When the volume/power potentiometer on my trusty Creative PC speakers broke, I decided to upgrade it instead of just fixing it.
The potentiometer was replaced with an encoder controlling a digital pot. Since everything is now digitally controlled, I added a bluetooth module for remote control and an RGB LED to show the current level.
Original writeup
https://emerythacks.blogspot.com/2013/03/adding-bluetooth-remote-control-to.html
Featured on
https://hackaday.com/2013/03/30/adding-bluetooth-remote-control-to-pc-speakers/