No Audio Output on 3.5mm Jack

Question

I have a Raspberry Pi B running Arch ARM. I have setup NFS with my media server. I'm trying to stream music from it and play it with mdp through ncmpcpp (with alsamixer).

I have tried turning up the sound in alsamixer as well as running modprobe snd_bcm2835. I have also tried to play the files with aplay rather than ncmpcpp with no luck.

Kernel:

Linux lithharbor 3.12.7-4-ARCH #1 PREEMPT Mon Jan 20 13:14:34 MST 2014 armv6l GNU/Linux

aplay -L:

null
    Discard all samples (playback) or generate zero samples (capture)
default:CARD=ALSA
    bcm2835 ALSA, bcm2835 ALSA
    Default Audio Device
sysdefault:CARD=ALSA
    bcm2835 ALSA, bcm2835 ALSA
    Default Audio Device

hw_params:

cat /proc/asound/card0/pcm0p/sub0/hw_params
closed

/etc/mpd.conf:

# See: /usr/share/doc/mpd/mpdconf.example

user "mpd"
pid_file "/run/mpd/mpd.pid"
db_file "/var/lib/mpd/mpd.db"
state_file "/var/lib/mpd/mpdstate"
playlist_directory "/var/lib/mpd/playlists"

music_directory "/net/henesys/music"
bind_to_address "127.0.0.1"
mixer_type      "software"

Answer 1

I got this working by running the following command to configure which audio output to use:

amixer cset numid=3 1

The last number is the audio output with 1 being the 3.5 jack, 2 being HDMI and 0 being auto.

Answer 2

The amixer command can list all control interfaces:

$ amixer controls
numid=3,iface=MIXER,name='PCM Playback Route'
numid=2,iface=MIXER,name='PCM Playback Switch'
numid=1,iface=MIXER,name='PCM Playback Volume'
numid=5,iface=PCM,name='IEC958 Playback Con Mask'
numid=4,iface=PCM,name='IEC958 Playback Default'

numid3 is the Playback Route and can be set as described above: 1 = 3.5 jack, 2 = HDMI and 0 = auto

using amixer cset numid=3 1 forces output to the 3.5mm jack.