So I registered for the forums just to ask about this: Yesterday at practice I was messing around with my Steel Leather pedal. I also use a Bass Big Muff and a Boss ODB-3. When I put the Steel Leather pedal at the end of the chain, my cab (Ampeg 4x10 of some kind running off of an SWR SM-500), the speaker cones lit up. They weren't flickering, it was a slowly increasing glow, like a lightbulb turning on. It only happened when I was actually playing. I'm sure this can't be good for any of the parts involved, so I'd like a bit of advice: 1) What is going on? 2) Why? 3) What can I do to stop it other than not putting the Steel Leather at the end of the chain, where I think it sounds best.