I bought one of these guitars today and only briefly got chance to try it, but I couldn't figure out the controls at all. Could anyone please link me to a manual, or explain the different jacks, pots and switches etc? The pot closest to me seems to sweep between having sound at 0, no sound in the middle of the sweep, and then sound again (or something like that). Does that seem right? I assume the piezo needs a battery so I'll be changing that out first thing.