|"The prob with the A8N SLI Deluxe sound issue is the ASUS site does NOT tell you to use jumpers on the FP_AUDIO block if you are not using a front panel hook-up"|
That's why there's a manual. Chapter 2, page 28.
"ASUSTeK Computer Inc_ -Support- FAQ A7V600-X FAQ How to connect FP_AUDIO on my system.mht"
That explanation *may* be correct, but it's for a completely different motherboard.