[alsa-devel] C-Media CMI8738-LX noise in recording from line in

Lars Schotte lars.schotte at schotteweb.de
Thu Apr 1 03:18:25 CEST 2010

I have this Sweex Sorround sound card PCI and I want to use it for
recording / digitalizing / magnetic and other media types through
line-in. I have to use that card (or another) because the built-in
sound card doesnt work /is broken/.

The soundcard has following chipset - C-Media CMI8738-LX.

So I try to record from the line in input, which works for listening,
so line in input is played good through line out then. I dont know if
there is a passthrought or sth. however, when I record it, using
audacity, or even alsarecord / it doesnt matter / the sound is reported
and also actually is too silent and there is a lot of noise. So with
that noise, this card is for digitalizing useless.

this soundcard has physically no shared connector with the rear, or
bass or whatever. so there are 5 connectors, line in, mic in, front,
rear and cent/sub. each for himself. maybe thats the case, that the old
ones did have shared one and therefore it breaks the recording or
whatever, just a theory. because a few years ago i had an old cmipci
and that one worked fine.

just to be clear, there is sound, so it records, the problem is that
its too silent and there is a lot of noise in it. i write this note
because I saw some reports that suggest that it produces _only_ noise
in recording. thats not the case here.

Lars Schotte @ romy

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