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Re: All of it. You are not listening. nt

Ah but you see this is where you are very wrong. I am listening, a lot, and I am working my way backwards from the listening to the explanation. I am a scientist so I believe in cause and effect. I make observations on sound and then try to develop a hypothesis for why I hear what I hear.

Start with listening, if you are familiar with how music SHOULD sound (unamplified of course) then it is not so difficult to spot gear that keeps good recordings in tact (not just sounding good but sounding realistic). Once you have identified such gear you start looking at measurements to see if they have similar patterns in distortion harmonics, distortion vs. power, distortion vs. frequency, frequency response, etc. etc. I think I have identified general trends that seem to apply to various circuit types and now I am in search of answers as to the cause of such behavior that gives good sound and bad sound.

I know enough electronics and engineering to look at the circuit by its elements and think about how the signal really flows through the circuit rather than a black box approach as soundmind stated "just look at the damping factor!" as if that suddenly explained everything. I am looking at the damping factor and asking a hard question as to why it drops suddenly around 1Khz (give or take) with a simultaneous rise in distortion.

Tom Danley and John Curl are both reasonable and willing to discuss a bit (Tom's I think is probably right on) without Dan's or Soundmind's sneering. Dan's refuge is name calling (at least soundmind refrains from this low form of personal attack), not backing things up with data or hard discussion (soundmind again at least gives a somewhat hard discussion). I ask him for an explanation, give him examples of what I am talking about and wait for an explanation. I have my theories but I am not a trained electrical engineer like Dan. It would be nice to get some real analysis from him. None is forthcoming so what does that mean?

However; it is not enough to say that a high damping factor means low output impedance and that is that because we are dealing with what happens when the signal comes BACK into the amplifier. Then you have to look at the impedance of the elements to find where the signal can flow. My electrical engineer colleague here for sure knows much more than Soundmind about these things and I am beginning to think that Dan never even thought about it seriously. He considers it a major concern and flaw with feedback and when one really thinks about it it certainly seems so.

I wanted to hear a good counter argument from some people, hopefully a lively debate where engineers who think feedback is still a proper solution weigh in with facts not name calling. If the best they can do is that or "look at the damping factor" arguments then I guess it was a mistake to start this thread. The article Dan posted even questions the need for a really low damping factor with regard to frequency response.

What I have found on negative feedback is that most engineers consider it a standard tool and therefore universally good if applied "correctly" . The problem is that anytime an amp measures good and sounds bad then people say, "Oh the feedback wasn't done correctly". Based on Dan's comments, you would swear he is the only engineer making a commercial product who ever used feedback correctly as if he has a deeper understanding of what is behind feedback than all those engineers who have designed with it, used to believe in it, but have now changed their course because experience has showed them amps simply sound better with less and less of it.

Despite what you think, I never troll. Asking hard questions and trolling are two differnt things. I asked a hard question, which Tom Danley explained quite nicely and John Curl also finds important. I was sneered at by the two resisdent pit bulls who think anything other than the orthodox engineering they were taught in school is rubbish. They don't even view tubes as a viable amplification alternative. Tubes are a viable alternative, something that has been shown to my satisfation many times by more than competent engineers.

What they seem to fail to realize is that other, equally well trained engineers, realize that something interesting is going on that conventional amplifier design doesn't readily address.

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