I have the HD-A2. I had to buy a new receiver because my old Sony without DTS could only interpret the audio over SPDIF as Prologic. I got the Sony STR-DG1000 with HDMI audio decoding and the receiver reports Multi-Channel PCM with 5.1 channels working. HDMI=Auto on the A2. I haven't played around with it enough to know if any other HDMI setting works or sounds better. My Receiver can't map an optical input to the HDMI port so I can't report on SPDIF audio.