George,
The ones i heard were built by Veloce audio. They were using a tube input buffer and were running on batteries!! Honestly, I had no idea that they were class D amps. Figured that they were some class A mono blocks that they were running. Definitely worth building. Heck am tempted between springing for a Buffalo 2 and this..might end up going for the buffalo 2 since i want a decent balanced DAC.
The Wyred 4Sound DAC 1 is looking interesting too.