AKSA said:
Hugh, the mods are perfectly willing to split off threads if they get off topic (as they did here). I would much rather that you request this, or if you find something to be threadjacking, to report it. Making threats of violence (yes, I know that you're being hyperbolic, not literal) and personal characterizations is out of bounds.Steve Eddy said:
Very good point. We have seen too many cases of those individuals with "credentials" embarrasse themselves.
SY said:
I thought the discussion is right on topic SY. It is about the sonic characteristics of 0 FB amps. No?
Decide for yourself - and do your homework
Chas or any one else doesn't have to and ultimately can't prove anthing to yourselves- it's up to you to explore, build, measure, listen, and determine what you think works for you.
You guys are awfully lucky that people like Charles Hansen, John Curl, Nelson Pass, Hugh Dean, and even Jocko Homo
are willing to share some of their experience and knowledge- recognize it as such, and reconsider your defensiveness and belligerence- after all, they have nothing to prove to you. They have arrived at the point in their lives with their philiosphies of what works based on theorization, hard work, and like Edison, trying and discarding an awful lot of things until the goals they're seeking have been realized.
That Ayre Acoustics is the thriving firm it is with world wide sales is all the "proof" you might need that more than a few folks have found Chas's approach to audio design of compelling worth. If you need any more, check out the media reviews on their products. Or, most radical thought of all, go listen to one.
While Chas and others have been plying their trade for decades, they would never deny you the right to work it all out on your own.
So, build all kinds of designs, evaluate everthing from no loop or interstage feedback to very high GBP designs like Cordell's MOSFET amp with Hawksford style error correction (AES) or whatever! Determine for youself what works; give it ten years or more of your life, then maybe you'll understand why none of these guys has to give you proof of anything, and if they do share some knowledge and hints about what they've learned, you'll probably appreciate it a little more.
Lighten up, guys.
~Jon
Disclaimer:
I've known Chas since he was a physics student at CU in the late 70's; he used to work for me at that time; I do have a pretty good idea about the effort he's put into this stuff and what he's leared. BTW, if you've ever heard of Avalon Acoustics, that's a company Chas started also.
Avalon Acoustics Speakers
Chas or any one else doesn't have to and ultimately can't prove anthing to yourselves- it's up to you to explore, build, measure, listen, and determine what you think works for you.
You guys are awfully lucky that people like Charles Hansen, John Curl, Nelson Pass, Hugh Dean, and even Jocko Homo
are willing to share some of their experience and knowledge- recognize it as such, and reconsider your defensiveness and belligerence- after all, they have nothing to prove to you. They have arrived at the point in their lives with their philiosphies of what works based on theorization, hard work, and like Edison, trying and discarding an awful lot of things until the goals they're seeking have been realized. That Ayre Acoustics is the thriving firm it is with world wide sales is all the "proof" you might need that more than a few folks have found Chas's approach to audio design of compelling worth. If you need any more, check out the media reviews on their products. Or, most radical thought of all, go listen to one.
While Chas and others have been plying their trade for decades, they would never deny you the right to work it all out on your own.
So, build all kinds of designs, evaluate everthing from no loop or interstage feedback to very high GBP designs like Cordell's MOSFET amp with Hawksford style error correction (AES) or whatever! Determine for youself what works; give it ten years or more of your life, then maybe you'll understand why none of these guys has to give you proof of anything, and if they do share some knowledge and hints about what they've learned, you'll probably appreciate it a little more.
Lighten up, guys.
~Jon
Disclaimer:
I've known Chas since he was a physics student at CU in the late 70's; he used to work for me at that time; I do have a pretty good idea about the effort he's put into this stuff and what he's leared. BTW, if you've ever heard of Avalon Acoustics, that's a company Chas started also.
Avalon Acoustics Speakers
Re: Decide for yourself - and do your homework
I for one am very appreciative of the kind of participations we got from all levels of people, from Curl, Pass to "green potatos" that know nothing about audio / eelctronics (I being one of them).
I don't think, however, respect means don't ask questions and take everything wholesale. Take my favorite design Mr. Curl for example. I am sure that he makes mistakes, just like the rest of us. and he believed in things that he will later regrete or find incorrect.
It is as much of a benefit to them as it is to us for them to rethink their own "conventional wisdom". Maybe, just maybe once in a blue moon, we will help them find one of those mistakes.
That's quite probable if you factor in the general intelligence of this crowd.
I wouldn't use commercial success of a product or a firm as a yardstick of a design philosophy or concept. Many companies come and go, from the tulip trade of the dutch to the bubble trade of 2000, we should have learnt that being commecially success, even for a long period of time, doesn't help identify the holder of truth.
I for one am very appreciative of the kind of participations we got from all levels of people, from Curl, Pass to "green potatos" that know nothing about audio / eelctronics (I being one of them).
I don't think, however, respect means don't ask questions and take everything wholesale. Take my favorite design Mr. Curl for example. I am sure that he makes mistakes, just like the rest of us. and he believed in things that he will later regrete or find incorrect.
It is as much of a benefit to them as it is to us for them to rethink their own "conventional wisdom". Maybe, just maybe once in a blue moon, we will help them find one of those mistakes.
That's quite probable if you factor in the general intelligence of this crowd.
JonMarsh said:That Ayre Acoustics is the thriving firm it is with world wide sales is all the "proof" you might need that more than a few folks have found Chas's approach to audio design of compelling worth. If you need any more, check out the media reviews on their products. Or, most radical thought of all, go listen to one.
I wouldn't use commercial success of a product or a firm as a yardstick of a design philosophy or concept. Many companies come and go, from the tulip trade of the dutch to the bubble trade of 2000, we should have learnt that being commecially success, even for a long period of time, doesn't help identify the holder of truth.
My point is that the only truth you'll accept, is that which you've discovered and earned for yourself.
Pass, Dean, Hansen, et. al, don't have the same "truth", but they've all paid their dues and learned a lot of things the only way that ultimately counts. I.E., no easy answers to life on the internet, just a lot of opinions.
Discover your own truth, i.e., design philosphophy.
OTOH, thinking a darlington pair and a CFP pair are equivalent in the use of feedback IS roaringly funny!
~Jon
Pass, Dean, Hansen, et. al, don't have the same "truth", but they've all paid their dues and learned a lot of things the only way that ultimately counts. I.E., no easy answers to life on the internet, just a lot of opinions.
Discover your own truth, i.e., design philosphophy.
OTOH, thinking a darlington pair and a CFP pair are equivalent in the use of feedback IS roaringly funny!
~Jon
JonMarsh said:
we routinely accept truth from others, like textbooks, teachers, newpapers, journals, etc. and the internet. if we had to discovered every bit of truth by ourselves, we couldn't have advanced this far.
Standing on others shoulder is a must.
JonMarsh said:
I wouldn't call design philosphophy a "truth". I just wanted to use as many mosfets in my amp as I can because I like them. it is not about truth but my preference which can be totally different from person to person. and I cannot call others wrong because they don't share my "preference".
JonMarsh said:OTOH, thinking a darlington pair and a CFP pair are equivalent in the use of feedback IS roaringly funny!
~Jon
then educate us - I don't take a particular stand on that.
We can make this place great if and only if we share our "truth" and ideas. Right?
millwood said:
Yes, we can.
But it seems some think what makes a great place is a handful of "gurus" ministering to a flock of unquestioning sycophants.
What I think is roaringly funny is that so far none of these "experts" have been able to make an unambiguous case that the CFP has substantially greater feedback than the Darlington.
se
In terms of current, I see no difference between CFP and darlington, since both topologies have the same current gain [beta1 * beta2] and in both cases there are only the internal current feedback artifacts present on bipolar transistors
Using voltage drive, I see the darlington as one local feedback loop whose output feeds another local feedback loop, and the CFP as a unique feedback loop with two devices inside
I think that CFPs are only useful when driven from a voltage source
Using voltage drive, I see the darlington as one local feedback loop whose output feeds another local feedback loop, and the CFP as a unique feedback loop with two devices inside
I think that CFPs are only useful when driven from a voltage source
I'm real short of time at present, but I'd like to add this.
Any amp with interstage or global feedback sounds different to one without. CFPs sound very different to emitter followers. True story. Build and listen. It surely relates to correcting after the event; loop feedback creates a spray of high order artefacts. Using faster components, 'shorter' topologies and shorter paths will minimize this effect, and global feedback amps can be built which still sound good, though not the same as a feedback-less amplifier.
Steven, Pavel Dudek, and Charles' Hawksford output stages were a revelation to me. They look extremely elegant, and use non-reactive, current driven mechanisms to keep all outputs on. I like it a lot and will surely investigate it more.
Switchless Class AB also can be achieved with single ended push pull. I have done so successfully. However, there is much more H2 and H3 than the Hawksford approach, though there is no global or interstage feedback.
On visitations from luminaries, like Pavel, Terry, NP, JC, Charles, think about it. These guys will only cast their pearls if they are made to feel welcome, and not attacked for holding views which differ from convention, or even text book. Most here are interested in new audio technology; on a forum, these guys are where it comes from. People who attack Nelson in his forum are either misinformed or idiots, and most would not begrudge him due respect. It is difficult to reconcile equality with the unequal contribution he makes daily. Those who are reluctant to respect people who have dedicated a large portion of their lives to an area which for them is a mere interest or hobby are naive fools. Millwood, you raise the spectre of Animal Farm. An absurd and baleful comparison; this is not a totalitarian environment at all, and no-one lords it over any other simply because they know something another does not. Indeed, the status of many of the people here present is often deliberately shrouded in mystery. I conclude from this that this forum is probably that most unusual group - a secret, knowledge-driven democracy. If someone speaks with authority, listen attentively, you might even learn something, and you might, on reply, be able to teach them something too. If it is nonsense, you be the judge. Challenging each comment, particularly in a personal way, sets people on edge and they soon leave.
To be an effective judge, pay your dues, build the damn thing instead of tinkering idly with PSpice, and listen. It's about building, listening, and forming a subjective opinion of your own. The average audiophile is concerned ultimately with how it sounds, and this is one technology where good specs probably mean less than anywhere else. It is not about nursing hidden resentments that so and so might just be looking down his nose at you. That is your problem; not their problem.
Cheers,
Hugh
Any amp with interstage or global feedback sounds different to one without. CFPs sound very different to emitter followers. True story. Build and listen. It surely relates to correcting after the event; loop feedback creates a spray of high order artefacts. Using faster components, 'shorter' topologies and shorter paths will minimize this effect, and global feedback amps can be built which still sound good, though not the same as a feedback-less amplifier.
Steven, Pavel Dudek, and Charles' Hawksford output stages were a revelation to me. They look extremely elegant, and use non-reactive, current driven mechanisms to keep all outputs on. I like it a lot and will surely investigate it more.
Switchless Class AB also can be achieved with single ended push pull. I have done so successfully. However, there is much more H2 and H3 than the Hawksford approach, though there is no global or interstage feedback.
On visitations from luminaries, like Pavel, Terry, NP, JC, Charles, think about it. These guys will only cast their pearls if they are made to feel welcome, and not attacked for holding views which differ from convention, or even text book. Most here are interested in new audio technology; on a forum, these guys are where it comes from. People who attack Nelson in his forum are either misinformed or idiots, and most would not begrudge him due respect. It is difficult to reconcile equality with the unequal contribution he makes daily. Those who are reluctant to respect people who have dedicated a large portion of their lives to an area which for them is a mere interest or hobby are naive fools. Millwood, you raise the spectre of Animal Farm. An absurd and baleful comparison; this is not a totalitarian environment at all, and no-one lords it over any other simply because they know something another does not. Indeed, the status of many of the people here present is often deliberately shrouded in mystery. I conclude from this that this forum is probably that most unusual group - a secret, knowledge-driven democracy. If someone speaks with authority, listen attentively, you might even learn something, and you might, on reply, be able to teach them something too. If it is nonsense, you be the judge. Challenging each comment, particularly in a personal way, sets people on edge and they soon leave.
To be an effective judge, pay your dues, build the damn thing instead of tinkering idly with PSpice, and listen. It's about building, listening, and forming a subjective opinion of your own. The average audiophile is concerned ultimately with how it sounds, and this is one technology where good specs probably mean less than anywhere else. It is not about nursing hidden resentments that so and so might just be looking down his nose at you. That is your problem; not their problem.
Cheers,
Hugh
andy_c said:The moon is made of green cheese. This is a fact.
If anyone thinks I'm wrong, the burden of proof is on you to demonstrate that my statement is false. To do this, you must construct a rocket ship, fly to the moon with it and sample the soil.
Sound reasonable?
I wish Nature or Journal of Finance would take that approach: it would then be soooooooo easy to publish in top journals.
maybe that's why the internet is so attractive to us arm-chair publishers,
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.