I am not trying to program the "low" or "high" speed. I am trying to program the rate at which it changes from "low" to "high" speed. Just like a real motor spinning from slow-to-fast. I don't own an XP80 yet, I'm considering buying one - and this is an important feature. I am NOT interested in external effects processors (might as well just buy a Leslie speaker cabinet and lug it around!).