Isn't this just an age old symptom of playing muliple keys IE a chord ? I mean you are in effect playing multiple signals at the same level so the overall level is raised I could well be wrong but i have found this to be the case with many analogue poly synths where as a lot of the digitals i own have some kind of multi key attenuator built in Please keep in mind i know screw all about electronics and could be talking total s**t just going by my previous experience Cheers