This device adds an amount of gain which is preset using the single control. In terms of the guitar, this unit will you to boost your signal for lead work, for changing between guitars when you wish to match their output (eg, humbucker to single coils) or as a permanent boost in a long effects chain where signal loss an be a problem. There is a large amount of gain available from the Micro Amp, so take care when using it with clean signals to prevent distortion. Used with restraint, however, this pedal will add a warm dollop of gain to a flagging signal.