Give this a shot:
Open /etc/modprobe.d/alsa-base with a text editor of your choice and scroll to the end.
append the following lines to the end of it:
Code:
options snd-emu10k1 index=0
options snd-intel8x0 index=1
Please note that I do not know for certain what driver you are loading for your SIS7012 card. I made a presumption that it would be the intel8x0 driver. If that is not correct, then just substitute the appropriate module name where I put "intel8x0".
This should force your audigy to become the "primary" card at every reboot, and the onboard SiS card to become the "secondary". If you want it the other way around, just swap the 1 and the 0.
Hope this helps.