Ground Loops can occur for several reasons but the most common is that your electronic devices are connected via audio patch cords but the power cords are connected to different wall socket receptacles.



The easiest way to avoid the hum and ground loops is too distribute all your power chords from a single wall receptacle. This provides something similar to a Star Ground scheme.



Add up the current requirements of all the electronic devices to determine how many amps you need available at the wall receptacle. Make sure you stay below the safety limit or you will blow a circuit.