Hmm... Probably easier to tell by which mixer. However, if this is ANY mixer, then maybe it's simply ANY server you need to start...
bash-2.05a$ whereis esd
esd: /usr/bin/esd /usr/etc/esd.conf /usr/include/esd.h /usr/man/man1/esd.1.gz /usr/share/man/man1/esd.1.gz
That's the ESound server daemon, then you have:
bash-2.05a$ whereis artsd
Which is KDE's sound server.
Although, maybe (and probably actually) you'll have better luck at trying ALSA and getting that going for your card.