Before the SoundWire Server will run, you must install PulseAudio Volume Controller. This can be done with a single command: sudo apt-get install pavucontrol. The SoundWire Server also requires portaudio, but most likely your system already has libportaudio2 installed. If you issue the command sudo apt-get install libportaudio2, it will either install the app (if it’s missing) or report to you that it is already installed.