Could Class D really be that good?

I don't think you are subborn.  You are just checking out all possibilities.  However, ASR themselves say that super low distortion is not required for "perfect sound"  Only a certain measurement of SINAD is needed.  They like lower measurments but they never claim they sound better....because they believe everything that measures below their SINAD value is perfectly transparent.

It is not just the input stage that changes the sound in a Pufifi amp build.....it is the damping of parts and the input board.....the cables, the AC inlet, the output connectors, the quality of parts on the input board. etc. to infinity.  I modify the Sparko regulators and the Sparko pro op amps for better sound.  I modifiy the ouput filter caps on the Purifi boards by removing all 6 on each board and removing the distortion producing steel leads and soldering 6N copper leads using Wonder Solder.  I then test the caps for outside foil and put them all back in so the outside foil is to ground on all the caps.  This makes a noticeable sonic improvement......and no, I bet you cannot measure it.  Look at the reviews of the NAD Purifi amp and my modded Purifi amp on 10 Audio.......he says my amp is way better and even with the mods it is cheaper than the NAD.  This game is infinite......just like our own nature. Eveything makes a difference and most things that make a sonic improvement cannot be measured.

Ric,

I really admire what you do and wish I could learn that skill set someday. It's a pretty good review, and I congratulate you on the impressive 9.5 out of 10 score you received for your mod. I agree that measurements do not imply sound quality, and I believe the listening part of the assessment is greatly lacking in the ASR review. Nevertheless, it is suggested that you send your mods to ASR for his complimentary measurements. Coupling with the excellent listening review you have received, a potential outcome from getting more comprehensive measurements done is that the forum will get to know your mods, your sales will be boosted, and the community will benefit from it. A win-win situation.

@eddnog  I didn’t see any results from anywhere testing the V3 Mono specifically with a 5A power supply versus a 10A, making it even more difficult to say.

Erin just shows the test result today. 'Single' means single amp fed by 48v, 5A psu and 'Double' means double amps fed by 48v, 10A psu.  Having individual 48v, 5A psu feeding to the v3 mono does have 10dB advantage in THD. Interesting. 

@lanx0003 well…guess I should be glad that I went with the dual 48V/5A option, then! Granted, I always believed that in the spirit of actually running separate monoblocs, it would imply powering them with actually separate power supplies as well. It should not be a huge surprise that there are actual benefits to doing it this way. The detriment is always to the wallet, yeah? But in the grand scheme of our beautiful hobby, this specific cost difference isn’t all that huge.

-Ed

@eddnog  Same here. I made a last-minute switch to the separates based on my instinct. I recalled that the overall package deals were identical during the pledge.