Arch Linux

kwhershey

Member

Registered: 2012-08-27

Posts: 16

external dac mpd server

I'm working on setting up an mpd server, running my sound through an external usb dac.
aplay -l lists my device as there.

$ aplay -l

**** List of PLAYBACK Hardware Devices ****
card 0: DAC [USB Audio DAC], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: ALSA [bcm2835 ALSA], device 0: bcm2835 ALSA [bcm2835 ALSA]
  Subdevices: 8/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7

and

aplay -L

null
    Discard all samples (playback) or generate zero samples (capture)
pulse
    PulseAudio Sound Server
sysdefault:CARD=DAC
    USB Audio DAC, USB Audio
    Default Audio Device
front:CARD=DAC,DEV=0
    USB Audio DAC, USB Audio
    Front speakers
surround40:CARD=DAC,DEV=0
    USB Audio DAC, USB Audio
    4.0 Surround output to Front and Rear speakers
surround41:CARD=DAC,DEV=0
    USB Audio DAC, USB Audio
    4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=DAC,DEV=0
    USB Audio DAC, USB Audio
    5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=DAC,DEV=0
    USB Audio DAC, USB Audio
    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=DAC,DEV=0
    USB Audio DAC, USB Audio
    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=DAC,DEV=0
    USB Audio DAC, USB Audio
    IEC958 (S/PDIF) Digital Audio Output
sysdefault:CARD=ALSA
    bcm2835 ALSA, bcm2835 ALSA
    Default Audio Device

However, mpd does cannot seem to find the device.  ncmpcpp says volume: n/a and trying to change it says problems setting volume.
Relevant portion of mpd.conf:

audio_output {
	type		"alsa"
	name		"DAC"
	device		"hw:0,0"	# optional
}

It appears that the soundcard is busy from:

$ cat /proc/asound/DAC/pcm0p/sub0/hw_params

closed

I think this is my problem, but I don't know how to make it open.  Also, is it a problem that
aplay -L
says I have two default audio devices?  I thought I had solved this, but I can't seem to get rid of ALSA being a default.  Here is what I have tried:

#asound.conf

pcm.!default {
   	type hw
	card DAC
	device 0
}

ctl.!default {
	type hw 
	card DAC
	device 0
}

and relevant portion of /usr/share/alsa/alsa.conf (or at least all that I know is relevant).

defaults.ctl.card DAC
defaluts.pcm.card DAC