Your reply sidesteps my statement, that is, that we can not accurately predict what an outcome will be for a randomly chosen individual listening to reproduced music- will he prefer a tube amp or class d?
Actually it addressed it directly. In due time 'he' will prefer a class D amp as it will sound better, making the tube amp not worthwhile for all its extra hassle. That is what I said earlier. BTW this phenomena is already occurring.
You have painted broad strokes and made claims but not delivered on the proof. You are a manufacturer in a hobbyist forum with a self-interest in a product. I believe it reasonable to hold you to a higher standard. When someone is charging 4 times what a market leading product costs, never mind that it has half the output power, I think it unreasonable to just say "trust me".
This statement is false. Its not me you need to trust. Your trust issue is that you aren't aware that others can hear the same things you do- you don't trust their hearing since you think it can't be the same as yours. In the past you've suggested not in so many words that perception and taste are the same thing. At some point you will be disabused when you drop that story.
First of all, many of these amps, with different opamps, have been tested and while all the results I have seen show that the performance of the amp with these various third party buffer/op amps isn't quite at the level of the stock Purifi buffer and opamp, the measurements do not show any differences which would normally be considered audible in any way. In other words, if there were some issues with the design, one would expect significant differences.
IMO this is a classic example of how the industry in general does not recognize some fundamental properties of the ear brain system. Its as if research of the last 40 years is being ignored. The ear is a lot more sensitive than you think it is and so these differences are more significant than you think. Here's what that's about: the ear uses higher ordered harmonics to sense sound pressure. The ear has about a 130dB range which is pretty crazy. This means that distortion product 100dB down is audible if its unmasked. The ear assigns tonality to all forms of distortion (for example, higher orders are assigned 'harsh and bright'). BTW this latter fact of human hearing has been know for well over 90 years and should not be controversial to anyone but the uneducated.
So what might be considered 'insignificant' if often quite audible. Audiophiles have been dealing with this problem for well over 70 years now; its why we have to take stuff home to hear it for ourselves. This is the inconvenient truth of audio.
I use measurements to screen out products that don't meet my engineering, design/construction, and objective performance standards. From there, those which make the cut get further consideration and audition. I thus use both objective and subjective criteria. I see no contradiction in using both criteria in the purchase decision.
Well you're not alone in that. Everyone I know of does the exact same thing. The contradiction is in the way you've stated your position in the past. Thus I've revised my assessment; you're mistrust isn't others hearing so much as what meets their 'engineering, design/construction, and objective performance standards'.
