Longtime Ubuntu user here. Recently upgraded my Dell XPS 13 7390 from 18.04.3 LTS to 20.04.1 LTS via the GUI upgrade tool. Everything seems to work fine (except for Chromium snap, for all the common reasons), but my main issue is a constant humming/buzzing that I get from the headphone jack. I typically have desktop speakers plugged in, but after upgrade there's a constant, very noticable humming coming from the speakers.

Without the external speakers plugged in, the internal laptop speakers have no hum. Also, if there is a sound event, like the notification sound or adjusting the volume, the hum goes away for a second, but then returns. If I keep the sound settings window open, the hum also disappears.

I tried the fix listed here (https://askubuntu.com/questions/1241...en-the-sound-s), but it didn't work for me.

Any advice? Thank you in advance.