I own Shure FP22 which is a battery-powered stereo headphone amplifier. It has a feature I like that uses two potentiometers stacked that can be controlled independent of one another on one shaft, on one knob by pulling up said knob. The Shure also has a concentric knob for stereo balance and a switch on one pot, neither of which I need. I’m having some trouble figuring out what to call this dual pot to source one. I don’t want a dual concentric, that has the required two potentiometers but on two seperate controls, knob and ring. I want to control these two pots on one shaft and do so by pulling up and this allows the single knob to disengage one pot and engage the other. Pushing it down returns to the first pot. The ganged pot is close but they turn together, I want to adjust them independently. My goal is to hide a tone control with the volume knob on a vintage guitar that only has a volume knob. Thanks.