Buying an Amp Just to Reverse Engineer?

[pdf64]

'Fender borrowed Western Electric and RCA circuits'

From the Tone Lizard http://boyercentral.net/ToneLounge/www. ... mework.htm :
'Even the fabled tweed covered Fender Bassman amplifiers into the 1950's still had a little sticker inside the cabinet which read....."Licensed under U.S. patents of American Telephone Company & Telegraph and Western Electric Company, Incorporated, for use only in public address systems, ...systems for distribution from radio broadcast receiving sets or musical instruments...". Take two guesses as to whose vacuum tubes Fender used throughout their early years (and not because they had the tone!). RCA forced you to license a circuit design from them and pay royalties.'

So it wasn't Fender borrowing from RCA but rather RCA enforcing their IP of amplifier circuits. Pete.

[renshen1957]

[
Dr. Z's Carmen Ghia is allegedly from the Hammond Reverb Amp or as TDPR multiple posts a "straight across AO-35 clone" with a mid tone circuit from Matchless.

Renshen 1957 I am a contributing member of this forum, and I'm sick of the posts here stating I nicked Matchless's tone circuit.
The first Ghia was sold in 1988 that pre-dates any example of Matchless
using anything like the tone circuit I designed in the Ghia.
Matchless borrowed from me, I know that is a shock to some but a fact.

Yes the Ghia was based on the Hammond AO-35 a fact I have many times stated in interviews, but I turned that useless amp into a pretty cool guitar amp. A technic of DIY that has been copied ever since by many builders.

Verify your facts my friend before you accuse me, or post an alligation about me. Sorry if this seems strong but if I don't defend these lies they become fact in eye's of many.

DR.Z

Dear Dr. Z,

A bit touchy on the subject, aren't we? I can understand your being cheesed off a bit about, it.

I wouldn't exactly say the Hammond Amp was useless, (unless you are referring to guitars) I played through a number of them as an Organist.

As to the quotation I cited is from TDLP, have you brought up the issue with their forum or demanded a retraction/correction? Who knows maybe Matchless borrowed the design from the same source as you did? Further research for my part to find the source, however I wouldn't be surprized if Matchless didn't borrow from your design.

The bulk of the post is about derivative designs in reference to backward engineering an amp, as you confirmed the Hammond parentage for the Carmen Ghia being only one example. Of course you disclosed the above (and the origin of its name, was the addition from the Volkswagen automobile that antedates your amps by decades?) in a ToneQuest interview from about ten years ago.

http://www.tonequest.com/articles/dr-z.htm

Yes, I do generally research my statements when I have time, the Matchless quote was a slip in critical thinking (questioning a quotation of other's research) and I am guilty as charged. Since the lion' share of my business is in electronics and we are in a production phase with a year end delivery deadline, I would normally have taken the trouble to investigate the statement.

In this you are correct to castigate me on this point. Mea maxima culpa.


Steve


PS Addendum to my original post, Sunn Amps and their UL Connection were direct clones of Dynaco (trivia question, what was the only Amp mfg to have an endorsement agreement, briefly, with Jimi Hendrix? Answer, Sunn Amps until Jimi played through one.)

[renshen1957]

'Fender borrowed Western Electric and RCA circuits'

From the Tone Lizard http://boyercentral.net/ToneLounge/www. ... mework.htm :
'Even the fabled tweed covered Fender Bassman amplifiers into the 1950's still had a little sticker inside the cabinet which read....."Licensed under U.S. patents of American Telephone Company & Telegraph and Western Electric Company, Incorporated, for use only in public address systems, ...systems for distribution from radio broadcast receiving sets or musical instruments...". Take two guesses as to whose vacuum tubes Fender used throughout their early years (and not because they had the tone!). RCA forced you to license a circuit design from them and pay royalties.'

So it wasn't Fender borrowing from RCA but rather RCA enforcing their IP of amplifier circuits. Pete.

Hi Pete,

I cannot say for sure if RCA, A T & T, Westinghouse, et al were enforcing IP. Tube lawsuits were more of an issue prior to WW2, new discoveries such as Farnsworth's Television circuitry or Armstrong's use of FM for TV and the invention of FM Radio did interest RCA, RCA did attempt to steal both through back dated patents (TV), and Armstrong, broke and financially bled to death by patent fights (he was a millionaire by the 1920s) committed Suicide. Fender was a very small fish in a very small ocean. Every home had at least one radio, and many homes would have TVs or were planning to purchase them.

As the utility patents generally have a twenty year life expectancy, all of the designs Fender referenced would have been public domain from the mid-50s onward. Not much sense to keep printing the above, after these had expired.

From what I was able to piece together, Fender's statement was more smoke and mirrors for the competition than for patent infringement. Make them think that the big boys would go after them. Black and White printed label in place of "epoxy gooping" (in reference to H. A. Dumble, applying epoxy to non-critical circuitry).

Fender was small potatoes (and is still compared in dollars and cents to large manufacturers) as electronics firms went to be of concern to RCA, Westinghouse, General Electric, Western Electric. These Companies were Radio (including the newly emerging Hi Fi industry) and Television (more so the latter) companies for supplying Tubes for their in house products, as well as to other manufacturers and the military and for industry, including.

If Fender had run short of RCA 12ay7 or 12AX7 during a production run, wouldn't Leo send someone to the local store to pick up a GE tube. Would RCA check up on them? At this time (as a by product of WW2) if RCA ran short of 12AX7 tubes they would just bulk purchase some from another company and silk screen their logo on to the tube, pop it in a box, and sell it.

Also during this time, Fender Circuitry changed very frequently, which would have required additional negotiation, contracts, etc. Doesn't sound very likely.

Fender switched to Tung Sol 5558 power tubes for the Tweed Bassman, still used of mfgs 6L6b and 6L6GB tubes in other models

I will let a tube/valve historian answer which tubes were used. Guitar Amps ran the tubes to their limits in most cases (and combos were the worst tube environments), and subsequent changes in amp usage from county to clean to rock and roll distortion insured that few original tubes in these amps survive to answer this question definitively. (Aside from the occasional ebay factually untouched closet classics that possibly might have the original tubes, but I really doubt these.)

The very old hands at Fender have long since gone, one would have to ask Fender if they had records of licensing agreements payments from 60 years ago to prove that IP had been paid.

Best Regards,

Steve

[DR.Z]

Dear Dr. Z,

A bit touchy on the subject, aren't we?

I guess I am.


I can understand your being cheesed off a bit about, it.

Yeah I do get my share of dissing, while some other amps companies are untouchable.




I wouldn't exactly say the Hammond Amp was useless, (unless you are referring to guitars) I played through a number of them as an Organist.


Yes there amps are nice, but the 0-35 Reverb amp wasn't there best attempt.




As to the quotation I cited is from TDLP,

I thoght you stated TDPR first, not sure I know either of these sites.



Yes, I do generally research my statements when I have time, the Matchless quote was a slip in critical thinking (questioning a quotation of other's research) and I am guilty as charged. Since the lion' share of my business is in electronics and we are in a production phase with a year end delivery deadline, I would normally have taken the trouble to investigate the statement.

In this you are correct to castigate me on this point. Mea maxima culpa.



Not my intent to castigate, only to correct.
Thanks for the post.

DR.Z

[renshen1957]

Dear Dr. Z,

A bit touchy on the subject, aren't we?

I guess I am.


I can understand your being cheesed off a bit about, it.

Yeah I do get my share of dissing, while some other amps companies are untouchable.




I wouldn't exactly say the Hammond Amp was useless, (unless you are referring to guitars) I played through a number of them as an Organist.


Yes there amps are nice, but the 0-35 Reverb amp wasn't there best attempt.




As to the quotation I cited is from TDLP,

I thoght you stated TDPR first, not sure I know either of these sites.



Yes, I do generally research my statements when I have time, the Matchless quote was a slip in critical thinking (questioning a quotation of other's research) and I am guilty as charged. Since the lion' share of my business is in electronics and we are in a production phase with a year end delivery deadline, I would normally have taken the trouble to investigate the statement.

In this you are correct to castigate me on this point. Mea maxima culpa.



Not my intent to castigate, only to correct.
Thanks for the post.

DR.Z

Hi Dr. Z

Both references were typos on my part (haste does make waste) its correctly www.tdpri.com, I will find the original thread, (this is my 5 minute dinner break), I recall it was dated back in 2009. Most likely you can find it by a google search.

The Hammond circuit isn't their most memorable, but to their credit they did promote the concept of Reverberation as an effect which was an improvement over playing a dead room when architects made church buildings acoustically dead so the Sermon could be better heard through a PA system. An early effort to restore the lost 80% reflected sound.

I wouldn't worry about others taking potshots at you and your receiving your share of dissing. Congratulations, you have arrived. It shows you are doing something right if you are a target for such attention. You made the Big Time. When Ule Behringer at Bugera starts cloning your products, your work will have reached Guitar Amp Valhalla.

As to your work, I actually do hold it in high esteem. I have used your boards as examples of large spacing between small components to reduce parasitic capacitance. And instead of making a copies of a Marshal, Fender, or a Soldano clone (like Mesa and Peavey have done), you have tried to mix and combine different aspects of other amps (some less famous) and took a less popular, less safe approach to building guitar amps. Likewise, you showed an interest in Power tubes other than 6L6GC or EL34.

Your interest in UL OT was particularly daring considering the negative bias (excuse the pun) against UL at the time because of Fender's ill designed product. Of course no one said anything negative about UL the Marshal Major when it was used by R. Blackmore. Or if they did no one could hear it after losing their auditory sense from the volume.

Best Regards,

Steve

[Structo]

Thanks for that ToneQuest link.

I hadn't really ever read much about Dr Z or his amps.

That is a pretty cool background story.

There was a time when I had thoughts about going into medical electronics but the 80's recession changed my mind because I had bills to pay so I used my brawn rather than my brain.

It would be so cool to have famous guitarists using an amp or amps that you have built.

I've heard the Hammond crap before. What does it matter how he started?
He took a resource and changed it to suit his need and marketed it.
Sounds pretty smart to me.

[M Fowler]

Dr Z got tired of fixing those CT scanners at the Cleveland VA Medical Center and started building amps instead.

Mark

[FUCHSAUDIO]

PS Addendum to my original post, Sunn Amps and their UL Connection were direct clones of Dynaco (trivia question, what was the only Amp mfg to have an endorsement agreement, briefly, with Jimi Hendrix? Answer, Sunn Amps until Jimi played through one.)

Actually, Sunn was somewhat "authorized" as they made amps using actual Dynaco PAM-1 preamp modules (modded for guitar) and using the Dynaco MK-II and MK-II power amps (chassis and all) as power supplies and power amps. I'm pretty sure they bought them from Dyna direct.

They later started using Dynaco iron, but within their own chassis (I assume it was cheaper and less awkward looking inside) using many of the same circuits. The Dyna iron (as many of us know) is outstanding. The circuits Dyna used (the 7199 driver) was a textbook RCA circuit they tweaked for their amps, which was used by Ampeg, HH Scott and others for many years.

Honestly, I sympathize/empathize with Dr-Z, as many of the comments usually come from people with limited education about circuits, and simply label something "a clone" or "inspired-by" and they don't know enough technically to make an educated assessment of a circuit to make a comment like that. It goes back to "what constitutes a clone" exactly. If you change one part, modify the supply, add features, change a tube type, etc, how far is it before it's no longer considered a clone ? For that matter: Who sits on the "supreme court of cloning" to say what is what ?!?

My Dad used to say "consider the source". If Les Paul told you he liked how you played, and some blues bozo in a bar told you he didn't, what would matter most ?

I get the most chuckles from the people who are lauded for making the best whatever, only to fix one and realize it's a 5E3 barely tweaked, with a Fender reverb grafted on the front end, built sloppily...wtf ?

I know of at least two manufacturers who didn't just take apart amps, but performed CSI dissections on ODS' in the past (one admited, one caught by a customer in the shop seeing it, talk about embarrassing), and I figure so-what. Plenty of people have serviced my amps (many guys I know here and many just repair shops here and there) who called to compliment what they saw and liked what they heard. If they drew a schematic, so be it.

[Reeltarded]

As time goes by, magic becomes science, science becomes art.

It's all about the solder blob.

[9pins]

I thinks fuchs brushed on an important truth, even if you only spend the time looking ata large number of schematics, you begin to see design trends.
so much so that you begin to see just how prevalent some circuits are. what are you really cloning and are you able to sell it as the the amp you cloned.
It seems there's confusion between circuit design and product branding. If I copied the "box" and the "logo" and even the products tell tale marks
and sold it as the "product", it is a crime, whether or not it uses the same circuit, it would be like a cut rate designer purse or high fashion pair of shoes you bought for a steal.
wasn't there a amp shop in England that copied rare marshals? copying the amp isn't the real issue, its selling the copy as the real thing.

put it in another way, Mc Donalds doesn't care is you make hamburgers...
it does care if you try to sell under a name that can be associated or confused in any way with the brand "Mc Donald's".

Dr. Z, and Fuchs and any other successful brand owners are very gracious to be involved in a public discourse concerning their products in anyway.

[renshen1957]

PS Addendum to my original post, Sunn Amps and their UL Connection were direct clones of Dynaco (trivia question, what was the only Amp mfg to have an endorsement agreement, briefly, with Jimi Hendrix? Answer, Sunn Amps until Jimi played through one.)

Actually, Sunn was somewhat "authorized" as they made amps using actual Dynaco PAM-1 preamp modules (modded for guitar) and using the Dynaco MK-II and MK-II power amps (chassis and all) as power supplies and power amps. I'm pretty sure they bought them from Dyna direct.

Hi,

Dynaco sold Dynakits (for the home builder), The first person to come with stuffing a Dynaco circuit in an amp idea was a keyboard player in a band in Vancouver named Terry Coan, who later owned a radio and TV repair shop. He was good electronics technician building up Dynas and jamming in a little 12AX7 preamp on that small chassis and he had another guy building 1 and 2x15 cabs with JBLs. Some of the amps he had the chassis chrome plated if you wanted to pay for it. Coan made quite a few of these and also built up small portable organs that has a unique sound.

At that time a lot of the Seattle area bands like the Wailers and the Sonics and other Pacific Northwest bands would come up to Vancouver to play on the bill with the local Vancouver bands. Just about every bassist had one of those Dynas.

The Sunn guys borrowed the idea because they were involved with all these Pacific Northwest bands (toured with them) and would have surely heard of the Dyna amps from them.

Eventually, Sunn sold to a couple Pacific Northwest bands.

Sunn Amps' official story has Norm and Conrad Sundholm designing a Bass to play gigs back in the Kingsmen (Louie-Louie) era. This went on until one of the brothers sold out his interest and went into Real Estate.

"Semi-Authorized" sounds like the whole project received the 'blessings,' approval, and knowledge of Dynaco and David Haffler. Do you have the Semi authorized information from someone affiliated with the old Dynaco company or this conjecture?

Mind you this was the earlier Sunn Amps models. As to the later models, that is another subject for another time.

Best Regards,

Steve

[renshen1957]

wasn't there a amp shop in England that copied rare marshals? copying the amp isn't the real issue, its selling the copy as the real thing.

Hi.

Company's name is Music Ground that has been sued for counterfeiting amps, vintage guitars, and even Dumbles to be sold as originals.

A major lawsuit was to be settled last year with a liquidator's involvement The major principles were also had a trip to the courts over receipt of stolen property 1/11.

And Music Ground (less one shop in the U.K.) is still in business, and the website is up.

There is a difference between cloning (what Behringer/Bugera, et al) and Counterfeiting (misrepresentation of copy as original). There are a number of Harpsichords in the 18th century said to be Ruckers (16th century) that weren't, counterfeit violins, etc. Nothing new to the business.

Using a basic design and modifying and adapting is one thing, carbon copy circuitry is another, and Music Ground serial misrepresentation of goods is still another.

Best Regards.

Steve

[TUBEDUDE]

Tone King Metropolitan please.[/b]

[TUBEDUDE]

Tone King Metropolitan please.[/b]

[Gaz]

Tone King Metropolitan please.[/b]

1+

Just to see what that damned "mid-bite" circuit is.



Btw, Conrad Sundolm still makes amps here in OR.

http://www.conradamps.com/About_Conrad.html

He actually posts on the Hoffman forum - "Sundhy"
Such a nice guy - we should get him over here too!