I don't know a lot about EE, and this might not be the best place to ask, but I have a really basic question. I'm thinking about cutting an RCA to 3.5mm cable in half and inserting a pot for volume adjustment (it goes from TV to bluetooth transmitter). If that would work then what kind of pot would be best, and could I add another pot for right-channel adjustment? I was thinking that a concentric pot might be able to simplify things (one is better than two). I'd buy a premade cable that does what I want, but I don't think it exists. Any advice would be appreciated.
I'll draw a diagram and update my picture, if needed.