Removes AC Hum Noise - (2) 1/4-Inch TRS Inputs and Outputs for 2-Mono or 1 Stereo Signal.Breaks Ground Loops Safely - Automatically Converts Unbalanced to Balanced Signal Without Any Signal Loss.Maintains Highest Sonic Quality - High-Performance Ultra-Compact Design - High-Quality Components and Exceptionally Rugged Construction Almost all 60Hz AC hum is caused by ground loops that act like radio antennae (loop antenna). The Hum Eliminator completely eliminates this by breaking the ground loop, making it impossible for the signal lines to pick up the AC hum and noise in the first place. 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 one of the most cost-effective ways to convert between unbalanced signals and true balanced signals. Automatically Translates Signal Voltages to Match Difference in Ground Potentials.