I at least appreciate your commitment to semantics and pedantry.
what would science be without pedantry ?
I guess for you, "solved" or "perfect" represent infinitely perfected performance, and so those terms should actually never be used. A valid point of view. I don't totally disagree but I think it makes discussion a little trickier than it needs to be.
It surely does. "Perfect" is not supposed to be easy. Many say it does not even exist.
The pragmatic point of view is that for any physical electronic audio circuit,
Pragmatic points of view are for engineers. Totally agree with you and with them too. But their products are pragmatic compromises, nothing to do with "perfect".
noise and distortion can never be zero... at least outside of a lab or a giant void in deep space at ~0K. Quantum mechanics makes such a device physically impossible, among other things.
So at that point you have to wonder if there can be a more useful / relevant definition of "perfect". I think the one most people use here is the one I mentioned earlier... an audio device that has no plausibly audible defect when used for its intended purpose.
Granted, a much weaker definition, but one that gives us permission to stop worrying about irrelevant improvements. For example, bumping amp SINAD from 95 to 105 to 115dB will basically never improve the listening experience.
I do think that considering the idea of "perfection" when it comes to speakers is interesting, though. It forces us to wrangle with what a perfect mix / recording might capture, and how one might reproduce that at home. And, thinking along those lines does make it clear that although stereo can be very nice and is very practical, it's far from any concept of "ultimate perfection" we might care to discuss.
Noise indeed cannot be zero (at least that's what our current knowledge of physics says). So perfect is not possible .. and that's just fine.
For HD, a kind of practical zero may be "fully burried under noise". Or it may be something like
this. Or something else. Truth is, we do not even know the definition of (practically) perfect HD.
And that x500 amp is just another engineering compromise, same as any other product anywhere. IIRC, even purifi had some statements about its HD rising with frequency and called that issue a technical compromise. They did not say "amplification was done" and did not go into vacation afterwards.
Long (nagging) story short: serious scientists & engineers should not even talk about "perfect". And consumers should not talk about perfect amps either. The only 'benefit' of such cheerleading/fanboyism are higher prices.
