My band plays at a regular venue. Great crowd, cool stage and great vibe. I'm a pedals into a clean tube amp guy. Only at this venue, I get way more noise when I switch on my high gain pedal. I know that tube amps and gain pedals hum a bit. But its way more at this venue. I think I have tracked down the culprit. There is a bank of stage lights (colors and stuff), there is also three track-type spots. I went fishing behind the curtains and found the three spots are wired with a sliding dimmer switch. Is this most likely the problem? Or is there more possibilities. I do find that I can turn my guitar away from the amp and lessen the hum to a point, but its a small stage and not a lot of options for repositioning the amp.