Thanks for replying, Bohan, but I don’t think you’ve read this thread. It’s not about calibration, and I have already purchased Q-wah. The problem isn’t about the range. For example with volume control, whether global or per preset, full heel is off (0%) and full toe is 100%, that part is fine.

The problem is that as the pedal moves from 0-100% it’s not smooth, it “zippers”, in that you can hear it jump between values. The same with wah, or in fact anything you control from the expression pedal. One explanation would be that the pedal’s value isn’t sampled often enough, so that between two samples the value has jumped. I installed software version 5.6.0 recently but it’s still there. The problem is particularly noticable in the lower ranges.

Again, there is nothing wrong with my expression pedal, it’s an Ernie Ball VP Jr 25k, and it works perfectly (i.e. it’s perfectly smooth) with other equipment, like a Line6 M13. Your earlier response of “I just tried it with mine and it works fine” is not how customer support works! The Ernie Ball VP Jr 25k is the pedal recommended by Eventide for the H9 (on this page). Is that what you are using?

Someone said in another post that it used to be smooth, but with a software update a year or two ago it started to have the zipper problem.