The SB-6 helps remove noise from two channel audio systems stereo guitar racks and pedalboards. Two on-board isolation transformers provide a flat frequency response from 20Hz to 20kHz while removing hum and buzz from ground loops. Dual ground lift switches help further reduce noise and a -15dB pad allows you to handle high volume outputs without distortion. When using the SB-6 before a set of powered speakers or guitar amplifiers a polarity reverse switch corrects frequency cancellation and ensures both speakers play back in phase with one another. The SB-6 is completely passive with no need for power so it s easy to insert into any system to remove noise quickly.