first off HI! 
I currently have my pc using realtek on board audio with optical cable connected to my sony str-dg820 receiver using 5.1
I was looking to get the Asus Xonar Essence STX PCI Sound Card
but Im told Im better off using my onboard audio via optical and this wouldnt make any difference using the Asus Xonar Essence STX PCI Sound Card!
using analog through the Asus Xonar Essence STX PCI Sound Card wouldnt make a difference either would it?

I currently have my pc using realtek on board audio with optical cable connected to my sony str-dg820 receiver using 5.1
I was looking to get the Asus Xonar Essence STX PCI Sound Card
but Im told Im better off using my onboard audio via optical and this wouldnt make any difference using the Asus Xonar Essence STX PCI Sound Card!
using analog through the Asus Xonar Essence STX PCI Sound Card wouldnt make a difference either would it?