If you don't want to switch your kernel (again) nor recompile it yourself, your only option is to locate the driver or kernel module. If you got a driver, install it using the instructions provided with it; if you're looking for a kernel module, here's how it happens:
modprobe -l | less
# Now look for a module filename that sounds
# familiar and might suite your soundcard..
# If/when you find it, remember the modulename
# (filename without the .xx in the end). Press q
modprobe <modulename you just found>
Then simply retry if it works. Modules that you have currently loaded into your kernel can be seen via