kosst,
I want to see truly perfect measurements under the most grueling load so that when I listen to it I know that what I'm hearing is the sound of perfection
You keep talking about power amps - I'm not.
The core building block that is the "cloning amp" is found in phono stages, line stages, power amps (as the voltage gain) and dacs (as the analog output stage) the power amp will not be "perfect" when driving strange loads. It will successfully drive 90% of speakers. You may have some interaction that is introduced by the amp/speaker coupling/matching.
I have been talking about the amplifier process which is the entire chain of components - not just an amp. This is why I offered to have you listen to the line stage.
Besides I'm sure there are perfectly bad sounding power amps that can produce a KW into 2 ohms or have the perfect square wave at the output - so what?
On the one hand you are saying the specs don't mean anything as far as the sound of the amp (tube amps measure poor but sound great)
Solid state amps can measure incredibly good but can drive you out of the room when you listen.
In other words perfect specs do not mean a perfect amp.
If you examine the core H-CAT amplifier [stage] it has perfect specs and zero distortion. The output stage needed by the power amp to drive the speakers will do its best to maintain the purity that drives it. The power amp has no overall feedback loop (from output to input).
The core process uses tiny amounts of phase correction that can be considered "feedback" because it is a countermeasure but it differs so much from the classic negative feedback because of where it is in the circuit and how it is implemented.