I found this example of tone circuits and can do some basic audio circuit modifications, ut not an electronics pro, guru, nerd, etc...

https://www.premierguitar.com/articl...ire-a-tone-pot.

Its for listening to lovely wifes "advice" when. I an in one room and she is 40 ft away.... Husband are suppised to hear every word, i am told.

So, anyone know how to add a standard tone control circuit to an off the shelf sound amplifier like this...

The one i have is msa30x "as seen on tv". Treble works great, but no way to filter out the bass frequencies so that bass volume is reduced.

I need a continuous rotating knob instead of apps or 2-3 fixe settings. Does not have to be perfect, can adjust it up or down, etc.

Any leads about this much appreciated.