To Amir:
Having worked myself through the 22 pages of comments on the subject and acknowledged also the outstanding specs of the Purifi 1ET400A amplifier,
one thing missing to make me a believer would be some "32-tone signal resembling music showing the noise and distortion" test, like for the DACs at decent power.
...actually if s.o. chops my delicate >110dB dynamic range analog signal some 500K times per second and converts level into digital pulse width, one may be suspicious...and "only" 60KHz power bandwidth was something, which (if I remember correct...my old Yamaha A960 had 50KHz, actually never had any concern about it...) was also in question in the 80s until some "safe" >150KHz were achieved by new semiconductor technology...(T+A claims 300KHz power bandwidth for my actual power amp, first version designed in the 90s...)