I have a Onkyo DTS reciever TX-777 and connected the 563A optical out to the TX777 optical in. I configured the reciever to use the optical input and set it to auto detect for DTS or DD. On the 563A I selected DTS, digital out on and 5.1. Put in a few different DVDs that have DTS and Digital Dolby and selected DTS from the menu on the movie. I also tried selecting DD as well. Some times I might get some music out of the L & R fronts but no center, surround or sub. The reciever never sees DTS or DD (the reciever is set to auto detect these formats and will set itself that mode and display the mode.) If I take the same optical cable off the 563A and put it on the output of my satellite reciever the onkyo detects digital dolby so I know the cable and onkyo are working. I also tried the digital coax out of the 563A and well with the same results. I've changing the audio setting on the 563A a number of different ways and could never get the onkyo to see DTS or digital dolby from the 563A digital outputs. The multichannel outputs of the 563A work correctly, but I want to see if the reciever will decode DD or DTS better than the 563A. Either I'm missing something in the configuration or the unit is defective.