For splitting a guitar, bass signal to multiple amps, or a single multi-channel amp. Add in multiple effects, and your tonal possibilities are endless. Or plug two guitars in, reverse. Change guitars with no cable hassles. The Basics Plug into the input and run "A" and "B" out to, two amps. One dirty "A", one clean "B", switch back and forth in real time. Combine both “All On” function, for an awesome "wall of sound". Stereo. Now you have control over two signal chains. Add in effects and create some phenomenal custom sounds. Or you can bi-channel a single amp, with multiple channels. Like "normal"A, and "top boost"B channels. Use in Reverse Plug two (guitar) signals in. One in A and one in B. With one, single output. Toggle which signal, A or B out only. "All On" may create impedance issues, you would be combining two different signals.