Get the sound card you want to use
aplay -l
Put the Index in the place
pcm.custom
{
type plug
slave
{
pcm "dmix:<SOUND_CARD_INDEX>,0"
}
}
ctl.custom
{
type hw
card Creative
}
pcm.!default pcm.custom
ctl.!default ctl.custom
Copy this into ~/.asoundrc or wherever your alsa sound file is configured
sudo alsactl --no-ucm store