Questions re:  GaNfet technology vs other designs.

you are twisting my words to attempt to win an argument. Clearly I said your OTL amplifier cannot be neutral compared to a high damping factor amplifier. You have said nothing that disproves that.

I'm not twisting your words, simply pointing out that without direct experience you simply are not in a position to know the truth of the matter; i.e. you are wrong. Not a judgement or anything, just didn't get the 'facts' right is all (and still abundantly clear you didn't read the article at the link I provided).

The reason the two amps sound similar is the distortion spectra is very similar (although fir entirely different reasons). The reason the class D sounds a bit more transparent is the distortion is quite a bit lower. You have to listen closely for the difference; the easiest way to hear it is that the class D is a bit better at bringing out detail in the rear of the soundstage (distortion obscures detail so this is no surprise). I'm by no means the only one to say this; our customers that have had both amps in front of them say the same thing.

To be clear there are many speakers were this won't be the case! But I didn't stay in business nearly 50 years selling amps to people when I knew they wouldn't work. That leaves a lot of speakers out there on which our OTLs are quite neutral. I refer you to reviews, as there are quite a lot of them...

Does it sound loud. Of course it does, even if the distortion is low,

A lot depends on what is meant by 'low'. In the case of whatever you were thinking of, apparently not low enough. When its a system you of course can't ascribe the 'loudness' being caused by the amps or speakers, but its pretty safe to say that in a proaudio situation where sound pressure is favored over fidelity, its going to sound loud.

I can't help you with not getting the point of my comment about loudness; FWIW a lot of people reading this thread will get it.

 Technics SU-R1000 Integrated Amplifier is GaNFET as is the Gato DIA 400s integrated Amp.

Someone asked about integrated GaNFET's earlier in this thread I think. 

I'm not twisting your words, simply pointing out that without direct experience you simply are not in a position to know the truth of the matter; i.e. you are wrong. Not a judgement or anything, just didn't get the 'facts' right is all (and still abundantly clear you didn't read the article at the link I provided).

I don't need personal experience to know that 4 ohms of output impedance M-U-S-T have a significant impact on the frequency response of any normal speaker with typical impedance swings. There is no talking your way out of that or trying to say it is my inexperience. Nothing you posted in any way negates anything I am saying or in any way supports what you are saying. I am quite familiar with what you referred to in voltage and power paradigm, and your reference to current source.  IF an amplifier follows a power or current source paradigm, its output versus input transfer function into a varying load impedance MUST be different from a pure voltage source transfer function, and it must be different because the output impedance is effectively different, and must be different to support either constant current (infinite) or constant power (variable) versus constant voltage (0). Your OTL amps appear to effectively be high output impedance, not that variable, and you just said your new GaN are hard to measure, which appears to suggest they are 0 (or low).  If anyone is being not clear hear, it is not me.

The reason the two amps sound similar is the distortion spectra is very similar (although fir entirely different reasons).

No, you are claiming this is the case, while just hand waving away the vastly different frequency response that must exist that will greatly exceed any impact of distortion, which you have provided no evidence of audibility beyond hand waving about concepts that most will not discount while claiming that distortion >> 105 db down is audible which is biologically impossible due to masking, impractical and unlikely due to the harmonics already in music, and physically impossible due to limitations in speaker distortion, and the extreme volume levels that would be required.

I can't help you with not getting the point of my comment about loudness; FWIW a lot of people reading this thread will get it.

You can't help anyone with this as you have provided 0 evidence to support your supposition, and have not even showing viability within the limits of biology, practical music, or physical implementation. You have basically ignored all three practical limits and stated something that fails all 3.  You are making the extreme claim. The onus is on you to provide validity or at a bare minimum, even if possible, let alone audible.

Now seeing your posts on other forums, I see this is a pointless discussion. You will keep making unsupported claims, even if they violate what we know about biology, the spectral composition of real music, the fundamental properties of real world speakers, and the limitation of the volume levels that almost anyone listens to music with.