I'm going to need to buy a new DVD player. Current system is five years old. My receiver Sony STR460 has NO optical/digital inputs. I currently run a Sony DVD with discrete 5.1 cabling to the receiver (all RCA). No new DVD players have this option. Can I convert one of the digital outputs the new DVD player to the old receiver, or do I have also buy a new receiver to do 5.1 or 6.1?