Which of the two DACs is being used if you use the coaxial i.e. SPDIF out of your DAC (DAC1) to connect to the SPDIF/coax input of your 5.1 A/V receiver, which has its own DAC (DAC2), and then connect your headphone to the receiver? Are you hearing DAC1 or DAC2?
Additional information, the signal from my DAC to the receiver is clearly digital and not analogue. I say that because my receiver can tell you the number of channels (2, 5.1, 7.1 etc.) and bitz/khz (e.g. 24 bitz 96 khz) for any signal it receives via HDMI or coaxial in, but it can't give you that information if it receives an analogue signal (via the L/R RCA inputs for CD player, for example). With the coaxial out of my DAC going into the coaxial in of the receiver, it provides that information, and if I change that setting in my computer via windows (e.g. change it from 24 bits 96 khz to 16 bits 44 khz) the receiver's display reflects that change.
So if my DAC is putting out a digital sort of signal into the receiver, and my receiver has its own DAC to process digital signals, whose DAC am I hearing? The source DAC or my receiver's DAC? I can't completely tell a difference by ear (there might be a slight difference but it's too close to be sure).
Edited by ag8908 - 3/27/14 at 12:47pm