I just got the HD 400 for some road gigs after briefly trying a 500 last year. I'm setting up patches but I'm having trouble with the expression pedal. When I use the wah setting it only goes from 0 to 12%, barely a growl. On the volume setting it cuts the sound completely when I rock the pedal just a bit from the toe. I went through Edit but could only raise the minimum volume of the volume pedal to where it couldn't cut the sound at all. I can set the wah wherever I want but as soon as I use the pedal it jumps back down to 0 to 12% Is my pedal faulty or is there some system calibration I can do to make it more responsive?