Negative feedback doesn't always decrease amplifier distortion!
Martin Colloms argues persuasively in the January 1998 <I>Stereophile</I> that negative feedback is not the panacea that amplifier designers believe it to be. His experience of an amplifier (the Cary CAD-805C) and a preamplifier (the Conrad-Johnson ART) that use no negative feedback other than local degeneration, yet have sound quality better than he has previously experienced, convinces him that even when a design's closed-loop distortion appears to be acceptably low, the listener is still aware of an amplifier's very distorted open-loop behavior.