Distortion in left channel audio, when using SPDIF I/O port

[rihasant]

When I connect my stereo equipment with my computer, audio plays just fine, but sound coming from the left speaker gets distorted. Notice that the sound coming from right-speaker sounds just fine. I'm using integrated s/pdif-outlet to connect to my stereo.

Motherboard I'm using is ASUS M2N32-SLI Deluxe and it has an integrated s/pdif-outlet, which is controlled by AD1988B HD Audio CODEC. This device (AD198x) has also some audio volume issues with alsa, but that's another bug report.

WORKAROUND:
I also noticed, while I was trying to figure out if this even was a bug, that after I ran "cat /dev/dsp" and "ctrl+c" the sound became undistorted.

SOME INFORMATION:
Release 7.10 (gutsy)
linux-image-2.6.22-14-generic
alsa-base 1.0.14-1ubuntu2

> aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: NVidia [HDA NVidia], device 0: AD198x Analog [AD198x Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: NVidia [HDA NVidia], device 1: AD198x Digital [AD198x Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

[Daniel T Chen (crimsun)]

Please install linux-backports-modules-$(uname -r), reboot, and attempt to reproduce the symptom.

[rihasant (riku.hs)]

I installed the backports-modules and it seems that the bug is fixed by the new 1.0.15 alsa-driver. Thank you for the fast reply, everything is now working as it should be. Although, I had some problems after installing the package. For some reason my alsa-utils crashed and messed up the file in /var/lib/alsa/alsa.state. After this I wasn't able to play PCM through spdif. I found a solution for this problem from the forums: http://ubuntuforums.org/showthread.php?t=445536. The page offered a workaround which fixed the PCM playback...

However, this bug is now closed because the new alsa-driver fixed the distortion problem.
Thanks Daniel T Chan for pointing it out.