OK so I searched the primer for my answer but can't find it. I bought a used Sony receiver that supports both Dolby Digital and DTS but only the Dolby Digital signal is detected. I get no sound when I choose the DTS soundtrak. I also noticed that the DVD player also decodes Dolby Digital. Does the DVD player also have to support DTS in order for it to send it to the receiver. The DVD player is very old (1997). I'm using the digital coax out. I was also wondering if it possible that the DTS decoder is either not working or was removed. Is this possible?