I am new to 5.1 Home Theater and need advice on how to get the best sound from my dvd player once it gets connected to the AVR-3803 that I ordered. I have a Sony DVP-S560D that I hope to upgrade some day but until then I don't know which way is the best to send out the sound. It has RCA connector 5.1 output jacks and digital out via coaxial or optical. I would assume that optical digital output delivers the most pure signal but want to make sure. Are these cables like others in that some are good and some are much better? Thanks!