Is an optical cable the best source for sound quality?
It depends on the DVD player, media, your receiver, etc.. as to which is better. Optical, or Digital Coax offer little difference between each other with advantages depending on the specific application. Descrete analog outs can be better or worse depending on what application, with some reference level equipment offering balanced descrete audio outputs. But again it depends on the application and more importantly the cable performance relitive to the equipment, as a poor quality cable can impede quality. But be carful cables are easy to over buy. Make sure you audition all types and models to get your own opinion on what you prefer. In fact the reference user will use all four types based on what they like better.
