great features,
looks like it can be a very good seller. I need to do some research here, but
it sure doesn't look like there's a whole lotta competition out there. Maybe
MD will want to pick this up too. Getting closer to $300 retail.
And now I'm thinking, if I'm gonna really spend two grand, maybe I should just
get an S22. That's what I really want.
S22
Feb 09
------
Went to a piano recital tonight. First note. Holy shit!!! What a sound. It
was a kid maybe 6 years old, but she was playing the bottom octave. The sound
of this machine was unbelievable. My wife picked up my jaw from the floor.
Even she commented on the grand sound. Ok, the playing and technique was what
you'd expect from a bunch of kids. But it didn't matter. I just couldn't
believe the amount of air this thing could pump out. Yeah, it's been awhile
since I've gotten this close. Well damped room. I was maybe 13 feet away. My
piano at home cost me plenty, but it sounds nothing like this. It was like the
bass strings were 50 feet long. The entire thing sang as one. I gotta keep
coming back to calibrate my ear. Yeah, it was a Steinway.
Great progress this week. Determination and the willingness to try a whole
bunch of stuff saved the ARCHIVER from the scrap heap. It also lead to a
successful demonstration of the PICCOLO circuit. And now that design is well
on its way. I also had three or four reveiwers contact me for various
machines. Sales slowing down a little, but that's because everyone is
spending on Valentines. Still waiting for male XLR connectors. Holding up
delivery of the FRYGOLD.
Can't wait to get to the RGP. This mad rush to clean up the houshold is taking
longer than I thought. Actually, it is quite a few products introduced in not
too many months. FRYGOLD, ARCHIVER, PICCOLO. Also the CORNET MC.
Feb 08
------
Built me a proto of the PICCOLO circuit onto a spare ARCHIVER board. This is a
little different from the headamp section of the ARCHIVER in that it uses
current sinks in the tail instead of resistors. This allows me to run a much
lower voltage on the negative rail, simplifying the power supply design. So I
can now get away with a single ICL7662 to create both 2V and -1V rails. After
much filtering I think I'll be left with about +8V and -4V to work with. That
is more than enough, especially for such small signal amplitudes. Well, the
proto ended up giving me excellent results, but only after I increased the
drain resistors to 5k. Same as ARCHIVER. Anything else limits maximum gain.
Here I can squeak out 25dB. Close enough to call it 26dB. Then I can have 5
useful settings: 0, 6, 12, 20, and 26. I was worried about the high value
resistor's contribution to noise. But then it calculates out to only 1.3uV.
Fed into a 44dB MM stage that gives 0.2mV broadband output noise. Or about the
same as a BUGLE (which is more than enough quiet). Then I realized that the EQ
is helping out a lot here, as the 20kHz signal gets dropped by 20dB, so this
johnson noise value goes down quite a bit more. Hence, don't worry so much
about the 5k resistor. Even the ARCHIVER sounds and measures way more quiet
than is necessary.
The other good thing is that the lab measurements are jiving almost perfectly
with the SPICE simulations. My JFET model is really close to reality (see
below). That saves me some time as I can do a gain plot without unsoldering
anything. With present values and the FETs operating at 0.8mA, the gain is
thus:
PICCOLO gain
I did some distortion runs in SPICE. The FFT is a nice thing to have. At an
input signal level of 100mV, distortion was mainly 3rd order at about -47dB.
Dropping to 1mV input with 22dB gain (more life-like), distortion fell to below
-110dB and mainly 2nd order. I don't know how real that is, but the circuit
has proven extremely linear, and there's nothing like small signals to make it
even better.
Looking at boxes, I did a quick design of one possible implementation. This
is a cover plate for one of those low-cost aluminum cast enclosures. I think
I'll have to use a regular decal, as a finished deluxe faceplate from
frontpanelexpress.com would run $50. Such would make the cost too high. My
guess is that with a decal, I can sell this for $200 assembled.
PICCOLO panel
Also added a resistor noise calculator to my design theory web page.
Resistor noise calculator
Feb 07
------
Oh yeah. Did a lot more playing with relative gains, etc. in the ARCHIVER. It
was a little short on overall gain. And I wanted even more extra headroom. I
ended up changing FET biasing and loading too - in the wrong direction - if all
you care about is SNR. Resistance values went up, theoretically spoiling the
wonderful SNR. Well shoot. It's still quiet as a mouse. Quieter than any of
my other stages. About 80dB unweighted, broadband.
Not only that, but whatever I did before to measure the gain of the front-end
was wrong. Maybe I had an issue with generator loading. New calibrated
measurements show my FET stages are now getting almost exactly the gain as my
SPICE simulations. In fact, 1dB to 2dB more, depending on settings. Was able
to accommodate the nonlinear adjustment and calculate a new set of resistors
such that the sensitivity works nicely in 6dB steps. Anyway, the gain controls
are now calibrated in proper size steps. More gain, better headroom. Also
biased the output stage to higher current for better drive. The result is yet
another step ahead in sonics. Extremely open and clean. No fatigue at all.
So I recorded me a song. I invite anyone here to download it and compare to
the CD. Let me know what you think. Use a rega P3 with a goldring MM cart.
Maybe I should do the same thing with a RIPPER.
Norah song (33MB wav)
Here's a scan of the schematic with various lab notes scribbled on it. This is
how documentation looks during the prototyping and tweaking process.
ARCHIVER schematic
Feb 06
------
Tried out my concept of moving the 'cut' stage earlier in the ARHIVER. Working
way better. And now I am getting a lot more gain, very close to what I had
originally expected. In fact, the last gain stage (trim for adc) puts out a
whopping 28dB at 100 ohm setting. That's differential, so if I remove one
input, it drops 6dB to 22dB. That's very close to the simulator's 20dB. And
it is not the same as I get with the input stage. So something is wrong there.
Maybe I have a layout error. Anyway, headroom went up at least 10dB. Perhaps
more. Starting to look pretty good. When I get a chance, will modify other
channel to match and do some more listening.
Ok, now we've got a HAGERMAN. The ARCHIVER is a whole new machine, with the
shifted EQ and gain structure. Everything falling into place. Very quiet box,
with a relaxed presentation. No loss of detail or transients. Odd, but it
seems the bass is better than compared to a RIPPER (my SS reference). The
RIPPER is a very staightforward and solid SS stage. Very accurate. The
ARCHIVER (not done yet) was smoother and more relaxed. I could turn it up
louder. Seemed a tad warmer. Still, not quite the same as a tube stage, but
more easygoing than I had expected. Right now I have to place it between a
RIPPER and a CORNET, sonically. I'm going to play with it some more, work on
more headroom and better front end gain. Sadly, these changes will require a
major relayout. But it ain't done until it's done.
Did some experimenting with HAGUSB. Still trying to figure out exactly how the
internals to that PCM2704 work. Very complex. By adding a HAGCLOCK, I could
tweak the 12M clock on the fly, listen and watch what happened to the output.
Also hooked it into a HAGDAC, which then gave me a perfect readout of audio
clock frequency. No matter what I did, ultimate clock rate was determined by
the PC. All depends on the 1ms USB packet rate. However, as I changed the 12M
clock, the audio clock would go with it for a moment (phase transient) and then
drop back to nominal. Adjust too fast and HAGDAC would drop out of lock. So
the 12M xtal on the HAGUSB does affect output frequency, but only indirectly.
And only when it changes. What does this tell me? I dunno. Not very
conclusive as to the importance of jitter on HAGUSB clock.
Feb 05
------
Holy cow, will you look at the prices of ICL8038 chips these days! The NTE864
replacement for it just went up to $18. Shoot. This was a $3 chip when I
designed the FRYKLEANER. Gonna have to raise the price. Good thing I designed
it out on the newer machines.
Feb 03
------
There's a new USB DAC hitting the market soon. Looks very impressive and I'm
sure it will sound great, as it was designed by a superb engineer. But as I
read the feature list, I realized my CHIME DAC is either way underpriced or the
bargain of the decade.
$5999 DAC $1750 CHIME
--------- -----------
PCM1704U-K D/A chips, DF1704 X X
Tube output stage X X
Precision I/V conversion X X
Ultra-transparent output coupling caps X x (expensive polyprop)
Signal paths optimized for low jitter X X
USB converter reclocked x X (reclocking at converter)
USB & S/PDIF inputs X X
16/44.1, 24/48, 24/88.2, 24/96 X x (44.1 only)
Sorbothane feet X x (GOLD version only)
Belkin 5m USB cable X X (3m)
Optimum custom Power Cord X x (high quality shielded)
PC and MAC Software X O (not required)
Maybe I was too far ahead of the market? The CHIME has been out for well over
a year already. Quite by accident I ended up a first-mover in this area. A
lot of the DIY crowd has shunned it, probably because the advanced technology
is out of their reach. I dunno. Maybe it is cost. I think had I priced it at
$5000 sales would be way higher than they presently are. Too expensive for
DIY, way too cheap for the serious audiophile with money.
Tracked down a slight imperfection in the FRYBABY. Seems at MC output one of
the channels has more bass than the other. Found it was the dc reference level
for biasing the output stage than had enough microvolts of ripple that the
error got through. Make C13 larger and it goes away.
Working on the JFET differential stage for ARCHIVER and PICCOLO. Trying to
figure out why I am not getting the expected gain. Found error in my spice
model. Lambda was way off. Re-calculated it and made new typical model.
Simulations a little closer to reality, but real world is giving me 7dB less
gain. My new model looks like:
.model _2sk389 njf(vto=-0.7 beta=0.02 lambda=11m rs=8 rd=8 cgs=25p cgd=5.5p)
Anyway, back to lab to try a few resistor tweaks to see if I can fix both
gain and headroom issues.
Feb 01
------
Wrote the article for FRYPRO2 today. Pain in the butt. But this makes a
terrific DIY machine. Should be very popular. For anyone who prefers an
already assembled machine, that would be the FRY GOLD, due out later this month
for $500.
FRYPRO2 article
Doing my monthly business taxes (yea!) and realized I shipped four products to
Norway in January. That's gotta be some record.
Jan 31
------
Ok, FRYPRO2 up and running. Very nice project for you guys. I got the photos
done, just need to write up the article.
FRYPRO2 guts
Also made me a new movie. No viral marketing attempts with silly humor this
time. Hopefully, something a little more useful. This short demonstrates my
soldering technique for fine-pitch surface mount devices. Like the one used
in the HAGUSB. Could have been better (damn soldapult blocked the view), but I
did it in one take. Mostly practice. Thinking I can make more of these. It's
a 4MB clip.
How to solder
Does anyone do pro-bono work? I'd like to think so (besides lawyers). There's
this guy who bought a FRY PRO kit. Bought all the parts, but then got sick or
something and ended up in surgery. Didn't have the time or energy to finish
the project. Ok, I said I could do it for him. Several weeks pass, no word.
Then an email, he'll get the parts out soon, death in the family. Aye. So I
put it together today. A couple hours extra work. No big deal, but I can't do
it every day or I'd go out of business. But hey, god has a way of taking care
of things (if you just don't piss him off too much). You see, I needed to
finish my FRYPRO2 prototype but ran out of the dc jacks. And I didn't want to
place yet another Mouser order. Not for one part. And there it was! I
borrowed this guy's dc jack, installed it into my proto for a few minutes to
make sure it worked and to take photos. We both got what we needed.
Jan 30
------
Changed the drain resistors to 3.3k for maximum gain and biasing (debit SNR)
and tested the JFET differential stage. Gain is much lower than I had
simulated. Hmmm, what am I doing wrong. Everything else looked good. Very
good linearity, soft clipping, plenty output signal. Nice to test actual
hardware. Need to pour over data sheets. Maybe I'm not using this FET to its
advantage. Maybe higher current?
Started building the FRYPRO2. Simple design, try to replicate all functions
from the original model (which is no longer available). Boards fit nicely on
the back panel, better than I had expected. Fit is nice. It even looks
decent. Article to follow.
FRYPRO2
Jan 29
------
Dang, I got so much done here, but still missing the make XLR connectors. Hard
to find in stock. Already have backorders at both mouser and performance
audio. Asking if farnell really have them. If so, I'll import a few from UK.
Mouser says 2 more weeks until they get some in. That puts my FRY GOLD on hold
darn it. The unusual chassis design is made to go together easy, but very hard
to take apart (like a toyota dashboard). So I am not keen on soldering it up
until I have all the parts. Otherwise, it looks very good. Ready to go. MD
is really interested in it. Also holding up the ARCHIVER.
FRY GOLD
Did some performance testing on the ARCHIVER. After all, I need to prove out
some of the stages for use elsewhere. Not sure why, but gain came out low.
Something is wrong with the headamp section. Maybe I built it wrong. I'll do
another one to check out on bench, as it will become a PICCOLO. Anyway, most
of the functions work fine. Even the output gain trim was almost perfect, in
close enough to 2dB steps. Bandwidth was 16Hz to 400kHz+. Why it was so fast,
I don't know. Over the useful audio band EQ was flat. Gain was very low, at
52dB (58dB balanced). That's about 20dB lower than it should have been. Noise
was insanely low. I measured 100uV unweighted. Or 92dB A-weighted ref 5mV.
That is astounding. I was able to confirm via listening tests. Output
impedance was bout 600 ohms.
ARCHIVER front
Unfortunately, I put the XLR holes in the wrong spot. Otherwise, the
mechanical fit issues went really well. Everything else went together
perfectly.
ARCHIVER rear
Just look at the superb quality of the faceplate and knobs.
ARCHIVER closeup
Cool, just got my CYMBAL GOLD front panel in. Shoot. I messed up the holes to
the headphone jack. Oops. I remember placing them on grid, forgetting to re-
position them accurately later. I'll need to make some sort of large black
washer to cover up the mess. Hmmm, maybe a rubber shock mount ain't so bad
after all. It looks fine already.
CYMBAL GOLD front
The rear is very simple. Just an ac plug and two input connectors. This box
is huge.
CYMBAL GOLD rear
Fabulous article in the recent Entrepreneur magazine (page 96) titled "7
Secrets to Success". Written for small business owners, but the principles
readily apply to all aspects of life. I'm cutting this one out. Usually I'm
not such a fan of this rag as the graphic layout is confusing - sidebars
unrelated to the middle columes. Anyway, the money quote was:
"The greatest reward in becoming a millionaire is not the amount of money that
you earn. It is the kind of person that you have become to become a
millionaire in the first place."
7 Secrets
Jan 26
------
Well, the combined EQ topology works just fine. Spent several hours last night
going through all the equations to calculate new components. The result is a
bit more interactive. I can make it perfect for RIAA, but then as you switch
turnover, the cut gets affected a little. Same thing the other way. But hey,
I'm thinking it ain't no big deal if all the odd 78 EQ settings are a little
off. What's a 1dB error at that point. Better than 10dB without the settings.
And in those days, I doubt the EQ on the lathe was super accurate anyway. So I
think the combo passive EQ is an ok thing.
Off to the lab to build it. And dang, same headroom problem. Looks like it
doesn't really solve anything. It's the input that overloads. I might have to
rethink this entire approach, the differential JFET stage has such a limited
input range. Making it larger destroys the gain. Not sure where this is going
to lead. Been comparing to BUGLE on bench, and realizing just how good that
machine is. Wonderful characteristics.
BTW - just sold out of FRY PROs. No more. Bought the chassis for it's DIY
replacement, which will allow for more customization. Same basic circuit, new
chassis. No PRO half-kit, you'll just have to buy separate FRYKLEANER and
iRIAA boards. Should be able to write article next week. The FRY GOLD will
replace assembled versions. I think price will be $500, but you get twice the
output connections. It is also more robust and more visibly appealing.
Production starts next month. Might also sell this via MD.
Jan 25
------
Finally got ARHIVER up and running. Mostly. Still short those make XLR jacks.
Pretty much everything firing up the way I hoped. EQ is spot on. And all I
did was calculate it. Measures perfect. Seems a bit shy of gain, have not
measured, though. Overloading too quickly. The regulated wall-wart was super
noisy. Old FRYKLEANER wall-wart runs quiet. So functionality is there. I
even made my first recording. Got supply voltages tweaked in. A few spacing
problems with electrolytics too large. Also seems a tight fit with decoupling
films, which are not installed yet. On the whole, for a first layout, it is
remarkably bug-free and clean. Detected no wiring errors. Just mechanical fit
issues. Issue now is to look at gain distribution to improve overhead.
ARCHIVER proto
Yeah, it's definately a headroom issue. Ok except at high frequencies. I'd
like to have about 20dB extra at 20kHz. Should get the panels any day now and
I can button it up and do some careful listening. Burning-in too. First
impression was very smooth but lacking on either transients or punch. Vocals
were great. Something not quite right. I built another test board with the
EQ switched around. That was worse. Same thing happened during the Trumpet
development. Thinking about possible ways to combat this. Simple solution is
to lower current on JFETs, rebias the stages. Another choice is to add another
gain stage. Perhaps the best option is to swap the cut stage with gain trim.
That would combine EQs. Very common approach, but without the split EQ I think
the accuracy of the variations might end up interactive. Will require a lot of
work. Overall gain also seemed to come out a little on the low side. More
measurements needed. Fortunately, if I do combine EQ into one passive stage,
the front panel makes more sense, moving the gain trim to the right of cut.
Jan 24
------
Did some tube tracing for Romy. I discovered a really odd hysteresis in a 6C33
output tube. The good news is that it was supposed to be bad. So I made this
interesting video of the traces (VACUTRACE) switching from one heater to the
other. A 6C33 is two triodes strapped together internally, but with separate
heaters. Hence, you can drive both sides in parallel or one at a time. The X
scale is 20V/div plate, Y is 25mA/div cathode.
6C33 on VACUTRACE
Jan 22
------
Just played my best game ever of chutes and ladders. I swear, it was like 8
moves. I hit 3 or 4 ladders (starting with a 1), and then had all high number
spins. No chutes. Everyone else was still in the first 3 rows. Bang. I win.
Jan 21
------
Back page of stereophile has words of wisdom. From a guy named Barlotti, who
doesn't even speak english, but came up with this gem:
"I think that downloads and vinyl can coexist. It's the CD that may get left
out."
Jan 20
------
Thinking of getting an EMU-0404 and the spectraplus FFT software as pieces of
test equipment. I can then put them on my iMac in the lab. Or maybe my
laptop. Would give me some new tools for harmonic and distortion analysis. I
might even be able to do a full frequency sweep of distortion, not just the
1kHz analog test tone I happen to have. The 192k S/PDIF I/O will also come in
handy for any new DAC developments. Like the digital board for the RGP. A lot
of good capabilities here for just $500. Maybe I can somehow measure jitter?
Maybe I need to only buy stuff I need, not what I want.
Similarly, I'm bidding on some Garrard 401 turntables. Always wanted to put
together a table. The 401 doesn't look as cool as the 301, but are way
cheaper. Maybe I just paint it. There is some dude in Moldova that sells a
solid birch plywood plinth. All pre-made. Just what I want. It has to be big
because I want space to mount 3 or 4 arms. One mono for 78s. One MM, and one
MC. That's the idea, anyway. Maybe I should just pay off my credit card
instead.
Jan 19
------
Whoah, running out of FRYPRO parts fast. Only down to about 4 more sets of
chassis panels. And with the FRYGOLD replacing it, I think I will discontinue
the FRYPRO. But that leaves a hole for DIYers. They want that functionality.
The ROI takes too long, however, to recover the $1500 investment in panels. So
what to do? I know - make a FRYPRO2! Look, the plastic chassis had it's
problems with strength and durability. Hence, the metal GOLD chassis. All I
need to do to satisfy the kit builders is to offer plans on how to make a PRO2
using a non-custom chassis. And I found one. A nice metal sloping cabinet,
similar to the VACUTRACE, only smaller, no wood. Price to DIYer ends up about
the same. It takes a little more work, but offers the ability to customize and
add your own choice of extra connectors. I will make up a new manual for
FRYPRO2 that uses the original FRYKLEANER and IRIAA boards and offers all the
functionality you want. Plus a more solid chassis, stronger binding posts, and
easier finger access. I'll whip up a prototype you can copy. This strategy
will keep the product line full. Panel will look something like this:
FRYPRO2 panel
I keep thinking about the COMPRESSOR. Have this stack of schematics in the lab
so that they're handy anytime I need to do a debug on some machine. In there
is the schematics for the COMPRESSOR. They're beautiful. Haven't had the time
to finish this proto yet, but I plan to for two reasons. One, to prive the
output stage is that which I want to use for the RGP. Two, so I can sell it.
I have two grand in parts caught up in that thing. I even have two brand new
microphones sitting on the shelf unused. I'm really proud of that design. So
I keep wondering what else I can do for salvage. That is, without blowing even
more cash. The plan was to move on, as it doesn't really fit into my product
lineup. Advertising in a new market could be an expensive distraction from
where I am headed. But I keep coming back to this machine. It's a work of art
and could be a superb performer. And so I wonder, maybe I can sell it one at a
time on a custom order basis. That would eliminate the need to stock parts.
Sell it for about $5500 so that a build is worthwhile. A 3-week delivery time
is not so bad. I stock nothing. Not even circuit boards. This could work.
It also could add market and market clout (at least when it gets installed in a
few prominent studios). It could even turn into a cash cow. Also makes for a
great piece at shows. I'll ponder this some more. I hate to waste something
that is 95% complete already. I put in a huge number of hours on this already.
Jan 18
------
Saw this great quote in the latest IEEE Spectrum magazine regarding innovation
and invention (from Lucky):
"But great ideas do happen, as has occurred with many of the innovations and
achievements we celebrate as engineers - it's just tha they don't tend to get
scheduled or to come about because of a job requirement. Most often these
ideas come at unexpected moments when the originator is thinking about
something else or nothing at all. Perhaps while we are taking a shower in the
morning, a background pocess is grinding away in our brains, and a connection
is made while we ostensibly are thinking of nothing but pouring shampoo."
Nails it, as far as I am concerned.
Thar she blows! MD just selected to include the RIPPER in their catalog. I
hope they can sell a ton of them. Such a move eliminates the introductory
pricing of $400 to the MSRP of $650. This positions the stage nicely against
competing products. Trust me, this ain't overpriced. You get a lot for your
money.
Jan 17
------
Started assembling the ARCHIVER. Board is beautiful. Missing a lot of parts,
as I have the Mouser stuff on hold due to backorder. Won't ship until next
week. Also looks like the male XLRs I panic ordered from performanceaudio will
be late too. Sheesh. That holds up the FRYGOLD as well. Meanwhile, MD wants
to sell both the FRYGOLD and RIPPER. Not sure I'll offer the FRY as its open
frame chassis might not jive with their customer base. It was intended more as
an industrial machine. Not sure I am willing to start over with a chassis re-
design.
Got board installed into CYMBAL GOLD. Everything fit just as plannel. Need to
order front panel for it. Missing input XLRs and power switch. A perfect
match to the CHIME GOLD. In about two weeks I can have a music system again.
CYMBAL GOLD guts
PFO has good CES show coverage up online. Wow, new turntables everywhere!
This is both good and bad. Bad because everyone and their brother think they
can design a table. Most of these are nothing more than gaudy sculpture, a
visual statement. Good because it means the market is expanding. And they
will all need phonostages. Alas, I see no tables that will run at 78rpm.
Hello?
Jan 15
------
I sort of took the weekend off. Ended up going to the Sony Open golf tourney
to watch the kid phenom. Amazing watching some of the shots the pros do. On
18 we sat for awhile where the drives end up. Most hit the rough. Second shot
to the green was average 230 yards. These guys were hitting irons out of the
rough. Right in front of me, Ogilvy (I think) bounced it past the green. Then
Vijay lands in a fairway bunker. Second shot has to be 220 yards out of sand,
split two bunkers guarding green. About a 10 yard wide window. The marshall
standing here mumbles something about, no problem, he'll make it on. Cocky
young spectator says, I'll bet you $20 he won't. I think to myself, this is
just like the audio forums where some hotshot rookie thinks he's got shit and
disrespects the old guru. Well, Singh doesn't even take a warmup swing, just
whacks it. No spray, picks it up cleanly, flies forever, lands on green and
sticks maybe 10 feet from the pin. He he he.
FRYGOLD and ARCHIVER boards came in. So did the parts for CYMBALGOLD. Lots of
assembly work tomorrow. Panels take another week.
Jan 12
------
Just got the new issue of stereophile. The big news? Atkinson can hear again.
Ay ay ay. This was the one guy who's opinion that had some relevance to me. I
have to wonder how long the crud had been building up. This reminds me of
several years ago I heard Rush Limbaugh adamantly prescribe super-compression
for all the bumper music they put on the air, claiming it sounded way better.
A month later he goes deaf. Yeah, I'm gonna trust you?
Meanwhile, the buyer from Music Direct wants to sell THE RIPPER. I guess I
need to look into this possibility. It would require a price increase. The
question is how to maximize profit (and I'm not just talking dollars). When I
mentioned the FRY GOLD, he was interested in that, too. Hmmm. Oh, here's a
shot of the first proto.
FRY GOLD proto
Jan 11
------
Ripped apart my CYMBALs today and fit them into the new chassis. Actually, the
chassis took a bit of modification work. Holes, cutouts, countersinks, etc. I
mounted transformers after flipping the bells upside down. Looking good. Hey,
I only have one shot at this. This is gonna be one expensive headphone amp.
CYMBAL GOLD chassis
Meanwhile, waiting for parts to come in. Have another VACUTRACE to build. And
Romy sent some tubes to get traced. Yeah, always busy with something. No dead
time here.
Jan 10
------
New shipment of C2 boards just came in. All backorders have been sent. And I
took care of my fire backup. Put an extra copy of the flash key into the safe,
also copying data files to a private archive folder at my ISP.
Looking at the new Sweetwater catalog, Tube Tec has a new recording channel
that is quite similar to my COMPRESSOR. The main difference is that it is a
single channel (versus my stereo) and added several bands of EQ. Looks pretty
nice. Same price I had.
Tube Tec
Jan 9
-----
Ran some simulations to compare the hagerworth (green) filter to the standard
ones. A 7th order Butterworth (red) is close in attenuation characteristics,
except right around the -3dB point. After that the slope is the same. A 5th
order 0.1dB ripple Chebyshev (blue) type has about the same cutoff, but known
for poor transient response. As an audio or video filter, I was thinking the
hagerworth response would be a dramatic improvement. Well, after comparing
them, it is indeed better, but not night and day. That is, the other two
really weren't that horrible.
Hagerworth filter comparison
I was going to submit it as a design idea to EDN, but it's not really worth
the time (pun intended).
Buying parts for ARCHIVER, I discover why the male XLRs never showed up for the
FRYGOLD. On backorder fo 3 months! Dang. The exact part I design in, nothing
else will fit. Ok, so I search, discover this www.performanceaudio.com place.
Lots of parts and stuff. Had items cheap. Also a whole bunch of adapters.
Worth checking out.
Working out how the CYMBAL GOLD will fit together. Figure I turn the bells on
the trannys upside down, cut a new hole, and mount to bottom plate. Only the
boards need standoffs. Maybe 4", maybe 4.5". But it means I can't put any
controls or connectors down the centerline of panels. Easier to wire by moving
them up. Might look a little awkward, but simplifies the wiring. Adding a
headphone jack and hopefully I can wire it up for 4 ohm tap or similar for
lower gain. Yes, this thirty pound monster will be my headphone amp. The one
you've all been waiting for. I'll write up a DIY article once I tweak it all
in. Only problem is that I seriously doubt anyone will fork over $1500 on
parts for a DIY headphone amp. Anyway, ready to start drilling chassis and
mounting parts. Already ripped up one CYMBAL and rebuilding it with several
parts moved to the other side.
So I do a bike ride. Coming back this dude catches me and asks if that's the
back of the group. Huh? He takes off, I see a group of riders about 1/4 mile
up. Ok, I'll bite. Let's pull them in. Dang, this guy puts a gap on me so
fast I can't believe it. I kill myself for about four miles and thanks to a
red light I close the gap. Hey, these are the tri-moving guys I used to see
every Tuesday at this time as I drove my kids home from swim class. Finally I
get to ride with them. At the back of the line, it's not too much work, even
though we're flying 23+ into the wind. When we reach the turnout I ask them
who that dude in the white jersey was, as he flew right past them too. That's
the state time trial champ, they answer. Oh, ok. I feel old.
And so that brings me to the next subject, disaster recovery. Been doing a lot
of strategic thinking lately on business, marketing, products, etc. Well what
about disaster scenarios?
A) My bike gets run over while I'm on it. Who will then take the reins? How
does the business continue without me? Does it just close up shop? Does the
inventory have any value? Can anything be sold? Is my bookeeping properly
organized? Hmmm.
B) The office and/or shop burns down. Ok, I've been real good about backups of
all my data, keeping CD-Rs in a safe, a USB drive just for backup, and a thumb
key for backup of just data files. I can probably weather a hard drive crash
or two. There are four computers here I can use, all networked. I keep data
separate from operating system. It's not easy, as one machine runs NT, another
DOS, and then three XPs. Have to do that for running old schematic and layout
software. Anyway, fire will take them all out at once. Only the CD-R in the
safe might survive. Ok, I can see I definately need to upload data to the net.
I have 1G storage for my websites. Time I start using it. The other issue is
inventory. The replacement cost just for blanks PCBs alone is huge. I have
like ten grand sitting on shelves. Test equipment? It would take me months
just to get part of it re-started. Hmmm.
C) Al Kida stikes again, only this time real big. Maybe a city goes up in
smoke. Something that really puts the brakes on the economy. How does a small
business guy deal with that? Do sales go to zero? After all, this is nothing
more than the entertainment and personal pleasure business. People will focus
on necessities, not a phono kit. On the other hand, in bad times, historically
people spend 5% on entertainment. Same as they do in good times. So this is a
hard question to answer. I suppose there are conditions that would simply put
me out of business. Depends on how long I can weather a slow period. And this
is not my second job or part time work. It's my sole source of income. I have
three little kids to feed. Is it even possible to plan for this? One thought
I have is the value of my patents. The new mass spectrometer could prove very
good at poison sniffing, explosive detection, or other homeland security needs.
Ok, I don't exactly own the rights to these patents (nor have they issued yet),
but the company that does seems to be real good at getting government
contracts. If that is a valid direction, then maybe I should think about
submitting a patent application for my real-time 3d sonar idea. It's exactly
the sort of technology that is needed for harbor or ship defense. Sadly, out
of three tries I never got SBIR money for it (turns out to be a real insider's
game). Yet the invention still has a lot of merit. Might be worth forking over
the $3k or so to run it through the lawyers. Hmmm.
Jan 8
-----
Ok, I just ordered new panels and circuit boards for both FRYGOLD and ARCHIVER.
Ka-ching. At this pace I should have FRYGOLD on sale by the end of the month.
The phono should be up and running, hopefully debugged and singing by the same
time. Likely I'll have to make some osrt of tweak to tune it in. Then it will
be ready for production launch in February. If all goes well, I can send this
unit to Dorgay for his article on 78s. Everything right on schedule. Then I
can get this PICCOLO project moving. Right now I am leaning towards just using
4 AA cells. They're low impedance, cheap, plentiful, and a user can swap out
rechargeables if they want. Gives good flexibility and makes my life easier.
It also makes the system configurable to run from a 6V heater supply.
Also have this idea for a CYMBAL GOLD. But likely a one-off machine for
myself. I already have this big-ass chassis made for it. My thought is to
have it double as a headphone amp. I'll put the speaker binding posts and a
headphone connector on the front. Two CYMBALs fit inside this one box. It's
an odd configuration I came up with a year ago, with transformers on the bottom
wired up through the circuit boards, which are about 1/2 way up. Then tubes on
top. Everything enclosed. It's about a foot tall. It'll be my show amp. Can
post a construction article on how to build it. Probably the most expensive
$1500 in parts DIY headphone amp you can make. But hey, it will have better
bass than any other tube can amp out there. Won't cost me much as I can just
re-use the parts from my existing CYMBALs. Only need to buy a faceplate.
Jan 7
-----
I did my usual ride yesterday, 25 miles, several hills. Not long, but not too
short. Before I went, took off the tri-bars and shoved the seat back 1/2 inch.
I had it all rigged up for time trial geometry, which didn't really work. I
wasn't aero or efficient. Comfortable, but compromised. Well holy cow, the
difference was amazing. Handling was way better, my ass didn't hurt, and I had
more power. Unreal. All I did was shift back to road geometry, the way the
bike was intended. Everything was better. I suppose it is like changing caps
in an amp. The difference can be jaw dropping. And you hardly did anything.
Small changes can make a world of difference. There is no point to ever stop
tweaking.
Then I solved another problem for the ARCHIVER project. What does one do if
not installed in a rack? My idea was to make triangular brackets of some sort,
hopefully of wood. This would then have feet and damping for the chassis. It
also gets the circuit board off the floor (or shelf). So I walked around the
hardware store, looking at shelf stuff. Looked all over, you never know what
you might find. And there it was! In the bathroom department. A wooden
toilet paper holder. It was a perfect fit. Exactly the right size. A nicely
carved, sanded and finished wood mount for the whopping price of $5. Add four
stainless screws and the ARCHIVER mounts nicely. There are even mounting holes
for the expensive sorbothane feet I use on the TRUMPET and CHIME GOLD. Almost
comical how synergistic this is. Exactly what I needed. Sure, I could have
designed a custom piece. But I'm not in the business of making every part
custom. I buy off the shelf parts and put them together to make art. This
solution will be quite unique in the industry. Most importantly, it should
actually perform duties quite well. The added damping and vibration isolation
will prove useful in a phonostage.
I like to occasionally browse the 6moons new site. Helps you keep up to date
with the lates products.
6moons news
Anyway, I notice modwright has a new preamp. Sounds like a nice design, he
really did his homework. However! There is no picture. I clicked on the link
to the website and there was no information. Hello, Dan? You have to have at
least a photo of the machine. If not, you're announcing too early. Get some
pics and info online pronto.
I also see Kevin Carter does the "moon" audio stuff. Ok, I never heard of
them, but this is interesting. On the back it says designs and manufactured by
K&K audio. And it is chock full of Lundahl iron. He also does some of the Art
Audio stuff, the vinyl one for sure. This might be a good business model to
copy. He does all the design work, but lets someone else handle the sales and
distribution. He even uses someone else's brand name! Very interesting.
Maybe this is a better way to go. Maybe pushing HAGLABS myself is too much?
Jan 6
-----
Ok, so what about looking backwards again at 2006. I just did my yearly excise
tax forms. Cool looks like sales were up quite a bit. Good thing, as I didn't
put as much into consulting, so that went way down. I used to live solely off
the consulting gigs and the rest was mostly breakeven. Now the tide has
changed. Let's take a hard look at what is selling. The big suprise of the
year is the HAGUSB. Holy cow, I sold more of these assembled than I did BUGLE
kits. The BUGLE is no longer king of the hill in terms of units sold. The
digital stuff seems to be moving. CHIMEs are going, RIPPERs starting to take
off. Biggest winner in terms of dollars? VACUTRACE. Go figure. Used to be
TRUMPET, but that market window is gone. Great unit, but wrong mix of features
for todays buyer. CORNET continues to go strong. It has so much performance
per dollar, value is sky high. You can get some great sound out of that
design, which I think will end up being a timeless classic. Very clean, simple
circuit with boatloads of potential performance. Find the right tubes and caps
and it sings. Burn-in stuff also selling good.
So, what is NOT selling? That is just as important to help steer strategy. My
really good HAGCLOCK is a dud. At least the assembled version. Also the
assembled versions of CORNET2 and CLARINET. CYMBAL and OBOE are duds. This is
in terms of units sold, not any indication of their performance. Merely their
market acceptance and demand. I'm fine with that.
Good moves I think I made? CHIME GOLD. That's a much nicer chassis for that
sort of buyer. I think the FRY GOLD is also in the right direction.
Capitalizes on leadership in break-in and covers a dwindling stock of FRY PRO
panels. Dangerous move? The ARCHIVER. BUGLE PROs were not a big seller.
Perhaps I overestimate the variable EQ market niche for 78s? Or maybe I added
just the right mix of features and performance. The balanced JFET design could
prove a winner. Interesting to see how it pans out. Could be a lot of effort
and investment for nothing. Good move? The PICCOLO. Demand is already strong
and I haven't even made it. Even better if I make it retrofit into a CORNET.
Move I hadn't thought of? A new CORNET. Maybe it is time to update this
classic. Circuit will probably be very much the same. Difference will be
with packaging, a new chassis, maybe the PICCOLO headamp option built-in. How
about variable loading? Market demand for tube phono performance at this price
point is high. I'll have to mull this one over. Maybe a project for next
year. The question is, does the chassis have tubes sticking out or hidden
inside?
Jan 5
-----
Spent the night scanning old documents. Every once in awhile I get an email
asking me about something in one of my old technical papers or design ideas.
Well, a bunch of them were scanned in ten years ago at low resolution. At the
time I had very little web disk allotment and kept everything compressed. Only
problem is that they aren't quite readable. So I did high quality scans with
some photoshop processing to make them look and print quite good. Event the
popular snubber paper got scanned, as the old PDF did not display equations
properly. While I was at it, added a whole bunch of non-classified work I had
done. Good papers, good technical information. Just never before seen. Sure
wish I could add the papers covering my three latest patents. But since they
are still pending, I cannot divulge the information publicly.
I gotta tell, you I probably do an update to this website every single day, not
including blog. Sure, it looks pretty static, like it doesn't change much.
But I am always uploading corrections, a new testimonial, or something.
Seriously, practically every day I ftp upload something.
Finished the ARCHIVER layout. At same time, re-did the FRY GOLD layout and
panel too. Thinking I jumped the gun a little on that project. I hurried it
up with too much confidence. Well, no I pay the price. What I normally do is
buy all of the parts before I finish the layout. That gives me a chance to see
the actual part in question. The data sheets don't tell the whole story. Case
in point is these new XLR connectors. Turns out the required hole size is
twice what they specify, and that bare conductors touch the board. If one of
these scrape through the soldermask, you get an unwanted short. No more
shortcuts! I have to make so many little changes to the FRYGOLD stuff that I
may as well not even complete this generation prototype. Just save parts for
next layout. The circuit worked, it's just a matter of proper fit. Very
difficult 3D construction, this sandwich design. Sure, each revision you learn
something, but this is $300 I'll never see again. Sigh, the cost of
development. Anyway, here I am ready to order two new proto boards and three
new panels. Maybe I'll wait until Monday to pull the trigger. Give myself a
little time over the weekend to reflect and mull.
ARCHIVER layout
Jan 4
-----
Ugh, I spoke too soon. What a rats nest this next section turned out to be. I
must have spent two hours just moving around the five EQ capacitors. Such a
domino effect, every time I try a new approach, the impact ripples across the
board. Ended up ok, but I still have a mess to unwind with the output stages
and phase switch.
FRY GOLD panels came in. Very light in weight, I wonder what type of aluminum
alloy this is. Anyway, the concept looks good, but I had some fit problems.
First, the holes for the XLRs were too small, I had to file the tabs down.
Then, the big insulators on the binding posts ran into some oversized
electrolytics I had installed. Other than that, it's coming together. Just
forgot to buy male XLRs. Now I have to wait again. Dang. Anyway, looking at
overall improvements, I think I'll add some standoffs for extra strength in the
construction. But the best place to put these is right where I have the output
amps, so I'll split them up and move to open section. Shux, that means a lot
of changes in a new layout. Typically, it takes me 3 tries to nail a board to
perfection. And it is happening again.
So I did something odd today. Something I never expected. I just sold 100
BUGLE boards to some guy who wants to sell full kits. What was I thinking?
Will this hurt my sales? Or bring in more attention? Seriously, how many of
you DIYers don't like the half-kit concept and would rather buy a box full of
parts? Some, I suppose. I wonder what this guy will charge. Anyway, he's
agreed to use "designed by Hagerman" with links to my website. Did I just
shoot myself in the foot or make a good sale?
And on to mull my plan for 2007. Do I just react to the market or try to lead
it? That's where I ended last year, trying to shore up market position in
areas of success. That's why the FRY GOLD. I only have enough PRO panels to
last another year of kit sales, so I replace the PRO with the GOLD. Better
design, more performance, less time to build. Second, the ARCHIVER. That
came out of nowhere, but it positions me with a new product in the phono
market. It also develops technology that will use to introduce the PICCOLO,
a half-kit phono headamp. Such is exactly what is needed by many, and fits
well with the CORNET. In fact, I'm thinking of making it installable inside
the CORNET. Sadly, it won't work with the C2, as input cables route past the
power transformer. It picks up hum. I tried it. The original C2 has step-up
trannys and I could not get them to work. The problem was that I had already
commited to that chassis configuration. An unfortunate hole. The ARHIVER
offers a ton of the most desired features and then some. Hopefully the sonics
are as good as I expect. For $1000 street price, it'll be a giant killer.
Seriously, look at the new ASR phono. Seven grand for a plastic box and some
opamps. The Groove? Five grand for a plastic box and some opamps. Ok, so
ARCHIVER came out a lot costlier than I had expected. But I believe it has
some real market potential. All depends on how well it gets marketed.
That's part of the new plan. Kits do not make a whole lot of money. The old
method was to design a kit and product at same time. That wasn't cutting it.
Now I copy the others and design the product first. Then spin whatever
technology got developed into a low cost kit. First example is to be PICCOLO.
So 2007 is pretty simple. Just get the FRY GOLD, ARCHIVER, and PICCOLO to
market. That should maintain and strengthen my positions for burn-in and
phono. VACUTRACE remains on top of that hill. I'll be shifting the UFO to
Galibier for production (with some mods). That should solidify my lineup.
What's missing? The digital stuff. Sort of. The USB side is enhanced by the
ARCHIVER, and CHIME GOLD, RIPPER, and HAGUSB are still viable and relatively
new. Yeah, my logic is rambling here. But it looks to me like my main markets
of 'phono', 'usb', 'burn', and 'tube test' are covered for 2007. The plan
behind the plan is to create time for RGP development. It will be costly. I
have not solved the financials yet, but distribution is in process.
Marketing plans need work. I'll use my space in TONE for a 'gold rush' ad,
which shows the ARCHIVER, FRY GOLD, and CHIME GOLD all at once. They need
some press or nobody will know they exist. Second, I think I can buy a one-off
ad in aXp for the RIPPER. That's more their style. Need to think about more
exposure in other areas. Promotion is costly, but without it, I'm broke.
Tomorrow maybe I consider a 5-year plan.
Jan 3
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Still not done with ARCHIVER changes and improvements. Here's the latest. I
added the 316 ohm resistors to the 10nF cut setting (RIAA) to give the zero at
50kHz, just like my other phonostages. But only on this one setting. Not to
be shown in schematic, along with a few other things. So if anyone tries to
copy the circuit, they will run into several problems. Hint, don't copy it as
drawn. Added a ground hole next to USB chip. I am adding a wire to ground the
xtal case (maybe this reduces noise?). Not only that, but I'm going to wrap it
across the top of the USB chip as sort of a shield. And since I have a 3
position switch on the input, why not use it? I could have added an extra mono
RCA, but instead chose to have two modes for the stereo inputs. The middle
setting is now a mono mode for the stereo cart, by shorting the channels
together. This should give for a better mono read of a groove by a stereo
cart. Not that I recommend it (use a mono cart!), but it is a performance
improvement. Changed standoffs to #6 size. Added handles with ferrules,
carved out sections of panels to remove anodize and get solid ground
connections for both front and back. Even with anodize on handles. Color
scheme is still gold with black knobs, black handles, black pushbutton cap,
blue LED via fresnel lens. Also realized that if I make cutouts on the rotary
switches, I can shift their height from 0.55" to 0.5", which makes for perfect
fit with standard standoffs! Of course, all of this comes at a cost. The dang
panels are now up to $150 a set. Now I'm wondering what to do about feet, as
most of these will not be rack mounted.
Oh man, just did another trace routing session. What a pain! Had a lot of
trouble getting the routes to the rotary switches clean. Everything is so
tight, took me awhile to find a rearrangement that worked across the board.
Eventually, pulled some tricks to ease routing and keep ground plane mostly
uncorrupted. Like adding jumpers. The big break came when I change a couple
of 1/4W resistors on the back side to 1W size. That opened it all up. I'll
still use 1/4W resistors, just on 0.6" hole spacing instead of 0.4". And just
these few. Anyway, after many ripups and retries, I got it. Layout mostly
routed. Just need to do output stage and phase switching. A few more hours
and it'll be good to go. Power routing went down the middle no problem, just
as planned. He's how she's looking:
ARCHIVER traces
Jan 2
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Ok, got the ARCHIVER layout placement and wiring done. That's a LOT of work.
Turning into an absolute piece of art. Everything falling into place
perfectly. I keep finding things that should have gone into the schematic,
panel, or specification. That's why I desing everything in parallel. Like,
duh, I forgot to put in a mute function. And it was super easy to convert the
phase shift to have a middle "zero" position. This will prevent pops and tics
on power up and down. All without having to add a bunch of extra circuitry.
The size did increase to 1.5U tall, which I think is acceptable. It it still a
convenient rack mount if desired. Connectors out back. I added standoffs for
both front and back panels. This adds both rigitidy and more importantly,
electrical grounding, something I want for maximal shielding. Only drawback is
that there are now visible screw heads. Oh well, it's a compromise for
improved performance. Oh wait, I can just add handles.
Anyway, layout is tight and clean. Dc-dc converter and USB sections are far
away from phono amplification. Many levels of supply filtering. Tons of big
polyprop caps. Probably 22 of them hanging off the back side of the board.
ARCHIVER layout
Thinking of how to offer this as a kit. So many custom parts, cannot be a
half-kit. However, it could be a full-kit. Depends on demand, which I hope to
be strong, as this makes for a super regular phono (for the 78s). This is the
TRUMPET architecture done in discrete low noise JFETs. All balanced. Indeed,
this should come close to the TRUMPET sound. I would not be suprised if this
also ended up as class A. It has so many good features. Only two of the
controls are for variable EQ. The other six are needed anyway. Only real
drawback to this circuit is having so many switch contacts in the signal path.
So who would buy a top-flight SS phono kit? Here's my idea. I could do the
same non-inventory method as the half-kit, but still deliver everything you
need. Basically, I charge you $500 (or whatever it is). Then I ship PCB,
instructions, and maybe some hardware. I also order the parts from DigiKey,
only have them shipped straight to you! I do the same with the panels. You
still get a full kit. It just happens to come in three shipments. Is such a
concept valid? I would not have to charge much of a markup. I could also
offer then front not just in gold, but red, blue, green, bronze, and silver.
Is this something anyone would be interested in?
ARCHIVER front