The PHE300 Mini 2-Channel Hum Destroyer from Pyle Pro is designed to completely eliminate 60Hz AC hum caused by ground loops that act like radio antennae (loop antenna). It features 1/4" TRS inputs and outputs on each of its two channels.
The hum elimination process is accomplished by breaking the ground loop, therefore eliminating the possibility of signal lines picking up the AC hum and noise. Unbalanced lines are more susceptible to picking up electrical noise and RF interference than balanced lines - the longer the unbalanced cable, the greater the chance of a problem. Using this device to connect two pieces of equipment is a cost-effective way to convert between unbalanced signals and true balanced signals. The PHE300 automatically translates signal voltages to match the difference in ground potentials as it is a level and impedance matching device.