Subject: Komet amps Subject: Re: Komet amps Subject: Re: Komet amps Page 1 of 14 Untitled ...

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From: scott w ([email protected])
Date: 10/12/2001 3:09 PM
Subject: Komet amps
Anyone have schematic/parts list for a Komet amp? They sound awesome but can't afford $3000
price tag. Thanks!
From: Matthew Springer ([email protected])
Date: 10/12/2001 3:58 PM
Subject: Re: Komet amps
Scott,
Schematics for production boutique amps are probably tabooo around here especially if we, the
grizzled mapage veterems, personally know the builder (not to mention nobody wants to take
apart their 3k amp). The gentlemen in question who builds these marvelous beauties DOES post
around here so, most folks will probably not publicly release scematics even if they have them out
of coutesy.
But not to leave you completely in the dark:
The general approach of these amps is centered around the plexi circuit with some a Ken Fischer's
tweaks. The OT is a big part of these amp's sound and they get them from Joe over at:
http://www.obsoleteelectronics.com
You might wan tot take a look at the design for the Espresso TrainWreck amp as posted over at
blue guitar to get an idea of what Ken's general thnking is.
-Matthew
From: hogy
Date: 10/12/2001 5:06 PM
Subject: Re: Komet amps
Look, fellows, I don't know how this keeps coming up, but Komets DO NOT USE, nor have they
ever used, Obsolete Electronics output transformers. I should know this, I build them.
EVERY aspect of the Komet OT is completely different from the OEI Plexi OT. The Komet OT is a
proprietary design by Ken Fischer.
Having said that, The OEI Plexi OT is the finest transformer for a MARSHALL I've ever come across.
I put one in my own '67 Plexi, and it sounds better than the original.
The Komet circuit is entirely different from a Marshall Plexi circuit, and not based on it.
Besides that, I appreciate the respect shown here. Please do not give away our stuff, let us pay off
the bills first.
Hogy, Komet Amplification
From: jaysg
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Date: 10/12/2001 6:02 PM

Subject: Re: Komet amps
The OEI Plexi OT is the finest transformer for a MARSHALL I've ever come across. I put
one in my own '67 Plexi, and it sounds better than the original.
Impressive vote of confidence considering the source. :)
From: SpeedRacer ([email protected])
Date: 10/12/2001 6:22 PM
Subject: Re: Komet amps
I'd only add 3 things to what Hogy said:
1. I Don't how that rumor about us supplying Komet started but I sure as heck did not start it, and
I do try whenever I see it to clear it up. I wish we did make them, but we don't. :) We have NEVER
made trannies for Komet. Not even one. I hate saying that ;) but it's absolutely 100% true.
2. to Hogy - glad you like the 50W OT in your amp! Thanks for the kind words! I love a happy
ending.
3. to the original poster: try the amp out before you decide what it's worth. Consider the time and
effort involved in designing it, testing it, tooling up, building them and bringing them to market.
It's not cheap quick or easy. Let them, and the other boutiques, pay the rent. It's pretty expensive
just doing a couple trannies.. a whole amp can be $$$.
From: Matthew Springer ([email protected])
Date: 10/13/2001 5:14 PM
Subject: Re: Komet amps

I don't know how this keeps coming up, but Komets DO NOT USE, nor have they ever used,
Obsolete Electronics output transformers. I should know this, I build them.

Hogy,
I sit corrected. I guess you learn something new every day. Somehow I must have gotten your
design and the M&G stuff conflated. Humblest apologies for propagating false info....
-Matthew
From: Mook ([email protected])
Date: 10/12/2001 6:28 PM
Subject: Re: Komet amps - free amp!
Actually, you can get a free amp if you purchase the schematic. The schematic costs $3,600 and is
available from a number of authorized dealers across the US.
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The Express is not based upon a Marshall, actually it's more of a Fender "topology". I'll leave it to
you to figure the rest out.....
Remember, the amp is free!
Mook
From: momitch ([email protected])
Date: 10/12/2001 7:29 PM
Subject: Even if you had the schematic...
Even if you had the schematic, it would be very hard to build an amp that sounds just like the
Komet since you have no idea what transformers they use. Actually, the basic topology of the
circuit is no big secret. It goes something like this:
gain stage -> tone stack -> volume control -> gain stage -> gain stage -> PI
I will leave out the values for the resistors and caps used in the circuit, although I know what they
are. The only parts of the circuit that are anything like a plexi Marshall are the PI and the first gain
stage. The tone stack between the first two stages is like a Fender Blackface amp, althought the
cap values are different from the Blackface values.
I'm still not sure why everybody gets so upset about the release of schematics. If someone really
wanted to go into business and produce copies of a Komet, they could just buy a Komet and clone
it. Also, people around here treat the Trainwreck/Komet design like it is some sacred thing divined
from God. Every part of the circuit is copied from earlier Fender/Marshall designs. It's a cool
design, but it's not revolutionary by any stretch of the imagination.
Morris
From: Joe L ([email protected])
Date: 10/12/2001 9:33 PM
Subject: Re: Even if you had the schematic...
I'm still not sure why everybody gets so upset about the release of schematics.
Purely and simply because Hogy asked us not to.
I spent an afternoon at his shop and he is just a nice guy trying to get a start on a legit product.
Yes, the circuit is simple but it is the boiled down essence of what you want in a amp and is tuned
quite well and built very nicely. Because of the simplicity of the circuit, EVERY part makes a big
difference in the sound and Hogy has managed to tweak the design to get the most out of it.
And I did see a stack of transformers and no, they aren't OEIs. I would know, I have 3 OEIs :).
..Joe L
From: John/B.F.EGYPT Guitars
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Date: 10/12/2001 11:03 PM

Subject: 'Effin Napster rats...
Remember Junior, "sharing" only rules when it's not your stuff. Sharing without the permission of
the owner is theft. Backdooring a web neighbor who has been generous with his experience(not to
mention COOL pics of finds)is low and shows a distinct lack of "home schoolin'". "Share 3 grand
with the man, and i'm sure he'll be happy to "Share" you an amp. Now, BACK TO THE BENCH!
From: Max ([email protected])
Date: 10/15/2001 5:30 PM
Subject: Re: 'Effin Napster rats...
Dear Mr John!
Didn't you "share" a guitar design in the old days,with Mr Leo Fender?You know the drawing N° rft
04/01 Drawn By Mr Maurice Belando?Didn't you have legal isues with the Fender company?Or
else,your Egypt guitars is not the Scotish one then!
All rrright Beig man?
Best regards.
Max.
From: Jason ([email protected])
Date: 10/15/2001 6:07 PM
Subject: Re: Even if you had the schematic...
Joe L,
"And I did see a stack of transformers and no, they aren't OEIs. I would know, I have 3 OEIs"
Straight up: OEI is some pretty impressive Iron, IMO. I love mine. I am working on a circuit which
compliments it a bit nicer than my original(not that it can't hang--I just like to try to maximize the
potential as much as I can). Along with the fact that it sounds absolutely wonderful, the price is
also very friendly(especially when considering how good it really is). As for Komet trannies, I have
no idea who makes them, although they look identical to the Pacific Iron(for my proto), which looks
very similar to some Schumacher Iron which looks similar to Carl Zwengel's iron he used to sell.
Anyway, from what I have gathered from Ken, he used to use "off the shelf" Iron when the first
Trainwrecks were born. He has mentioned using custom Iron throughout a good portion of
Trainwreck history, though. I believe that he happened to really favor Stancor Iron and Pacific Iron.
Personally, I would shoot for the OEI Iron because it is #1 easily obtained and the sound quality is
right on par with the Pacific Iron, IMO. Heck, with a complimentary circuit(tweaks), Hammond Iron
can sound pretty damn good too. Anyway, I think that most of us here could probably make just
about any Iron sound good because most realize that it is the entire balance of the design that
really counts, not just some magic part(s). For EL-34's running at 390 - 420 VDC, I like a 3.4K-6K
load, depending on how it is setup. Specifically, I run them at 410 VDC @ 6K and really dig the
headroom and super responsive power amp. FWIW, I prefer the CF circuit to the overly
compressed(sorry) 3 gain stage Express/Komet/Liverpool topology. I think the Rocket was Ken's
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coolest amp. Next would be the Express. BTW, the Komet has a lot of "something old--something
new" in it's design. A great deal of the discrete stages/mechanics were obviously borrowed.
However, I should point out that they were put together in a complimentary sequence which
produces a fine amplifier. Pure Ken Fischer. Hogy and his guys construct them, but Ken was the
man who dreamed it all up. Simplicity really is more brilliant than complexity when the simpler
route outperfoms the complex route on every level. Now, how about my EL-34 duet in fixed bias
driven by a LTP driven by a CF based preamp lacking tone controls with just a volume, presence,
and cut control tweaked specifically aroung OEI Iron....
Jason
From: Trace - Voodoo Amps ([email protected])
Date: 10/13/2001 3:24 PM
Subject: The effects of releasing a
I'm still not sure why everybody gets so upset about the release of schematics.
I know that releasing a schematic seems harmless enough on the surface but I think you're only
looking on the surface verses looking at the over all effects. I know is seems like we're sharing
some cool info with others but all too often we forget (or do not take the time to realize) that
designers are people too and it's very important to remember that. Designers also have family's to
take care of, children to feed, bills and loans to pay, a business to run (not to mention paying for a
place to live, etc., etc.).
As the natural order of things go...if the schematic is released then someone would post it
somewhere on the web (as that always happens). How does this have any effect on the designer
(Hogy in this case)?
Let's preface this by saying that every major amp company does in fact monitor these boards as
well as the web in general. Posting the schematic on the web means millions of people will see it
but more importantly large amp companies will also have access to the schematic as well as
homebrewers.
In a perfect world everyone would be fair and honest but in today's world we cannot trust everyone
to be fair and honest (sad but very true). If a larger company copied the schematic (which does
and has happened through amp history) and mass produced the amp, which would most likely
allow them to sell the same basic amp for 1/2 the price, then that would certainly harm Hogy's
business. Again, amp designers/builders are people just like you and I are.
If someone really wanted to go into business and produce copies of a Komet, they
could just buy a Komet and clone it.
If the schematic were available on the web then why would anyone really want to spend the money
to purchase the amp(to reverse engineer it) when the schematic is free?
Also, people around here treat the Trainwreck/Komet design like it is some sacred thing
divined from God. Every part of the circuit is copied from earlier Fender/Marshall
designs. It's a cool design, but it's not revolutionary by any stretch of the imagination.
Beauty is in the eye of the beholder. A lot of has to do with the fact that Ken F. was one of the first
techs to share a great deal of info on tube amps with the public (generally speaking of course) so
people have a great deal of respect for him.
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As far as revolutionary: I'm not saying it is or isn't revolutionary and I do not feel that it's my place
to comment on that one way or another. However, an amp is a sum of the whole and when you
change one part it effects the over all tone. Ken (to my knowledge) is the first person to parallel
two caps together in a guitar amp (where the signal goes into the PI's grid) which creates a phase
shift and therefore sounds and "feels" different. is he the first person to actually parallel two caps
together? Of course not (ha,ha) but he did use it on a guitar amp and it does sound pretty cool in
that section (2=.01's in parallel). I did speak with a Neve tech about this and some of the older
more sought after mic pre's also did this.
I'm not trying to be confrontational but rather I'm just trying to give you another way of looking at
things.
Trace
From: Ray Ivers ([email protected])
Date: 10/13/2001 4:30 PM
Subject: Re: The effects of releasing a schematic...
Trace,
Wow - excellent post! I have just a couple of things to add:
1) Patents. When you release a schematic, you may get to find out (possibly in an unpleasant
manner) if the Fender-type tone stack or the long-tail-pair phase inverter you're using has been
patented (these are just examples, but honestly, would anyone here be surprised if these items
were patented?). In addition, you may suddenly find that any truly unique stuff you have in your
circuit (yes, I believe that there is something new under the sun - lots of stuff, actually) has
suddenly been patented or used in another amp design, as you mentioned in your post. I know
that there are ways around this, but does anyone really want to take the chance, and expose
themselves to this kind of stress? Non-disclosure is the best protection (the only protection?) from
this type of thing IMO.
2) Unwanted circuit analysis. Let's suppose you post your circuit, and then someone looks at it and
doesn't like what they see; in their mind, this circuit's just gotta sound terrible. Or - God forbid! -
you use solid-state devices anywhere in the amp. It's possible that this person or persons will then
feel free to post on the Web a 'review' of your design which may then be soaked up by others, and
presto; your design, and therefore your perceived skills as an amp designer, may get a bad rep,
possibly even before the circuit has been built and tested. Again, non-disclosure is the answer IMO,
forcing people to listen to a sound clip or actually try out your amp before commenting on it.
Anyway, just had to vent. ;)
Ray
From: jaysg ([email protected])
Date: 10/13/2001 5:37 PM
Subject: Re: The effects of releasing a schematic...
Ken (to my knowledge) is the first person to parallel two caps together in a guitar amp
(where the signal goes into the PI's grid) which creates a phase shift and therefore
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sounds and "feels" different.
oh that hurts....techno tidbit from Hell! Now I'm going to have to ask my EE mentor for an
explanation. There shouldn't be any phase shift different from just using a 2x value. :( They should
just add. Is this about figuring out which end is the foil outside and aligning them? You'd have to
model the cap as an RLC network, where the R & L are pretty dinky.
Trace, I believe you, but it goes against the grain. My head is reeling. What you can learn in this
place...
From: SpeedRacer ([email protected])
Date: 10/14/2001 4:12 AM
Subject: Re: The effects of releasing a schematic...
All I have to say about the parallel cap this is this:
I didn't think it would do much (if anything!). I kinda thought it was whacked. Maybe my buddy
Trace had sniffed too much solder?
Well, Trace came by the ranch one day.. we were goofing off trying each other's amps and I gave
him the benefit of the doubt... And he made a believer out of me. We put one of my cap sub boxes
in parallel and we swapped values around (for the parallel cap) and took the box in and out... I
heard it. I didn't want to hear it.. I just did. It just adds this 'girth' to the tone, a "3D" thickness
that is subtle but undeniable IME. There are some values that seem to work better than others, (no
big shock) but the best thing to do is try this yourself, A/B with the extra cap in and out and find
the value that suits you best..
From: rmike ([email protected])
Date: 10/15/2001 3:32 PM
Subject: Re: The effects of releasing a schematic...
I thought this also had to do with using two different types of caps also?
For example, using a silver mica 250pF and a ceramic 250pF in parallel instead of a single ceramic
or single mica 500pF? Maybe a bad example, but hopefully you see my point.
Mike
From: ChrisM ([email protected])
Date: 10/15/2001 4:12 PM
Subject: Re: The effects of releasing a schematic...
This may ba caused by the extra inductance that two caps instead of one might have. This would
roll off some highs I think, but not a whole lot more, and that slight difference could make it sound
"thicker" the phase difference between to caps of the same value and type should be
imperceptible. Of course if they are of different values and types, then the phase deal could be
true. Remember, capacitors are only mainly a capacitor over the frequency range they are
intended to be used at, they also have inductance and resistance, which begin to show up whne
they are used in ways they weren't designed for.
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-ChrisM
From: Justin Thomas ([email protected])
Date: 10/14/2001 12:06 PM
Subject: Re: The effects of releasing a schematic...
I think it would also be a fact that if some company mass produced Hogy's (or anyone here's)
design and millions of people bought the cheap one, the customers wouldn't be able to tell the
difference. I think it takes a special person to recognize the heart that goes into it, and I think that
comes through in the tone, but the general guitar buying public doesn't realize that. Don't know if
that makes sense. I guess I'm trying to say what Trace said-designers have feelings too, but most
people don't care and can't tell the difference anyway. Which is why it's so important for us to
spread the Gospel! Justin.
From: Ted B. ([email protected])
Date: 10/14/2001 4:26 PM
Subject: Re: The effects of releasing a schematic...
After playing the amp and being made privvy to some of what is done 'between the lines' to make
the Komet what it is, I can say with sincerity that unless you used the same transformers, top-
quality parts and other tidbits employed in the making of the Komet, a 'clone' made from a
schematic may very well not be an accurate repro, and would not be a fair representation of the
real amp.
Due to this, it is advantageous for the Komet guys not to release a schematic, if for no other
reason, to retard the possibility of someone making a cheapo 'clone' and advertising it the be the
equivalent of the real deal. After all, Marshall does this with their repro plexi amps, and I need not
say more where that is concerned. I'm sure the Komet guys don't want to see this happen with
their fine product. The Komet is a fabulous item, and I assure you that it could not be done better
than it is.
From: Dave K ([email protected])
Date: 10/14/2001 11:25 PM
Subject: Re: The effects of releasing a schematic...
Reverse engineering a competitors product is nothing new in any industry.If anyone thinks that the
major manufacturers are surfing the net hoping to find a schematic for a boutique amp,they don't
know much about business.Any company,large or small,will simply buy the product and tear it
down.
Where the major companies always fail is cost cutting their product to maximize profit.Any of us
who have to fix the mass market amps will tell you how bad some of these products are.If a major
company tried to clone the Komet,all of the corner cutting done by the bean counters will insure an
inferior product,one that will never sound like the original.
One last point on pricing.Some players will never understand what goes into producing a truly
handcrafted amp,complaining about the cost versus the mass market gear.I wonder how many of
these guys have ever bought a new car.Chances are they lost more in value as soon as they drove
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it off the lot,than what a an excellent hand built amp or guitar cost.End of rant! ;)
From: momitch ([email protected])
Date: 10/15/2001 2:32 AM
Subject: More thoughts on this issue
Dave's post is excellent. Anyone who has posted the idea that the release of a schematic would
somehow trigger the mass cloning of Komets is not thinking the issue through. Anyone who wants
to clone a Komet (or any other desirable amp) for profit will simply buy the amp, blueprint it, then
sell it on Ebay to some sucker who will pay retail for something slightly used. The only real threat
to Komet is the hobbyist who might decide to build one for himself rather than buy one, although
guys like that would probably never shell out $3000.00 for any production amp, even if it was
worth it.
I remember a while back when a schematic for a Dr. Z Route66 was posted on the Blue Guitar site.
The amp had just been released and there were a number of posts here discussing what the
topology of the "new hot" amp might be like. After the release of the schematic, people made the
same arguments and complaints they've been making in this thread. Nothing ever came from it,
except for the renewed interest by some homebrewers in the EF86 and ultralinear output stages,
which was a cool thing.
It seems to me that some people here are just a little too paranoid about the schematic issue. I'm
thankful that all the cool Fender and Marshall schematics are readily available, as it helps me get
ideas to tinker with in my free time. Remember, it was the schematics from those amps that gave
us the Komet in the first place.
I hope I haven't offended anyone here. I cherish this place!
Morris
From: Ray Ivers ([email protected])
Date: 10/15/2001 3:52 AM
Subject: Re: More thoughts on this issue
Morris,
It seems to me that some people here are just a little too paranoid about the schematic
issue. I'm thankful that all the cool Fender and Marshall schematics are readily
available, as it helps me get ideas to tinker with in my free time. Remember, it was the
schematics from those amps that gave us the Komet in the first place.
I, too, am very grateful for all the schematics available on the Web and elsewhere... don't know
what I would have done without them, they were a huge part of my learning experience.
When it comes to my own designs, though, somehow it's a little different. I'm sure that most
people that have come up with their own, unique circuits can understand what I mean, whether or
not they have chosen to disclose. I freely share a lot of stuff, but there are some things I've chosen
not to... just a choice I've made, possibly subject to change in the future. I completely respect the
decisions of both those who have chosen to make their designs public, and those who have not.
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And if all the non-published designs are inevitably derivative, then they're already available in
piecemeal form, right? :)
Ray Ivers
From: momitch ([email protected])
Date: 10/15/2001 4:33 AM
Subject: Ray, are you a...
professional amp designer? Do you make a living designing and building amps? If not, why would
you care if any of your designs were made public? They would only serve to help and inspire
others, especially guys at places like Ampage. I understand that some like to keep their ideas
secret, but I don't understand what the reasons are for this. If it can't hurt you, why not help
others? Isn't this why we are here at Ampage?
"And if all the non-published designs are inevitably derivative, then they're already available in
piecemeal form, right? :)"
Well, of course this is true. I never meant to imply that the melding of different design ideas from
Fender and Marshall (as found in the Komet) wasn't an incredibly cool accomplishment; it is. You
have missed my point. If the Komet schematic was released tomorrow, do you honestly believe
that Komet Amplification would suffer somehow? Nobody here has made a compelling case for why
or how this might happen. I think it might spark more interest in amp design and building by
homebrewers and hobbyists, which is a good thing. It's why Ampage exists!
From: Dr.KT88-6SL7 (pdebs@mdc-
Date: 10/15/2001 10:03 AM
Subject: Devices
I have a GE toaster which doesn´t work. Can anyone point me in the direction to find the
schematic. I am also looking for a Watr Pic schematic. I have decided to never buy mass produced
electronic devices, I will clone everything.
Dr.dr.KT88-6sl7
From: Gabriel E. ([email protected])
Date: 10/15/2001 7:24 PM
Subject: Re: Devices
Dude, GE toasters SUCK! What the hell are you thinking? Everyone knows Proctor Silex toasters
are the real deal - they make "browner" toast that you just can't replicate anywhere else.
Gabriel
From: Trace - Voodoo Amps ([email protected])
Date: 10/15/2001 2:05 PM
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