As promised, this post is the final update on my journey of building high-quality audio solution based on the Raspberry Pi. As I said in my [last post][], I ordered the Terratec Aureon Dual USB sound “card” (around 16 EURs) and a TOSLINK cable. The card arrived in a timely manner and, boy!, this is what I’d call plug ‘n’ play. After connecting it with a USB extension cord to the board¹ the kernel recognized it immediately:

$ lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 0424:9512 Standard Microsystems Corp.
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp.
Bus 001 Device 004: ID 0586:341e ZyXEL Communications Corp. NWD2105 802.11bgn Wireless Adapter [Ralink RT3070]
Bus 001 Device 005: ID 0ccd:0077 TerraTec Electronic GmbH Aureon Dual USB

To my surprise, Poettering’s [brain child][pulse-audio] has not yet arrived in the Raspian distribution, thus sound output is still managed by ALSA. Of course, when I tried listening with [mpd][], music was only output on the crappy on-board jack. So I wasted a lot of time with adapting /etc/asound.conf and whatnot until I realized that I could simply specify a different output and mixer device in /etc/mpd.conf:

audio_output {
    type            "alsa"
    name            "My ALSA Device"
    device          "hw:1,0"        # use the external USB sound card
    format          "44100:16:2"
    mixer_device    "hw:1"          # same here
    mixer_control   "Speaker"       # the mixer for the analog jack
    mixer_index     "0"
}

Now, mpd outputs on the USB sound card and analog volume can be controlled with any mpd client. Compared to the on-board DAC, the Terratec is huge step forward; no hissing, pops and noises at high frequencies. So this is it: my audio setup is complete.