I've been wondering quite a bit about this lately, as I've been having a problem with my spdif out from my laptop (realtek). I notice that when I have my WA6 SE fired up and turn up the volume at all I can detect noise that sounds like interference coming from my laptop. When I move my mouse (razer lachesis) I can hear a the higher frequencies of the interference fluctuate directly with the movement of the mouse. The same thing is noticable with the touchpad, but with lower frequencies. Keep in mind that it's not incredibly loud, but it's impossible not to notice. It's impossible to notice any of this interference during music playback, even in quiet passages, but I can't help but think it may be making a difference anyway. What I'm contemplating now, is switching to a dac with usb input, but if that doesn't solve the issue I will be incredibly irritated. Any advice? I'm not trying to hijack the thread, but seeing as the OP has gotten the info he was searching for, I decided not to create a new thread since my question is related.