Pedals

Expression pedals: the manual says "Compatible pedals should use a 10 kΩ linear-taper potentiometer, with a 1/4 inch tip-ring- sleeve (stereo) plug with the wiper connected to the tip." So if you use this chart of expression pedals, you're looking for 10k in the "pot value" column and "I" in the "Pedal Type" column. Consistent with that table, Roland EV-5 and Moog EP-3 both seem to work, Yamaha FC7 doesn't.

The included sustain pedal does not support half-damper. The manual says you can replace it with any pedal with a TRS (as opposed to just TS) jack. Unfortunately, though, the Roland DP-10 appears not to work reliably (see Bugs).