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Negative feedback Amp=more faithful reproduction?

Negative feedback (NFB) vs zero negative feedback (ZNFB). There seems to be unsubstantiated contention that ZNFB amps sound more realistic. I know this is an age old debate favoring the ZNFB design, but I think most audiophiles have never bothered to look into this matter and believe the advertisements and proponents of zero NFB design. I have been in that camp until recently. My own experience and research into articles on this matter leads to me believe NFB is needed for faithful reproduction of music. I'm not saying NFB design is more "musical", which is a highly subjective term and usually means more euphonic or colored. I've posted a similar question awhile back, but I was hoping we can have a more evidence based discussion on this matter. Perhaps, we need clarification of descriptive terms we use to describe sound. My contention is, in general, NFB designs produces a more accurate or faithful reproduction of music than ZNFB designs. Here is a very good article on feedback and distortion:

http://sound.westhost.com/articles/distortion+fb.htm
dracule1

Showing 2 responses by lloydc

lloydc's avatar
lloydc
737 posts
 
it's adjustable on my amp (Mesa Baron,) so it is easy to hear the differences. I have ears, so I do not really care about the technical rationale. Some music sounds better with a little NFB (primarily studio produced rock), but most music sounds better without any NFB, at least with my system. In general, the sound is a bit less "alive" with NFB, but if a record is made with lots of compression, that hardly matters, and other factors come into play.
lloydc's avatar
lloydc
737 posts
 
NFB is a subtractive process, although as proved by GE long ago, it increases the perceived odd order harmonic distortion. NFB removes some of the signal, and not in real time, either,due to propagation delay within the amp. Although I prefer to trust my ears, and could not care less about the theories involved, theory does match what I hear: with NFB it sounds less "alive". Deadened. Something essential has been deleted from the signal along with the improvement in distortion specs. There does sound like slightly less distortion, but the baby is thrown out with the bathwater. I personally think those who cite the "improved" specs from NFB are missing the point, but to each his own. Not so different from those who prefer SS over tubes, who often cite the "less distortion" specs. No, I don't enjoy listening to distortion, just unwilling to sacrifice aural immediacy to lower it.
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