12-13-11: Atmasphere
Yes, excessive loop feedback has been a problem in the past! I concur with the THD wars, but amps built for low TIM back in the early 80s or thereabouts definitely got a bad reputation.
Well, audio is certainly a balancing act and if you pursue one spec at the expense of others the overall sound will suffer. Still, taking TIM into account (a balanced approach) probably had a lot to do with why there were more good-sounding SS amps from the '80s than from the '70s.
Another guy who was very hip to this early on was Bob Carver. It probably helps that he's a physicist and not an electrical engineer. He had few preconceived notions and had his own way of tracking down and solving problems. I was just re-reading Absolute Sound's article about 10 most influential amps, and in its writeup of the Phase Linear 700, it mentions that Carver had noticed that tube amps were capable of far wider voltage swings than typical SS amps, so he designed the Phase 700 to make bigger swings like the tube amps. Excessive negative feedback narrows these voltage swings. That may be why Carver never joined the THD wars; his Phase Linear and Carver amps typically claimed .5% THD while his competition was trying to get below .1%.
