I've had an A7N8X ASUS motherboard (etc) for awhile now. I'm just now wanting to get an optical SPDIF connection to my stereo. My only digital coax connection is taken by my cable box, but I have one ...

Rightclick speaker icon from system tray -> Rightclick on Realtek Digital Output -> "Test" produces sounds through the speakers connected to the Onkyo. Also, selecting this as the default audio device ...