The filter cutoff on my Minibrute has gone bad. It seems to be fixed at about 500Hz with a sweep range of a couple of semitones (checked this by boosting resonance). All other settings neutral, double checked for ENV, LFO, Aftertouch, etc, just to be sure. Am I the only one to have this happen? Do I now have to spend money to repair this synth that is not even two years old?