I had been using a demo unit with no issues from October to January. Mine showed up 2 weeks ago and I have already lost sound output on it a couple of times. The latest was yesterday (when maxed the expression pedal 1) in the middle of a gig , I had to restart, and it came back up about one second before a solo section. Pretty scary. I have also had my unit totally lock up on me numerous times while editing presets. Hope it is not a hardware issue. I am hoping that I am doing something wrong with the expression pedal switch to cause the output to drop out. We will see tonight as I make sure not to hit the expression toe switch at all.