Recording Zoom audio and nothing else with OBS and PulseAudio

This won't be a refined blog article, but rather a quick dump of how I got it working just now.

Create a null sink:

pacmd load-module module-null-sink sink_name=ZoomSink

Give it a description (Not sure if it does anything…)

pacmd update-sink-proplist ZoomSink device.description=ZoomSink

Find our new sink's ID:

$ pactl list sources short 7       ZoomSink.monitor        module-null-sink.c      s16le 2ch 44100Hz       RUNNING

If you want to hear Zoom's audio as normal, loop it back to your actual output device.

First, get its ID:

$ pactl list sinks short

Then, loop it back: pacmd load-module module-loopback source=7 sink=0

In Zoom, select ZoomSink as output. In OBS, select ZoomSink as input. Done!