The last two gigs I've played (saturday and yesterday) my Big Muff (russian) crapped out. The first night it was allright at soundcheck, but failed on me when we played. Same problem yesterday only it didn't work at soundcheck either. The funny thing is that the day after both nights, I've checked it, and it works fine. The bypass sound is fine (it wouldn't be if the battery was flat, or if the cables were damaged, right? (Btw. I checked with other cables as well)) and when I turn it on the led lights up like it should, but there's no sound at all. I've checked the settings and tried replacing cables and as I said it works fine in other situations. What could be the problem?