Sorry, but we wouldn't even be having this discussion if great class D amps had been around for ages.
Judging by the measurements I keep seeing, great class D amps still haven't arrived.
That's the first mistake.
Look, I use technology a lot. A LOT!
I believe in it, but I also know the limitations. It is one thing to measure distortion given our most common measures:
TIM and THD+N
They may tell us very little about how this is perceived or how it affects music reproduction to the human ear/brain/pleasure centers. I can critique practically ANY amplifier to death.
And also, take a look at some of the most highly touted amps out there. They aren't exactly stellar spec performers.
My point: Human beings perceive sound differently than pure specmanship. If you want to go "by spec alone" then you really can't make any claims at all. I'd argue that based on the literature, some Class D are excellent amps and no one can hear better.
My point? Your own ears are FAR better judges of quality and pleasure. Find me a measure that compares pleasure to transistor speed and I'll be really interested, but claiming that there's X parameter that Class D amps have to overcome before you admit they are excellent is hard for me to accept.
Do you know what I cannot argue against? People saying "I heard Class D amps by X manufacturer, and I did not like them because they sounded like ..."
That's fine.
But me? I've heard great Class A amps from highly touted makers and I preferred Class D.
And here we are back to my overall thesis:
Buy what you like listening to, specs and other people's opinions be damned. It's your wallet, and your time on earth that is important. No specs, no transistor speed, no class (A/B/D) matters when it comes time to spend your money. Make yourself happy.
What I lack, is a belief that a specific set of technical specs can be made so much better in Class D that they would change everything. Sorry, I like what I have. Show me not the spec but the performance and I may want more.
Please, buy what your ears like.
Best,
E