I’ve been experiencing this problem and it seems to relate (at least partly) to the mix control.
For example on preset 1 ambient delay if you turn the program mix down as you approach 50 the level increases dramatically and then as you go down to zero it returns to unity. I understand that the designer has an issue as the mix changes the levels need to be managed, but either they have got the algorithm for volume/mix wrong or it is interacting with the volume/mix of each individual preset in the program in a negative way.
The problem is so bad for me that I get a little distortion on the digital delay at times.
