Coax is better except (a) as pointed out above very long runs and (b) if the digital source has rf contamination or grounding problems as can be the case with Digital Satillite music. I subscribe to the 100+ channel DMX service and actuallly convert the coax to optical using a Theta Linque to establish an optical gap from all the rf junk that gets through the coax. I use completely seperate AC for it as well.
