Which DAC as a preamp?


Hi folks...I am looking for opinions regarding DACs to use as a digital pre-amp to drive my red dragon monoblocks. I am considering Audiolab MDAC plus, Musical Fidelity M6s DAC, NAD C-510, or the Audio Alchemy DDP-1.    Any thoughts as to which would be the best pick?
tfats
Personally I havn't heard any of those listed above but a sugestion I would make would be the PS Audio Direct stream DAC. My friend has one and I find it to be very clean with Airy highs and it upsamples to DSD. If I had to buy a dac tomorrow it would certainly be that.
Pairing (synergy) with your Red Dragons will be a major factor. You will need to experiment with different options. Many who try DAC/Pre direct ultimately end up preferring a stand alone DAC and Preamp.

For a DAC with Volume Control, keep Metrum in mind.
+1 David

I like a lean precise detailed neutral DAC and then pair it with a seeet sounding tube preamp. YMMV but I seem to get the best of both worlds - accuracy detail but with warmth and musicality
All valid thoughts folks...thank you.  Somehow...i think that this will be a bit more challenging than I first thought.