I just did a little experiment, but I have no idea what the results mean. I set the 5000 to PCM and put in "Rise of the Silver Surfer", which is DTS-HD MA 5.1. I chose that track for my audio. On my Onkyo pre/pro, it said "MultiChannel PCM", and listed the frequency sampling at 48kHz. DOH! Now that I think about it, I should have chosen the Dolby Digital track as well and see if it changed anything. Maybe later. However, I then went to bitstream audiophile, and restarted. The Onkyo says DTS-HD MA and lists the frequency sampling at 48kHz once again. FWIW
So the question is, with the 5000 set on PCM, and obviously outputting PCM to the Onkyo, with the audio track chosen as DTS-HD MA, would it output nothing if it was unable to decode onboard??? I definitely had 5.1 output.