Xonar U7
Asus’ great external usb soundcard works out of the box in linux,
but only with very low sound.
To fix this we have to use alsamixer to increase the gain.
The problem is alsamixer crashes with the message “broken pipe”.
This can be fixed by editing /etc/modprobe.d/alsa-base.conf,
adding the line options snd-usb-audio ignore_ctl_error=1.
Tested with Kubuntu 14.10.
