[PlanetCCRMA] Playing Surround Sound with Alsa Drivers

[Miguel Pastor]

I've just installed the Alsa drivers for my Turtle Beach Santacruz card (CS46XX) 
and everything is working fine except that I can not get surround sound
from it. I can see a device surround40 using "amixer -l" command, but I
cannot use the device to produce sound with aplay, even though I can
independently send sound to the front or rear spekers.
Any ideas what can be wrong?

Thanks in advance for any help.