Hello. I have VIA C-Media 5.1( CMI8738 ) with my 5.1 on Debian Wheezy.
My 5.1 do not have hardware volume controller and I have some problems
with volume control using system mixer. It does not work correctly
when I use surround51 and when I use ALSA for playing stereo on surround
sound setup. If I do not setup enything and use just my two speakers it
works well.

My .asoundrc for stereo on surround:

pcm.!default {
type route
slave.pcm surround51
slave.channels 6

ttable.0.0 0.5
ttable.1.1 0.5

ttable.0.2 0.5
ttable.1.3 0.5

ttable.0.4 0.25
ttable.1.4 0.25

ttable.0.5 0.25
ttable.1.5 0.25

When this setup enabled my mixer works incorrect, music is too loud
and i can control it only in player(using Benshee). And if I watch
movie using surround51 system mixer controls only two speakers
How I can set up it correctly?