Ground the chassis of the DAC via the power cord. Ensure that all of your chassis grounds are made to the same point. That is, don't use separate ground wire runs back to your panel. If you have shielded interconnects, attach only one end of the shield to chassis ground, float the other end, in each case float the end at the forward part of the path (i.e. between the preamp and the amp, float the amp end).
static charge
The ground in the female receptacle of a DAC I am auditioning is not conected (by design, to help eliminate the possibility of hum). My listening room has alot of static, probably because of the synthetic carpeting and all my equipment. Whenever I touch any metal (the DAC, the rack, other pieces of equipment) I get a small static shock. However, with the DAC in the system, everything now shuts off for a second or two, and then comes back on. If I remove the DAC I still get the shock, but nothing blinks off. Is there a quick fix for this? (I'm still waiting to hear back from the company). If the DAC didn't sound so good, especially for the price, I wouldn't keep it. But the sound is fantastic. Any suggestions would be appreciated.