My Microfreak vocoder edition randomly changes filter frequency and/or cutoff. I just opened it a few days ago, and this happens once maybe every 5-10 minutes on average, whether I'm playing the keys or not. I can tell it's happening because of the dramatic change in the filter I hear while playing, and the asterisk that appears after the preset name (if I'm not touching the keyboard and so can't hear the change.) I'm plugged in to a US power outlet. I updated the firmware to the most recent firmware as of about three days ago.
It looks like this problem was happening in March of last year based on these forums, but I don't see many recent reports of it
