I've integrated the board into my Raspberry Pi amplifier and adjusted the code to work with the tone control board.

As you can see in the video it is working nicely! Bass treble and volume work properly and respond very quickly. I did not implement a balance control as I don't see any value in that. I've never used that in the past.

The app is still a bit hacked together as the sliders are not working properly :-/ But with some extra work it can probably be fixed rather easily.