Which DAC as a preamp?

Nuprime DAC-10.  Fully balanced preamp with a DAC included. Designed to work with their own "Class D" amps.  Has worked with W4S, Nord, Mivera, Nuprime and Job amps in my FR system. 

Haven't heard the ones you mentioned, but I had a Bel Canto DAC3VB in my system and in addition to being a great sounding DAC I found its preamp section to be indistinguishable from my Bryston BP6 preamp.  There are a couple 3.5VBs for sale here now, one almost unbelievably cheap.  Read the reviews, and yes the VB version is definitely the one to get.  Best of luck. 

IME, Class D really benefits from a Class A input stage....solid state or valve. Unless you like that lean analytical sound. Many do. Good luck. 

Class D really benefits from a Class A input stage....solid state or valve.

All amps I know ss or tube have Class-A input stages, I've yet to see one with class-A/B

Cheers George

Check out the PSAudio Directstream DAC like others have already recommended here. Very good...