I have an amplifier and speaker system installed in my apartment to which I want to transcode audio ouput from any application on my laptop over my home WLAN. My roommate has an apple airport express, but I can't/refuse to connect through it. Turns out there's no need. I found two useful solutions. One involves transcoding directly from my pc (currently a Lenovo X1 1st generation running Ubuntu 16.04) via UPnP and a few other things. The other involves running a UPnP server on the laptop and connecting remotely from the phone. It took me a somewhat lazy Saturday morning to sort this out, so I'm recording the information here for future reference and sharing.