Class D

he needs extraordinary proof to support his claims

I know you don’t believe them, just look at the Technics SE-R1 at what it does and the press reviews it gets of it sound quality.
Which rids the Class-D bugbear of many that say the uppermids/highs are the problem with Class-D.
And what designers of higher standing than you quote.
Just one of those quotes from Cyril Hammer probably one of the best solid state designers in our lifetime with Soulution Audio amps https://soulution-audio.com/

Cyrill Hammer (Soulution)

"if you want to have your Class-D product performing at the cutting edge it is not possible with todays known switching technologies. In order to come close to the performance of the best linear design we would need high-current semiconductors that provide switching frequencies of several MHz or even GHz."

Now we do have those devices in the GaN, but so far the only one using those 1.5mhz switching speeds is in the Technics SE-R1.
All the rest, including you are not using the GaN technology to it fullest. You started with a clean design slate, you should have utilized the GaN to it fullest, but you state you didn't. maybe you just didn't have the ability to do it like Technics design brains trust team do.

Cyrill Hammer is a good designer but entirely mistaken in his comment you quoted.

When class D amps (Purify) are making distortion that is 120dB down, it is serious cutting edge; lower distortion than the Soulution amps.

Again, you need extraordinary proof to support your extraordinary claims.

I wonder if it would ever be possible to have a class D thread that could be declared a georgehifi-free zone.

@atmasphere  You have the patience of Job... and then some.

Gotta say, the energy and vitality George brings to discussions about Class D makes it seem rather personal.  As if Class D killed his dog, and he is John Wick.

If Class D was even 10% as bad as he makes it out to be it would be a non-issue.  Class D would be dead and none of us would listen to it, and no one would need to bash it. It would be it's own worst enemy, and attract flies and locusts whenever anyone turned a Class D amp on.

But yet, here we are.

If Class D was even 10% as bad as he makes it out to be it would be a non-issue.

You are the rumour spreader, not once have I said Class-D is bad, if fact I’ve praised the Hypex NC500 with linear power supply monoblocks (given the right loading) that I own in my second system. Class-D has yet to reach the same sound quality as good linear amp in the upper mids and highs.

What you need to get right, is that I say Class-D the way it’s used (except for the Techincs SE-R1) has problems that MANY hear in the upper mids/highs, the deaf may not hear it.
And this is a long way being fixed in the Technics SE-R1 by having a 1.5mhz switching frequency/low order output filter instead of 400-600khz as all are today.

And those that are, or going to use the GaN transistor technology have the chance "to use 1.5mhz", but don’t, probably because they don’t have the R&D knowledge skill of Technics behind them to do it.

And btw Cyril Hammer was the first to say this, even before GaN transistors were released to the market. And has more solid state knowledge in his little toe than some "tuber" here saying anything else.

Cyrill Hammer (Soulution)

"if you want to have your Class-D product performing at the cutting edge it is not possible with todays known switching technologies. In order to come close to the performance of the best linear design we would need high-current semiconductors that provide switching frequencies of several MHz or even GHz."
https://soulution-audio.com/series7/soulution-701-mono-amplifier/