After doing some research.. I found it exceedingly rare to find any system with a genuine 6.1 audio input. The current one I have, Yamaha HTR-5940, has this.. unfortunately it requires separate 1/8 inch stereo to RCA adapters. So.. I was thinking of just ignoring that particular setup, and going with either: 1. Using the HDMI from the video card / HDMI input > HMDI out > HDMI in to the TV. or 2. Optical 5.1 output from the card. I do know, that some video cards may have issues when having a stereo system in between the card and the TV, such as communication issues, HDCP handshakes etc... so maybe, my best option would be HDMI from the card to the TV, and optical from sound card to stereo?