Hi John,
Welcome back. I for one have always enjoyed Bob's thinking out of the box and his innovative designs. I look forward to hearing about what you are up to.
Cheers,
Bob
Unfortunately, I am not in a position to say much, at the moment, about this design. We hope to have a working example at the Rocky Mountain Festival, but I can't promise at this point. It is out of my hands, so to speak.
We should find something else to 'discuss' on this thread
Hi John,
I plan to be at RMAF.
Cheers,
Bob
Unfortunately, I am not in a position to say much, at the moment, about this design. We hope to have a working example at the Rocky Mountain Festival, but I can't promise at this point. It is out of my hands, so to speak.
We should find something else to 'discuss' on this thread
Hi John
It’s good to see that you are back.
I hope your eyes are ok now.
Could you please tell a bit more about the class d amp.
I’m not interested in details, just some ideas about the topology you are using, is it a self oscillating design? Are you using opamps and class d drivers or is it a discrete design? What kind of output filter, feedback, comparator etc. are you using?
Cheers and all the best.
Stinius
The new amp is not a class D amp. It uses class D power supplies. This amp itself, is linear.
However, the amp uses patented concepts, has a very high effective open loop bandwidth, and is hard to make without serious engineering, for stabilization, since it is relatively complex as a system.
We are thinking of selling pre-potted portions of it to other manufacturers and individuals, but it will take a serious engineer to make it go together properly, and it is more advanced than many amateurs should try.
The fellow who mostly designed it has multiple degrees in physics and engineering and is one of the best designers that I have been privileged to work with, in many years. We don't want to fix anyone else's mistakes, so we can't just offer something, half way.
However, the amp uses patented concepts, has a very high effective open loop bandwidth, and is hard to make without serious engineering, for stabilization, since it is relatively complex as a system.
We are thinking of selling pre-potted portions of it to other manufacturers and individuals, but it will take a serious engineer to make it go together properly, and it is more advanced than many amateurs should try.
The fellow who mostly designed it has multiple degrees in physics and engineering and is one of the best designers that I have been privileged to work with, in many years. We don't want to fix anyone else's mistakes, so we can't just offer something, half way.
Let's get real here ....
Hi John,
Well, the class D power supply is the same concept that Bob Carver used in the Lightstar. The linear amp portion is also the same. Looks like aside from the details, my speculation is in fact, spot on. You can quibble about the details, but the concept is still the same. This is something I am really familiar with.
I think the potted components are entirely silly. If you are worried about being reversed engineered, don't sell any - ever! The potting will only make service impossible and the only people that get hurt are the consumers who supported your circuit ideas. The copy professionals will remove the potting and will successfully copy your circuit. There is zero doubt of that. They can even reverse engineer some ICs these days.
If the circuit is special, most people will not understand the schematic. They sure will not know of any component types or pre-selections to use. The details are still protected in that case. If you are using surface mount components, there is enough trouble trying to look that stuff up to the original type numbers. No basement attempt will be made, and a corporate effort has too much to lose in court.
I think that far too much is made of the secrecy of a circuit. If it's novel, people have to get their head wrapped around it. Now, if it's only a rehash of something done before, you had better pot it. Otherwise it will be seen as it really is. It's telling that Bob Carver didn't pot or hide anything. He had novel circuitry and concepts. If anything, he had reason to protect his intellectual property. He didn't have to.
A question for our members here. Who of you have encountered a potted circuit that was a secret? Now, once the secret was known, how often were the details truly a new concept or circuit arrangement?
I'll answer from my own experience. Every single time the contents of a potted circuit became known, it was just a standard circuit arrangement. I have never seen anything new that was potted. In fact, the only purpose of potting a circuit has been to tie a consumer to the mercy of a parts department.
I have reverse engineered a few potted circuits that were no longer available from time to time. I have been successful in replacing them. John, fear me if you are hiding a normal circuit. Fear me and everyone else like me who won't put up with that stupidity.
-Chris
Hi John,
Well, the class D power supply is the same concept that Bob Carver used in the Lightstar. The linear amp portion is also the same. Looks like aside from the details, my speculation is in fact, spot on. You can quibble about the details, but the concept is still the same. This is something I am really familiar with.
I think the potted components are entirely silly. If you are worried about being reversed engineered, don't sell any - ever! The potting will only make service impossible and the only people that get hurt are the consumers who supported your circuit ideas. The copy professionals will remove the potting and will successfully copy your circuit. There is zero doubt of that. They can even reverse engineer some ICs these days.
If the circuit is special, most people will not understand the schematic. They sure will not know of any component types or pre-selections to use. The details are still protected in that case. If you are using surface mount components, there is enough trouble trying to look that stuff up to the original type numbers. No basement attempt will be made, and a corporate effort has too much to lose in court.
I think that far too much is made of the secrecy of a circuit. If it's novel, people have to get their head wrapped around it. Now, if it's only a rehash of something done before, you had better pot it. Otherwise it will be seen as it really is. It's telling that Bob Carver didn't pot or hide anything. He had novel circuitry and concepts. If anything, he had reason to protect his intellectual property. He didn't have to.
A question for our members here. Who of you have encountered a potted circuit that was a secret? Now, once the secret was known, how often were the details truly a new concept or circuit arrangement?
I'll answer from my own experience. Every single time the contents of a potted circuit became known, it was just a standard circuit arrangement. I have never seen anything new that was potted. In fact, the only purpose of potting a circuit has been to tie a consumer to the mercy of a parts department.
I have reverse engineered a few potted circuits that were no longer available from time to time. I have been successful in replacing them. John, fear me if you are hiding a normal circuit. Fear me and everyone else like me who won't put up with that stupidity.
-Chris
@John:
So, this is a rail tracking amp, or is it something different?
Care to share the patent numbers?
@Chris: You're not alone with your experience with potted circuits. At least the more clever guys additionally grind off the device markings from the semi's before potting to make us work harder
- Klaus
So, this is a rail tracking amp, or is it something different?
Care to share the patent numbers?
@Chris: You're not alone with your experience with potted circuits. At least the more clever guys additionally grind off the device markings from the semi's before potting to make us work harder
- Klaus
Hi Klaus,
True, but that won't stop us! Been there, done that.
Rail tracking is exactly what Carver was all about. I'm dying to hear what makes this different to the Carver concept in the Lightstar and Sunfire.
Only people with something to hide bother potting anything. They are only hiding normal circuit designs and passing them off as something different.
John, I forgot. When did you say you developed the complimentary differential pair? I may have seen it somewhere else.
-Chris
True, but that won't stop us! Been there, done that.
Rail tracking is exactly what Carver was all about. I'm dying to hear what makes this different to the Carver concept in the Lightstar and Sunfire.
Only people with something to hide bother potting anything. They are only hiding normal circuit designs and passing them off as something different.
John, I forgot. When did you say you developed the complimentary differential pair? I may have seen it somewhere else.
-Chris
You're not alone with your experience with potted circuits. At least the more clever guys additionally grind off the device markings from the semi's before potting to make us work harder
Back in 70'th I invented Phaser effect that was not known yet in USSR, because I did not know that Deep Purple on their record used a trick with tape recorders, but I was thinking that it was an electronic effect. I started from rejector filters using LC tanks, the result did not satisfy me. Then I used double T - bridges, and again the effect did not satisfy me. Then I used APFs, got a nice effect I liked, then calculated all details and found that the best effect is when number of APFs is equal to 4, 8, or 16.
So, when first potted copies of Western devices appeared for sale on a black market, out band had it already.
Speaking of potting, it is very useful as protection against aggressive environments.
The copy professionals will remove the potting and will successfully copy your circuit. There is zero doubt of that. They can even reverse engineer some ICs these days.
-Chris
Make that ANY IC. But it needs to be worth the effort.
Regarding potting:
It is very useful in harsh enviroments. Marine electronics is a good example where potting is commonly used. Also industrial environments where nasty corrosive materials are present or where the machine that the electronics is fitted to is commonly washed down with high presssure water ( or worse - the machines are fumigated )
Another valid reason for potting is to equalise the thermal environment. A good example is an ovenised oscillator.
None of my ovenized oscillators are potted. Not a one. I have some examples that were sold as units by themselves, and a few HP instruments that use ovenized oscillators. They are not potted either.
A harsh environment really is a special application, and equalizing thermals is not always going to work, there will be thermal gradients still. Besides, that stuff is terribly expensive. I've only ever potted high voltage multipliers for oscilloscopes after repairing them. Those needed to be potted to cut down on arcing and corona.
So, for audio use, potting is a curse, not a cure. The modules may still fail from heat buildup, solder failure or any other factors. Why do you think they posed a problem in service?
There is no use for potting a circuit in audio reproduction equipment used in consumer homes. The potting can be removed, so protection from copying doesn't exist. There goes the only reason that sounds harmless. They do force a consumer to pay a much higher amount to repair a unit, or it forces them to scrap the equipment and buy a new one. That may be the true reason potting is being considered, not unless a truth is being hidden.
Hi Speedskater,
Hi John,
Well, the tease followed by "I can't tell you any more about it" was better left unsaid. Marketing attempt maybe? I don't know, but what is certain is that the description you gave is very much like the approach taken by Bob Carver and Vic Richardson.
All due respect, but you don't have to be interested in copying anyone to use the same idea. There are only so many ways of doing this, and Bob Carver covered a few all by himself. Doesn't leave much, if any, wiggle room to accomplish the same thing. Especially if economics come into play.
I don't know John. You almost never divulge useful information beyond "here is my new design, but I can't tell you much about it. Real engineers would understand but few here will". Always an insult wrapped up with, "Gee, I'm great". You may not intend to say this, but that is what keeps coming out from your keyboard. Why else would you mention something you can't talk about?
You know what John? When I have knowledge that I can't disclose, I don't talk about it. No teasing, no guessing games, no put-downs. I do comply with any NDAs I have signed, you should too. I don't even "name drop".
-Chris
A harsh environment really is a special application, and equalizing thermals is not always going to work, there will be thermal gradients still. Besides, that stuff is terribly expensive. I've only ever potted high voltage multipliers for oscilloscopes after repairing them. Those needed to be potted to cut down on arcing and corona.
So, for audio use, potting is a curse, not a cure. The modules may still fail from heat buildup, solder failure or any other factors. Why do you think they posed a problem in service?
There is no use for potting a circuit in audio reproduction equipment used in consumer homes. The potting can be removed, so protection from copying doesn't exist. There goes the only reason that sounds harmless. They do force a consumer to pay a much higher amount to repair a unit, or it forces them to scrap the equipment and buy a new one. That may be the true reason potting is being considered, not unless a truth is being hidden.
Exactly. A money game.
Hi Speedskater,
Nope, too complicated and detrimental to the sound quality. The technology to do this is many years old already and is far more simple without an audio quality penalty. Look up a Carver or Hitachi schematic. Carver would be the better example.
Hi John,
Well, the tease followed by "I can't tell you any more about it" was better left unsaid. Marketing attempt maybe? I don't know, but what is certain is that the description you gave is very much like the approach taken by Bob Carver and Vic Richardson.
All due respect, but you don't have to be interested in copying anyone to use the same idea. There are only so many ways of doing this, and Bob Carver covered a few all by himself. Doesn't leave much, if any, wiggle room to accomplish the same thing. Especially if economics come into play.
I don't know John. You almost never divulge useful information beyond "here is my new design, but I can't tell you much about it. Real engineers would understand but few here will". Always an insult wrapped up with, "Gee, I'm great". You may not intend to say this, but that is what keeps coming out from your keyboard. Why else would you mention something you can't talk about?
You know what John? When I have knowledge that I can't disclose, I don't talk about it. No teasing, no guessing games, no put-downs. I do comply with any NDAs I have signed, you should too. I don't even "name drop".
-Chris
Chris, I really don't like your accusations. I TRY to give new info here, because I am excited by it. Unfortunately, my associates tell me to shut up about it, when they found out that I have said anything about this design.
Chris, I am going to say, one more time, you are not an audio design engineer, and many of your associates here are not, either. Please stick to repair, which I am sure you are good at. However, Bob Cordell, Scott Wurcer, and many others have the design experience AND motivation to 'run' with a new concept, even if it is associated with a patent. They work for powerful companies who could get around just about any patent that they wanted to. This is WHY I don't produce patent numbers, even when demanded, on this website. Does this really surprise or disappoint anyone?
Since this Blowtorch thread has existed, how many people have reverse engineered the design JUST with the pictured that Bob Crump took and published many years ago? One, ten, one hundred? We are going to MAKE SURE that that simple path is blocked with this new design, in future. If you want an actual design from my associates or me, please contact us professionally, and pay the rate. My interest here has been to give GENERAL INFORMATION, at significant cost in frustration to me, that I think that all designers should come to know. If that is not appreciated, then I am wasting my time, here.
Chris, I am going to say, one more time, you are not an audio design engineer, and many of your associates here are not, either. Please stick to repair, which I am sure you are good at. However, Bob Cordell, Scott Wurcer, and many others have the design experience AND motivation to 'run' with a new concept, even if it is associated with a patent. They work for powerful companies who could get around just about any patent that they wanted to. This is WHY I don't produce patent numbers, even when demanded, on this website. Does this really surprise or disappoint anyone?
Since this Blowtorch thread has existed, how many people have reverse engineered the design JUST with the pictured that Bob Crump took and published many years ago? One, ten, one hundred? We are going to MAKE SURE that that simple path is blocked with this new design, in future. If you want an actual design from my associates or me, please contact us professionally, and pay the rate. My interest here has been to give GENERAL INFORMATION, at significant cost in frustration to me, that I think that all designers should come to know. If that is not appreciated, then I am wasting my time, here.
Last edited:
Your secrets are safe here. You and your associates obviously believe in the high open loop bandwidth stuff, so go for it. I couldn't find any patents or pending applications, not that I looked very hard, but please don't make any unfouded insinuations.
BTW you need an avatar, maybe SY can fix you up with a good shot of "Mr. Natural".
BTW you need an avatar, maybe SY can fix you up with a good shot of "Mr. Natural".
Last edited:
Scott, it may be news to YOU, but it is not to me, that several Blowtorch 'Semi-Clones' have been made and put up for sale. Without this thread, I doubt that that would have been possible. Now, since we no further make the CTC Blowtorch, perhaps that is OK, but it is not so with my new associates.
When it comes to patents, I have been told to keep quiet by two separate parties. One, because the patent was still pending, The other, because the patent gave too much info about what direction we were going.
I found much interest when I first mentioned these patents. However, they are not MY patents, but others, and I was told, after the fact, to shut up. Is that OK with you, or is everything already invented and distortion mechanisms discovered, so anything new must be just 'marketing'?
These continuous implications of 'imaginary patents' or blatant marketing, is insulting to me. I, like you, don't get paid to contribute to this website, so what could be your interest in it? Blatant marketing? Subliminal advertising for Analog Devices?
When it comes to patents, I have been told to keep quiet by two separate parties. One, because the patent was still pending, The other, because the patent gave too much info about what direction we were going.
I found much interest when I first mentioned these patents. However, they are not MY patents, but others, and I was told, after the fact, to shut up. Is that OK with you, or is everything already invented and distortion mechanisms discovered, so anything new must be just 'marketing'?
These continuous implications of 'imaginary patents' or blatant marketing, is insulting to me. I, like you, don't get paid to contribute to this website, so what could be your interest in it? Blatant marketing? Subliminal advertising for Analog Devices?
- Status
- Not open for further replies.