I'm thinking of getting an external DAC, or maybe an integrated amp with a built in DAC, for the ATV. Some of them only have USB inputs (Bel Canto S300ui integrated amp for example). Is there such a thing as a toslink to USB cable adaptor? (am I even correct in calling the ATV's optical out "toslink"?) Alternately, do any of the USB hacks for the ATV enable audio out? Finally, can anyone using an external DAC comment on the difference in sound quality vs RCA out? I have to say, my 320kbps AAC files sound pretty darn good straight out of RCA into my stereo. I wonder just how much better they'd sound through a DAC. Thanks!