Apologies in advance for my ignorance guys, could someone please explain just what these different connections bring to a 5.1 set up. Various Bluray player reviews mention the importance of multi-channel outs when being hooked up to an older receiver ie no HDMI inputs. But would this type of connectivity offer any thing over an optical or digital co-ax, which I currently use. My system is made up of a Denon 1507 AVR, Denon 1930 DVD and Jamo speakers. I am looking to purchase a BDP in the next day or two but wanting to get this issue sorted first.