Are you good at reverse engineering solid state amplifiers when you have the circuit board(s) in hand?
Do you have an interest in reverse engineering some boards that are from a well known high end manufacturer of solid state amplifiers, that I shall not name on the board?
If so, check in here, or send me a private message. If you're able to take a board and map it, your help will be appreciated. All those who participate will get to share the results before anyone else.
For some boards, the ability to map out and understand digital control systems will be an absolute requirement. Other boards are dead simple, as simple as a board stuffed full of large reservoir capacitors, with just a couple of resistors and wires added in.
The amplifier in question is going to be in the 400 watt class, or larger, with fully balanced differential cascoded output circuitry, operating in pure class A at multiple program dependent bias levels. Output device type is OnSemi MJW21195/96 complementary bipolar power transistors, a few dozen per channel.
If you're interested in taking part in a project to reverse engineer a true high end heavyweight amp, PM me about this.
Your reverse engineering efforts should yield accurate schematics that can be followed, and generating comparable circuit board files is a bonus but not necessary.
CJ
Do you have an interest in reverse engineering some boards that are from a well known high end manufacturer of solid state amplifiers, that I shall not name on the board?
If so, check in here, or send me a private message. If you're able to take a board and map it, your help will be appreciated. All those who participate will get to share the results before anyone else.
For some boards, the ability to map out and understand digital control systems will be an absolute requirement. Other boards are dead simple, as simple as a board stuffed full of large reservoir capacitors, with just a couple of resistors and wires added in.
The amplifier in question is going to be in the 400 watt class, or larger, with fully balanced differential cascoded output circuitry, operating in pure class A at multiple program dependent bias levels. Output device type is OnSemi MJW21195/96 complementary bipolar power transistors, a few dozen per channel.
If you're interested in taking part in a project to reverse engineer a true high end heavyweight amp, PM me about this.
Your reverse engineering efforts should yield accurate schematics that can be followed, and generating comparable circuit board files is a bonus but not necessary.
CJ
I like reverse engineering of good amps, and examining where the good sounds coming from.
Sadly, you are far away, and I am on my own project..
Sadly, you are far away, and I am on my own project..
I have done my share of reverse engineering for personal enlightenment. But if the info gained is used for commercial purposes it could be considered theft. E
Why don't you just say what amp you are looking at?
It may have been covered already here on DiyAudio... save you a whole lot of effort.
_-_-bear
It may have been covered already here on DiyAudio... save you a whole lot of effort.
_-_-bear
That's the problem. True high end is subjective. Many high end amp circuits are already available on the internet. Enthusiasm on this project most probably be based on financial reason, not the amp itself.
It takes me only a few hours to reverse engineer circuits, as long as the PCB is not double sided (coz I cannot see the PCB trace under components especially the through-holes under an IC)
Since the discovery of the photo copier reverse engineering is no art. Take a picture of the built PCB write down all the component values. This becomes the overlay.
Remove all components and photocopy (or if you have a modern facility consisting of a PC, scanner and printer) scan top and bottom of the PCB on overhead film. Produce the PCBs and populate them as per the photograph - the Chinese did this for years, why bother with a circuit if you can produce working clones.
Would a schematic make any difference?
On the other hand design your own high end amplifier, it is a lot more satisfying knowing that what you have is your own rather than stealing another man's hard work.
Remove all components and photocopy (or if you have a modern facility consisting of a PC, scanner and printer) scan top and bottom of the PCB on overhead film. Produce the PCBs and populate them as per the photograph - the Chinese did this for years, why bother with a circuit if you can produce working clones.
Would a schematic make any difference?On the other hand design your own high end amplifier, it is a lot more satisfying knowing that what you have is your own rather than stealing another man's hard work.
My guess is that a PCB layout is covered by copyright law. I think that means that, at least in Europe, copying a PCB is unlawful (as would be copying a circuit diagram). Reverse engineering is specifically allowed, but only for the purpose of interfacing to the product without necessarily gaining the manufacture's permission. Product cloning is illegal. In theory the Chinese are now signatories to the international copyright convention (Berne?) but in practice they seem to ignore it.
anything that can be discovered by any level of inspection of a legally purchased product is considered "published" under patent law - it is "prior art"
the accumulation of knowledge thru adoption/adaptation of commercially successful designs/techniques is a major part of technology advancement
your only protection for "intellectual property" are active patents, copyrights, trade secret agreements/license contract terms - although copyright has been extended, twisted to cover software products with new legal limits on "inspecting" copy protection
US patents bar "make, build, use" of the protected inventions
an exact copy of a PCB may be covered under copyright, as would the manufacturer's service manual schematics - even there you are allowed (under copyright) "fair use" copies for your private use - not distribution
but it is perfectly legal to reverse engineer and post/publish your own drawing of the exact circuit schematic or to layout your own version of the PCB - as long as it isn't an exact copy/"mechanical derivation"
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getting something on the expense of others is crap....and moderaters should not allow posts/threads like this.....
inspiration and development is one thing... stealing designs and rights is absolutely not ok....
inspiration and development is one thing... stealing designs and rights is absolutely not ok....
there are acceptable "Clone" projects - forum search: "titles only" returns 475 threads with "clone"
Just because it is leagal does not make it right!
I recently went through a 4 year long, $250k, court battle on this. Fortunately, I was deemed right. E
I recently went through a 4 year long, $250k, court battle on this. Fortunately, I was deemed right. E
I've been keeping an eye on this thread since I approved the first post for that exact reason. Our general principles are to ask - Is the product in production? If so, we are, in general, reluctant to allow the project to proceed. If however, the original is no longer a current model, then, as long as nothing subject to copyright is posted, then we welcome the insights that such a project can give. I for one, contributed towards a project, the Krell KSA50 clone, but stopped public work on another when I found out it was still being manufactured. Classic amps can be a great source of inspiration, both to inspire possible improvements, and allow members to experience something they may not be able to otherwise.
Let me put a few fears to rest. I propose this project only so that I (and others) can learn enough to be able to service these amplifiers and understand their operating principles. I have zero intent of putting anything into production. I have no means by which I could do that in any event.
The manufacturer won't release schematics or service manuals.
They are complex pieces of equipment. I've searched very carefull and found no evidence that they have been subjected to reverse engineering efforts before,
but have found such things as the Krell KMA-160 reverse engineering effort that took place here a few years back. I can state with some certainty that anyone who found that to be a challenge to their skills is probably seriously underqualified to reverse engineer MOST of the amps I'm dealing with. These newer amps have a great deal of digital control circuitry in them and some of the circuit boards are four layers. (At least.)
As for whether or not the product is still in production...it's an older version of a model that is in production today. If that poses a problem, just delete the thread and that'll be that. I'm not out to bring any trouble to anyone. I just want to be able to work on the equipment in question, and without a service guide of some sort, that would be difficult.
The manufacturer won't release schematics or service manuals.
They are complex pieces of equipment. I've searched very carefull and found no evidence that they have been subjected to reverse engineering efforts before,
but have found such things as the Krell KMA-160 reverse engineering effort that took place here a few years back. I can state with some certainty that anyone who found that to be a challenge to their skills is probably seriously underqualified to reverse engineer MOST of the amps I'm dealing with. These newer amps have a great deal of digital control circuitry in them and some of the circuit boards are four layers. (At least.)
As for whether or not the product is still in production...it's an older version of a model that is in production today. If that poses a problem, just delete the thread and that'll be that. I'm not out to bring any trouble to anyone. I just want to be able to work on the equipment in question, and without a service guide of some sort, that would be difficult.
Sinners go to an Audio Heaven
Hi Michael,
copying is a rotten way to get something for nothing. Take yourself for example. Yo and your partners spent several man years to develop your products. That is what the company gives its worth.
After 20 years of hard work and lots of money spent you decide that you have worked hard all your life bringing new things into the market and it is time to retire and pick the fruits of your work, only to find out that your company is worth nothing because every other idiot has cloned and sold your product.
It would seem that people consider that stealing is a lesser sin if it is technology or intellectual property. This category is open for raping the designer, his software or his product, why because we want to teach him a lesson that we are not happy that he makes the money that he does. So in effect the good guy becomes the sinner.
Hi Michael,
copying is a rotten way to get something for nothing. Take yourself for example. Yo and your partners spent several man years to develop your products. That is what the company gives its worth.
After 20 years of hard work and lots of money spent you decide that you have worked hard all your life bringing new things into the market and it is time to retire and pick the fruits of your work, only to find out that your company is worth nothing because every other idiot has cloned and sold your product.
It would seem that people consider that stealing is a lesser sin if it is technology or intellectual property. This category is open for raping the designer, his software or his product, why because we want to teach him a lesson that we are not happy that he makes the money that he does. So in effect the good guy becomes the sinner.
It might have been helpful if the OP had made it clear from the start that his aim was repair, not cloning. The legal situation is unchanged, but many will view the moral situation in a new light. A manufacturer is of course free to keep his secrets to himself, but most reputable ones will be happy to support third party repair.
Secrets may be that the amp has some amazing features which rivals should not see, or some poor circuits which customers should not see!
Secrets may be that the amp has some amazing features which rivals should not see, or some poor circuits which customers should not see!
Hm..., does cmj repair that many of these amps to make it worth his money to retro? Me thinks that if he works on so much of the product that he should have a better relationship with the OEM and, also, as a techie, the ability to retro himself.
Me thinks, but I thunk wrong before. E
Me thinks, but I thunk wrong before. E
He has posted again but will not say what the amp in question is?
Why not?
Is there any amp that is worth anything that has NOT yet been discussed here in DiyAudio to some degree of depth and precision??
Is there some "secret topology" in any production amp?? Nah.
So WHAT IS IT??
_-_-bear
PS. maybe I or someone else ALREADY has the schematic??
PPS. is it perhaps NOT an audio amp?? (thinking servo control amp?)
Why not?
Is there any amp that is worth anything that has NOT yet been discussed here in DiyAudio to some degree of depth and precision??
Is there some "secret topology" in any production amp?? Nah.
So WHAT IS IT??
_-_-bear
PS. maybe I or someone else ALREADY has the schematic??
PPS. is it perhaps NOT an audio amp?? (thinking servo control amp?)
That amp is your own, you may open it, and draw it or ask another for it. Moderator could help us to stay in legal steps. How about some close PCB pictures without removing the components, (Amplifier PCB only for first step) sometimes missing connection in middle 3layers could easily predicted with only from pictures. If the schematic illegal to be post here, we could use private mails.
First, is the model please, because most nowadays amplifiers are very bad, They don't know how to designing amplifiers, just read some funny books and papers, then start to make very cheap or very high component grade, or very expensive prototype. Because loudspeaker getting better and better.
Did you find discussion of this veerryy simple amp? even this simple? (look at attachment)
Did you know what the secret of bootstrap amp? veerrryyy ooold one, and schematic everywhere with many versions.
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