Martin Colloms argues persuasively in the January 1998
Stereophile 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.