Hello, i want to add some piezo and a preamp on an ABG. It's a Resonator bass (Regal RG-05E) that come with passive Lipstick Pickups (no infos). I dont want to drill any holes on the body, it has 2 knobs (Tone/Volume). I figured out that stacked knob could do the trick, but still not sure on what kind of configuration. (Volume/Volume + Bass/Treble or Volume/Blend + Bass/Treble) I was thinking putting the EMG BTC Control cause im familiar with it on my Electric. And adding this Schatten RG-03 piezo for Resonator Guitar and keeping the stock lipstick pickup (didn't found any better reference for now) Im confortable with soldering i've done some repairs on an passive bass in the past and fixed some Handheld Consoles, but's thats about it with my history with bass electronics. So my questions might seem a bit dumb. How should a wire this ? what kind of stacked pots i should use (250/500) ? and is there anything to check before connecting the two pickups together on the BTC Control ? Am i suppose to ground an ABG resonator ? Thanks.