Hi Martin,

This is very interesting because it brings up another difference between exp pedal inputs on guitar type processors and those on keyboards. I was coming at this more from experience with guitar processors and I should have mentioned that in my post. On guitar processors (and MIDI floor controllers used with them), some degree of programmable expression pedal control is quite common. One reason is that with guitars, exp pedals are often used for wah. A standalone wah pedal has a fairly restricted sweep and exp pedals which mimic that do not complete the full rotation of the pot exactly as you describe. So a start and stop voltage for the pedal has to be programmed. Also guitar exp ports often double as switch ports and can be programmed to expect latching or momentary switches in the expression pedal ports for IA, tap tempo and similar functions. Most guitar processors I have found do expect an exp pedal to use a 3 wire connection and function as voltage divider although some, Line 6 being the most notable, use a 2 wire variable resistor. There is a chart of MIDI floor controllers herehttp://axefxwiki.guitarlogic.org/images/0/09/Floor_controllers_8.jpg that lists the models that have at least expression pedal calibration functions. James.

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