A good power distribution system is essential for proper operation of audio system. Professional audio systems just doesn’t work well with normal extension cords running hundreds of feet to a stage. Besides the power feed the good grounding of thw whole system is essential.
Ground loop is a condition where an unintended connection to ground is made through an interfering electrical conductor. Generally ground loop connection exists when an electrical system is connected through more than one way to the electrical ground.
When two or more devices are connected to a common ground through different paths, a ground loop occurs. Currents flow through these multiple paths and develop voltages which can cause damage, noise or 50Hz/60Hz hum in audio or video equipment. To prevent ground loops, all signal grounds need to go to one common point and when two grounding points cannot be avoided, one side must isolate the signal and grounds from the other.
If you are a guitar player or you have a handle the audio system band with lots of guitarists then ground loop is an important thing to keep in mind. As even the best electric guitars and other equipment can face trouble if ground loop is an issue.