Rolls HE18 Buzz Off Hum EliminatorThe HE18 is a two channel audio hum and buzz remover. Everyone knows how annoying it is to have 60 cycle hum in your sound. Now you can eliminate virtually all ground hum and buzz by simply inserting the HE18 into the audio path. Plus, the unit will convert an unbalanced signal into a balanced signal, and vice versa. This greatly improves overall noise performance. Features: Eliminates ground loop hum and buzz Leaves signal grounds connected. Passive,