20 Year Old Amplifiers compared to 2017

Lets not forget the Carver challenge to Stereophile Magazine (J Gordon Holt) that he could make a $700.00 amplifier (specifically his model 1.0) sound indistinguishable from any high end amp of their choice and he succeeded in doing so.

Well... he was within 30 db if I recall that right.

Amplifier technology reached maturity in the seventies, when output transformers were abandoned in solid state amps. Ever since, well designed amplifiers used within their specifications have exceeded human hearing acuity.

@cheeg, As I pointed out earlier, the statement you quoted isn't correct on several counts. I did not address the output transformer bit, but other than MacIntosh, that really wasn't a thing with solid state amps even in the 1960s. It may be that what he really meant to say was 'coupling' or 'driver' transformer, as a good number of older designs from the 60s and early 70s did employ audio transformers to drive the bases of the output transistors in the design.

As far as 'their specifications have exceeded human hearing acuity', this statement isn't true either for the reasons I stated earlier in this thread.

Amplifier technology reached maturity in the seventies, when output transformers were abandoned in solid state amps. Ever since, well designed amplifiers used within their specifications have exceeded human hearing acuity.

This statement is false.

Humans can easily hear the distortion of most modern transistor amplifiers. The brightness and hardness of solid state is well-known and a topic of endless debate- the brightness and hardness is the direct result of the fact that the human ear/brain system uses higher ordered harmonics to sense sound pressure. The slight amount of distortion is converted by the ear to a tonality. The ear has to be keenly sensitive to these harmonics because of the wide range of human hearing (140 db). So its far more sensitive to them than the lower ordered harmonics.

If anything has changed since the 1970s, its our understanding of human physiology. The audio industry has been a bit slow to respond to that knowledge though, probably because the facts are a bit of an inconvenient truth.