The One Control Minimal Series Black Loop is a two-loop true bypass switcher with two DC barrel outlets. It can be used as an A+B switch, bypass loopers or tuner output / mute switch. The Black Loop has several functions and offers endless possibilities. The Black Loop is a great tool to bypass vintage effects or pedals without true bypass while they are not in use to get them out of the signal chain. In addition to being a true bypass looper, the Black Loop can be used as an AB Box. Simply connect one amp to the Output and the other amp to Send 2. Stepping on the Loop 2 switch will toggle between Send 2 and the Output. You can use the same feature as a tuner output / mute switch if you connect your tuner to one of the Send outputs.