Behringer – MicroHD – HD400 2 Channel Hum Destroyer – Used

The HD400 features two channels that can eliminate hum in two mono signals or one stereo signal. Try putting it between a stereo mixer and your power amps for a squeaky-clean sound free of AC hum. It breaks ground loops safely while maintaining the highest sound quality. It can even convert unbalanced signals into balanced without any signal degradation.