I am looking at a midi device that will take controller msgs from my pedal board expression pedals and convert them to resistance outputs in the fashion of a potentiometer. I want to use that resistance as a volume controller between my keyboard and amp. I am concerned that the potentiometer will be, by design, linearly scaled, and not as db audio taper. I wonder how this will affect its use. Do normal volume pedals use linear or audio taper pots?