[Alsa-user] CM8738 spdif I/O mostly distortion

[Thomas <pla...@a2...>]

I recently purchased a CM8738 card.

Alsa 0.9 beta 9 and beta 10 work fine for analog output, but the digital 
I/O does not seem to work in Linux. A small test in Windows showed the 
digital output fully functional.

The only way I have been able to get some audio on the digital output is 
to use the 'IEC958 DAC to Out' option in alsamixer. However the output 
is alway at full level, and sounds extremely distorted.

The IEC958 In Monitor option likewise does monitor the spdif input, but 
likewise the sound is very distorted.

It seems to be a fairly generic card, with a bracket for optical and 
electrical I/O. In case it matters, the vendor is Trust. cat /proc/pci 
shows the chip is a
C-Media Electronics Inc CM8738 (rev 16).

I understand people have this working - so am I doing something wrong, 
or is this a case of a card with 'slightly different hardware'?


Thomas