The M-Audio FastTrack Pro is a 4-in, 4-out external USB1.1 sound-card and uses the alsa Usb-audio module. It can sample and playback with up to 24bit, 96kHz but, due to the insufficient bandwidth of USB1.1, will only work with reduced channel count with anything higher than 16bit, 48 kHz.
There is a Patch by Pavel Polischouk posted on gmane.linux.alsa.devel that makes 24bit sound work with this module by using the snd-usb-audio device_setup parameter. As this wiki does not allow uploads of ".patch" files, I put it in a alsa-feature request. Please try to get the ASCII version of the patch against Kernel 188.8.131.52 from there.
Updated patch to support 2.6.27 Alsa bug ID 0003249. Patch can be downloaded from ALSA bug track. Updated with patch for 2.6.31. Updated patch works as described below.
Suggested entry in
options snd_usb_audio vid=0x763 pid=0x2012 device_setup=0x9 index=5 enable=1
This will put the FastTrack Pro at device number 5 with 24bit mode, max. 48kHz sampling mode, 2 inputs and 4 outputs. According to the patch, the possible values for the device_setup parameter are the sum of the following numbers:
Recording can be done e.g. by using arecord:
arecord -c2 -t raw -fS24_3BE -d5,0 ...
Retrieved from "http://alsa.opensrc.org/M-Audio_FastTrack_Pro"