Rolls HE18 2-Channel Hum And Buzz RemoverThe Rolls HE18 Buzz Off is a low cost, 2 channel, in line audio hum and buzz remover, which virtually eliminates 60 cycle ground hum and buzz in the audio path. In addition to hum removal, the unit converts unbalanced signals into balanced signals, and vice versa, improving overall noise performance. Eliminates ground loop hum and buzz Leaves signal grounds connected Passive unit, no power required Converts balanced lines to unbalanced lines and vice