I have a question regarding the hook up from the denon 1600 dvd player to the denon 3803.The dvd has a optical out that I use to the 3803 ,for dvd. I was told for a audio cd I need to hook up analog. Do I need to hookup audio channels for all 5.1 speakers to listen to a audio cd? I thoght the digital out would do this like it does on a dvd. thanks for your help.