I listened to the ifi IDac at the Axpona Show in Chicago last weekend over headphones using the ifi iCan headphone amp and ifi iUSBPower. I will only say this... it was very very good. I am purchasing the dac and a second iUSBPower for my bedroom system. The iDac is very reminiscent of the DP 777 in sound. I know it uses the exact same in-house (AMR) disigned USB board and the Global Master clock system. You should be very happy with the sound from this unit.