Initialen











Change color to default
Change color to red
Change color to blue
Change color to green
Change color to yellow
Change color to cyan
Change color to magenta
Change color to orange
Change color to b/w

fuschlberger.net - Howto on Linux, C-Media USB Audio Adapter

Change color to default
Change color to red
Change color to dark red
Change color to blue
Change color to dark blue
Change color to green
Change color to dark green
Change color to yellow
Change color to dark yellow
Change color to cyan
Change color to dark cyan
Change color to magenta
Change color to dark magenta
Change color to magenta
Change color to dark orange
Change color to grey
Change color to b/w

Printme!

Howto setup C-Media USB Audio Adapter and Linux




On this page you will a find a short guide on how to set up this audio adapter under Linux and make it work.
I wrote it because when I searched google I found nothing about this Hardware (and - by the way - it was a bargain on amazon).


All comments, suggestions etc. are welcome. Please contact me at wf-hp@gmx.net.




I needed an external audio adapter for skype because with the soundcard in my computer a microphone didn't work (now after changing to ALSA it does). So I had a look in the 'net and found this hardware really cheap so I thought I would give it a try, although the retailer could not tell me whether it was supported by linux.
Luckily I got it to work :-)


Setting up the USB Audio Adapter

I assume you have the USB-subsystem up and running.
If you are using hotplug, it probably will work out of the box, with usbmgr some customization will be necessary.


Step 1: Kernel-Config

It should work with a vanilla-kernel at least since kernel 2.6.14. The ALSA-USB-module should be part of the kernel, otherwise you would have to patch it.

In addition to the usual ALSA-support, compile (recommended: as a module) usbhid, snd_usb_audio.

The necessary Parameters in the kernel-.config-file are
CONFIG_SOUND=y
CONFIG_SND=y
CONFIG_SND_TIMER=y
CONFIG_SND_PCM=y
CONFIG_SND_HWDEP=m
CONFIG_SND_RAWMIDI=m
CONFIG_SND_SEQUENCER=y
CONFIG_SND_OSSEMUL=y
CONFIG_SND_MIXER_OSS=y
CONFIG_SND_PCM_OSS=y
CONFIG_SND_USB_AUDIO=m

CONFIG_USB_HID=m
CONFIG_USB_HIDINPUT=y


Step 2: Configure USB-Subsystem

If you are using usbmgr: add these lines to /etc/usbmgr/usbmgr.conf:

# C-Media USB Audio Adapter
vendor 0x0d8c product 0x000c module snd-usb-audio

Restart usbmgr.
Now the kernel-modules will be loaded automatically when plugging in the audio adapter.


After plugging the adapter in for the first time use alsamixer -c 1 (if you already have another soundcard configured as card 0) to adjust the volume levels (for playback and don't forget the microphone!) to your needs.


Step 3: Running skype

Update:
Recent versions of skype work with ALSA directly, so there is no reason to play around like described below. Just select in the skype-Options the correct ALSA sound-device for Audio In and Audio Out.

Kept for historical reasons:
I had to play around a lot until a found a solution. Skype 1.2.0.18 obviously
doesn't work with the emulated device /dev/dsp1 (altough play does).
After some research a found some lines that have to be added to ~/.asoundrc or /etc/asound.conf (for system-wide settings) in order to redirect the emulated device /dev/dsp0 to the second ALSA-adapter (which is the USB-adapter).
pcm.dsp0 {
    type plug
    slave.pcm "hw:1,0"
}

Restart ALSA, run aoss skype (with /dev/dsp0) and have fun.




Written 2005-11-25 - last update 2007-02-10


Change color to defaultChange color to redChange color to blueChange color to greenChange color to yellowChange color to cyanChange color to magentaChange color to orangeChange color to b/w

© by wf
webslave (at) fuschlberger.net
Medieninhaber:
Wolfgang Fuschlberger, Salzburg