pcm.dmixer {
     type dmix
        ipc_key 1024
        ipc_key_add_uid false
        ipc_perm 0660
        slave {
                pcm "hw:0,0"
                rate 48000
                format "S32_LE"
                period_time 0
                period_size 1024
                buffer_time 0
                buffer_size 5120
        }
     }

pcm.softvol {
   type softvol
   slave.pcm "dmixer"
      control {
          name "SoftMaster"
          card 0
      }
}

# change default device:
pcm.!default {
     type plug
     slave.pcm "softvol"
}