Native USB Audio Output Support!

[vortecjr]

It seems to me that these units can support native usb audio output without mpd. Some time back users of mpd made this work so the kernel has the capability. I like mpd, but it would also be nice to just have the unit output via usb in stock form.

The procedure below is for the configuration of another linux based network device posted by John Swenson. I'm wondering if someone here can look at it and tweak the process to work on our units. I would try it, but I don't have a drive in my unit and will not be able to get one for a few days.

Procedure:
BTW this procedure could mess up your unit...
Plug a usb device in the unit first and then boot the unit.

From command line enter
aplay -l

This gives you a list of the audio devices on the unit.
Each device will have a line starting with
card
Example
card 3 USB
The name of the ubs decive in this case was USB

Then this section makes a copy of you original asound.conf is made just in case and to restore the unit. Not sure what sync does.

cd /etc
cp asound.conf asound.conf.orig
sync

Then this section creates a new config file named asound.conf.usb with the following configuration. This will help you filp between original config and usb config later. They use vi as the editor not sure what our editor is.

vi asound.conf.usb

pcm.usbdac {
type hw;
card ;
}
pcm.plugusb {
type plug;
slave.pcm "usbdac";
}
ctl.plugusb {
type hw;
card ;
}

pcm.!default plugusb

Then this replaces the current config with the usb config.

cp asound.conf.usb asound.conf
sync
sync

He says syncs make sure memory buffers get written to disk, but not sure if we need this.

At this point you reboot the unit and the music should now play through the USB device. Since you explicitly told the music to go to the USB device you won't have any sound when the USB device is not connected. To get back to normal you have to SSH back into the unit and type:

cd /etc
cp asound.conf.orig asound.conf
sync
sync
exit

Any feedback would be helpful!