Hi Andy,
Nice to see you in this thread. There's some good stuff developing here.
I'm not actually sure the answer was "yes". The link Mike provided was back to his critique/denial of MY feedback experiment rather than a build of his own.
It has been cited by several others here that the application of increasing amount of feedback has been observed to sap pleasurable qualities from the sound. I was wondering whether Mike had a real circuit which does not show this effect - that would be interesting. But if not, it doesn't matter.
Out of curiosity, have you observed any related effect in psu performance?
BAM
Nice to see you in this thread. There's some good stuff developing here.
I'm not actually sure the answer was "yes". The link Mike provided was back to his critique/denial of MY feedback experiment rather than a build of his own.
It has been cited by several others here that the application of increasing amount of feedback has been observed to sap pleasurable qualities from the sound. I was wondering whether Mike had a real circuit which does not show this effect - that would be interesting. But if not, it doesn't matter.
Out of curiosity, have you observed any related effect in psu performance?
BAM
Re: Re: Four wasted posts...
Well, I saw that you like referencing to other posts, so I believe you get this:
http://www.diyaudio.com/forums/showthread.php?postid=488290#post488290
Post No. 165 of this thread.......
mikeks said:
Well, I saw that you like referencing to other posts, so I believe you get this:
http://www.diyaudio.com/forums/showthread.php?postid=488290#post488290
Post No. 165 of this thread.......
Yes, it makes a nasty waveshape. The thing is I think it unlikely that an amp would produce such a shape because the zero crossings are not equi-spaced. This would imply some hysteresis at the output. Unusual. Could be.
What circuit mechanism do you think might cause the FM modulation which you propose?
mikeks said:
????????????????? I see no answer..................
I'll give up
No would be fine as well
traderbam,
This thread does have a lot of promise, as you say, so I'll try an resist further noise level rises, despite the excrutiating provocation
Similar effects have been noted in power supplies, as witnessed by the many threads here that have discussed open-loop followers in comparison with feedback circuits, in numerous applications.
Me, I'll stick to trying to make the benefits of feedback work, although I'm open minded enough to accept there may well be applications where the practical limitations of a particular circuit application would make open-loop a better option
Andy.
traderbam,
This thread does have a lot of promise, as you say, so I'll try an resist further noise level rises, despite the excrutiating provocation
Similar effects have been noted in power supplies, as witnessed by the many threads here that have discussed open-loop followers in comparison with feedback circuits, in numerous applications.
Me, I'll stick to trying to make the benefits of feedback work, although I'm open minded enough to accept there may well be applications where the practical limitations of a particular circuit application would make open-loop a better option
Andy.
It's hard Jan to answer Mike's question, without giving the full answer, since part of the purpose of this thread is to test the normal assumptions. Secondly the reaction I get helps me assess who is worth listening to here and who isn't.
Mike didn't pass the test - yet
Think about the input signals and circumstances where a feedback amplifier may not be such a good choice, in a practical application when real devices and other limitations (like commercial ones) rear their ugly head.
Andy.
Could we not try to stick to the subject here? It's quite a PITA to wade through hundreds of pages of crap talk to get up to speed on a matter that may have been covered in the past. Just IM-not-so-HO
The only feedback/no feedback test here that to me seems to have been performed in a somewhat "controlled fashion" is the one performed by Pavel (PMA). With quite interesting results!
I try to keep my eyes open. Sure there are issues with feedback systems, like there are with NFB systems too. The way I tried to look at things a few pages ago was this:
Suppose you go with a NFB circuit. Correct me if I am wrong but unless you bring this guy
along that pretty much means that PSSR is going to be much worse than the same circuit but with GFB.
So, to overcome this problem you use a stable regulated PSU. That simply means that you have moved the feedback loop from the amp to the PSU. I can not see why this would be beneficial compared to the other way round. Or GFB in both amp and PSU...
Sure if you can get along without FB in both the amp and the supply it's a different story. But - well has anyone done this with good results?
Check out the green hair on the drummer!
/Magnus
The only feedback/no feedback test here that to me seems to have been performed in a somewhat "controlled fashion" is the one performed by Pavel (PMA).
With quite interesting results!I try to keep my eyes open. Sure there are issues with feedback systems, like there are with NFB systems too. The way I tried to look at things a few pages ago was this:
Suppose you go with a NFB circuit. Correct me if I am wrong but unless you bring this guy
along that pretty much means that PSSR is going to be much worse than the same circuit but with GFB.So, to overcome this problem you use a stable regulated PSU. That simply means that you have moved the feedback loop from the amp to the PSU. I can not see why this would be beneficial compared to the other way round.
Or GFB in both amp and PSU...Sure if you can get along without FB in both the amp and the supply it's a different story. But - well has anyone done this with good results?
Check out the green hair on the drummer!
An externally hosted image should be here but it was not working when we last tested it.
/Magnus
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