Force SPDIF in ALSA mixer
 

I am trying to get SPDIF output via alsamixer or (even better) gnome-volume-control. Neither will produce SPDIF output, but I've discovered I can do this using aplay -D spdif test.wav. I suspect this is some configuration setting in alsa.conf? However i can't find any documentation and any help would be much appreciated

On the Alsa homepage you might find some specific information regarding the settings for your card