As an owner of the DirectStream DAC Mk2, I must emphasize how wonderful this DAC sounds. It is probably the best sounding DAC under $10K, and may even be preferred by many listeners of much more expensive DACs. It provides clarity and detail, but without any of the digital harshness that affects many DACs. Bass is deep, tight, and real. Soundstage is wide and deep. There is a smoothness and naturalness that eliminates listening fatigue. I have had my Mk2 for only two weeks, and it continues to get even smoother and more "real" sounding as it settles into my system. There is zero hum coming out of my speakers, even with my ear next to the speaker drivers.
Ted Smith, the designer of the DirectStream DAC, acknowledges that there may be some listeners who notice some low-level hum when putting their ear close to the DAC itself. Here are a few of Ted's comments on this issue: "The part that causes the problem is one part. The humming comes from more than one cap that it affects. We did a couple of board turns changing the layout and number and type of caps in this part of the circuit and lowered the hum level. Changing the design overall to totally get rid of the hum would have been counterproductive in overall sound quality." So sound quality is the ultimate goal for the Mk2 DAC, and it succeeds fantastically. Unless you listen to your music with your head next to your gear rack, this low-level hum is a total non-issue. And the Mk2 even has the ability to lift the ground on any input or output that might be contributing to an actual ground loop or other ground-related problem in a particular audio system.