I think we have a problem with low voltage at our practice house. I will bring my voltmeter (VOM) and check it next practice. We are plugged into a 20 amp 110 v receptacle with a brick type power conditioner of unknown history. We are running 2 solid state small guitar amps (25 to 50 watts) and a 500 watt Rumble bass head along with a board with 2 500watt amps and a sub amp of about 1000 watts (guessing) I know this is too much for a single 20 amp circuit, but the only other choice we have is to run long extension cords. Any help would be appreciated.