Same problem with my helix. Pushing the pedal to 100%, volume goes up to 100% and then fall down 10 approx. 30%. Pushing pedal to 0%, value goes down to 0% and then goes up to approx 30% as well. Was just in service, operates one hour correctly, now same problem. And no, it not depends of log or linear. Helix in this status useless. Tomorrow I will bring back the Helix to service again for a last chance. Very disappointed.