This thread begins with rather odd terminology, i.e., "Seems of late, to be a real push by a select few people", when what is being questioned is long-established in audio technology. Amplification adds voltage to make the weak incoming voltage strong enough to drive speakers at loud levels. If this is done with audibly level frequency response and inaudibly low noise and distortion(easily done these days in even units of modest cost), the job's been done and nothing more is possible. The editor of the Audio Critic summarized this nicely here in
"Electronic Signal Paths Do Not Have a Personality!" .
Of course contrary opinions abound, but when put to the only type of tests which can be taken seriously when scientific accuracy is essential, i.e., carefully controlled double-blind listening tests, no support for them is found. The classic Stereo Review blind listening tests showed that differences described in some rather flowery detail before the blind sessions began disappeared when the brand labels and price tags did(including the comparison of the $220 Pioneer receiver with the $12,000 pair of tube amplifiers). Although in the past "audiophiles" expressed some interest in participating in such tests, now their general level of enthusiasm is about the same as a vampire has for sunlight.
A great thing about the current audio scene is the availability of receivers for a few hundred dollars which perform the basic amplification function with audible transparency. Amplifiers certainly don't measure identically with instruments far more sensitive than our ears, but that isn't the point. As has been pointed out, we listen with ears and brains, not a microphone and electronic analysers, and we're limited in what we can in reality hear.
