Pedal/Damper Input

[Caustic Photon Render Pass]

I have been trying to design an elegant solution for a pedal/damper input that supports both regular "switch" pedals, "half-damper" (potentiometer) pedals, and expression (potentiometer) pedals.

See attached.

I have a Yamaha FC-3, it has a TRS/stereo phone plug and the wiper is connected to the Ring.

I also have a Roland pedal that is a TS/mono phone plug and it is a simple normally closed switch.

When a mono plug is inserted into a stereo jack, the Ring is shorted to the Sleeve. So any reasonable input circuit has to take this into account.

The problem I have is making the input circuit support both mono and stereo plugs without sacrificing too much "dynamic range" into the ADC, and also not sinking too much current from the power supply rail through a switch-pedal when the pedal is up. My design uses a 1k pull-up resistor between the Sleeve and the reference voltage (3.3V in my case). With a 10k pot inside the pedal, this only sacrifices 9% of the dynamic range (1k res vs 10k pot for 11k total resistance from reference to ground). With a 1k pullup to 3.3V, the switch-pedal will draw 3.3*3.3/1000 = 11mW when the pedal is up.

How do the big companies (Yamaha/Roland/Korg) do this?