Q: We have a live venue where we have a lot of noise problems with single-coil pickup guitars. If the guitarist turns 90 degrees left or right, the noise almost disappears. We have tried running a battery-powered amp with guitar to isolate it from the building's electrical systems. The noise is reduced but does not disappear completely. Any advice?

A: Unfortunately, it sounds like you have the classic single-coil guitar pickup problem: noise gets picked up.

The problem probably isn't in your electrical systems. The guitar is probably picking up airborne noise called RF (radio frequency) or EMI (electro-magnetic interference). The only real solution is to change the guitar pickups to hum-canceling pickups (humbuckers or an active pickup, such as an EMG) or to shield the guitar electronics with copper foil or shielding paint.

The source is likely a nearby power transformer, power line, radio station, or some other source. It could also be something in your building or possibly your lighting system.

One other thing you can try is adding a noise reduction processor to the guitar signal path, between the guitar and the amp. Try a Rocktron Guitar Silencer or the Electro-Harmonix Hum Debugger.