I have been using the Duet for a few months now. I initially had it hooked up without a DAC and thought it sounded OK. I then tried it with the Cambridge DAC Magic which was a marked improvement. About a month ago I traded the DAC Magic in (long story) for a Cambridge 840C CD player, running the Duet through its digital in, and it sounds great. All of my digital music is AIFF and I have the Duet connected to the 840C with Audio Magic XStream Digital Cable. Though the sound is good and I love the convenience of the Duet and its many cool features, I must say that in my system, the Duet does fall a bit short of the depth and richness that I get from playing CDs through the 840. I still really like it, but if I want to do some serious listening, the CDP gets the nod every time.