I am having a very odd problem with my 990. I have my DVD player connected via an optical cable. When I listen to a standard redbook cd (2ch), the 990 works fine in its stereo modes. Then if I remove the CD and insert a DD5.1 or DTS DVD (without turning off the 990), I get no audio from the 990 unless I switch inputs (say from Video1 and then back to DVD).

Any ideas?

It sounds like the DVD player isn't interrupting the audio signal output when you are changing discs, causing the 990 to remain in PCM decoding - which will yield nothing because the DD or DTS signal is not compatible with a PCM decoder. Changing inputs forces the 990 to re-acquire the signal, fixing the problem. What player are you using?

I noticed that you are using an Oppo 971. I was testing out some DVD-R's made for work of a series of training sessions, and while I was testing the discs on all of my players I tried to reproduce your problem with all three of my players (Oppo, a Panasonic DVD recorder, and a Yamaha S1500). In each case, swapping a CD out for a DVD worked without needing to switch inputs. You might want to re-visit the settings on the DVD input - are you using upsample or something similar for your CD listening?

Gonk - you nailed it on the head. I was experiencing the problem while I was using my older Panasonic DVD player. Yesterday I hooked up the Oppo and all is now well. Thanks for your help.