Purifi Class D: Junk?

As Hypex say, "The NC500 poweramp module is devoid of any sonic signature" this is "without the buffer". And it will give the best "sonic transparency/dynamics" if doable, as I do without any compromises, just better sound and a purer signal path from input to output. 
No additional "house sounding" opamp buffers with colourations/distortions in the signal path.  

This is what it says, "Furthermore,the NC500 OEM is an unbuffered amplifier leaving the implementation of an input buffer up to the manufacturer. The NC500 is practically devoid of any sonic signature so this external buffer is a good way of tuning in a “house sound”."

It does not say any of the other things you are implying, and there is no truth that this is true.  We have noted the performance THD+D and IMD is impacted by the output impedance of the buffer when we did testing .... you know on actual test equipment.

What you are hearing is what class d amps do they produce high wattage with low current to save money on energy and expense of manufacture to make more money for the manufacturer and they will not have the required current to dive the proac speakers you have they like a good high current ab type amplifier i am glad you did not spend much money on the class d amp you dodged the bullet with that decision.

@speakermaster  - what do you consider a "good high-current AB type amplifier"?

Class D amps are only current limited by the designer. You can make a super high current class D amp (you just need higher voltage rails and larger fast power supplies and maybe a couple more output transistors.....and great output coil). Class D idles at practically zero current....because its output stage is switching at high speed......does not need to be "on" all the time. What you hear in any class D amp is the designers knowledge...nothing more, nothing less. Tons of high end speakers use class D amps for the bass. The big Von Schweikerts for example.....no loss of dynamics there. There are tons of things in any amp that effect the dynamics.....one bad part and dynamics are history......and this is true for high-current class AB types as well. This is why all class A/B amps sound different.....in the bass/dynamics and otherwise. I do various things in my mods to the VTV Purifi amp that allow for better bass and dynamics and speed. There is no end to tweaking.....no end to knowledge. The Purifi module does 400 watts into 4 ohm...and over 500 watts into 2 ohms (25 amps).......this is enough for most speakers but getting it all out of the module in the most tweaky, dynamic and great sounding way is an art.