The HEM-331 Hum Eliminator from Hosa is designed to get rid of ground loop problems, such as AC hum or buzz and/or pop noise in any audio system. It can also be used to convert between balanced and un-balanced lines.
The two channel unit features pure audio transmission, 1/4" TRS phone jacks for inputs and outputs and individual ground lift switch on both channels. The unit requires no external power and is housed in a rugged steel enclosure.