The ACS1 models three vintage amp styles crucial to music industry history designated by their places of origin. When running the ACS1 in stereo, one amp can be used through both channels or mix and match amps and cabinets on the left and right channels with the L + R switch. Simply choose the channel you want it to modify, select your amp and cab model, and set your levels. Then flip over to the other channel and choose your amp and cab settings. If you would like to use the same settings on both channels, set the switch to the middle or “+” and dial in all your settings. They will be duplicated on the left and right outputs. • MFSKU 900-1057 • UPC 810424032781