I recently purchased an expression pedal for the line 6 (a source audio dual expression pedal). It works with my m5 but for some reason, the full range of the heel - toe movement is not in sync with the range of whatever parameter I'm controlling.
Example: 1) Heel down, parameter set to 0. Heel up, parameter on reaches about 75% of its range. It will not go further.
2)If I do go further, and set heel up to 100% of range, then heel down position is about 20%. Interestingly, it reaches 0% about 1/3 way up from the heel down position. Essentially, the range oscillates in such a way that "0" isn't totally heel down, but is instead at about 1/3 of the way. Thus, the sweep of the pedal ends up being parabolic instead of linear. Any suggestions? I attached a picture to summarize.