Not sure if there's anything to be done but the Feedback pot needs re-calibration.
With the knob fully counter-clockwise, TonePrint reads 72%. As I rotate clockwise, the reading increases and hits 100% somewhere around the 11 o'clock position. By 12 o'clock (straight up) it shoots down to 0%. At 3 o'clock it's 13%. Fully clockwise is 38%.
My first thought was a weird mapping but the graph on the Mapping tab shows, left to right, 0, 25, 50, 75, 100.
I bought it used or I'd just return it. Any help?