Airport Express

Airport Express
Airport Express with Pulse Audio
The Airport Express (AEX) is a network device with an audio output jack that can be connected to speakers or an amplifier. You can stream audio over the network (wired or wirelessly) to (or from) this device.
These capabilities require the newest version 0.9.15 of Pulse Audio and Pulse Audio Volume Control 0.98, as well as pulseaudio-module-raop (for Airport Express). Instead of (or after) installing the default 0.9.14 packages from the Jaunty repositories, obtain them by adding the repositories from this Launchpad site:
deb http://ppa.launchpad.net/themuso/ppa/ubuntu jaunty main
deb-src http://ppa.launchpad.net/themuso/ppa/ubuntu jaunty main
then download the GPG key here
and save it as themuso.gpg.
then install the repository key and update:
sudo apt-key add themuso.gpg
sudo apt-get update
then install:
sudo apt-get install pulseaudio pavucontrol paprefs padevchooser pulseaudio-module-raop
Then configure Pulse Audio:
Menu -> Settings -> PulseAudio Preferences Sound Audio preferences -> Network Access
and check both:
Make discoverable network sound devices available locally
Make discoverable Apple Airtunes devices available locally
Note: Make sure your firewall is not blocking ports 5353, 5000, and 6000.
My AEX is discovered, but I got no sound through it until I selected it as the default sink (output) from the PulseAudio Device Chooser.
K menu -> Multimedia -> PulseAudio Device Chooser -> Manager -> Devices -> Sinks
I then noted the name of my Airport Express device to be raop.Base-Station-e60157.local, so I entered that as the sink:
PulseAudio Device Chooser -> Default sink -> Other -> raop.Base-Station-e60157.local
Now, any devices (or multimedia players) setup to play through PulseAudio will play through the stereo attached to the Airport Express.