I was discussing in another thread what the ATV outputs via optical. I have my ATV connected via optical to my Denon 3805. With other sources I have this provides a digital input and the receiver decodes the signal and then you have stereo, DD, DTS, etc. My receiver shows a PCM Dig input signal from the ATV. The question I have is the ATV decoding the MP3 and AAC files into stereo? I'm pretty sure my receiver doesn't decode MP3 and I'm positive it doesn't decode AAC files so what's going on? Thanks for any insight you can provide.