Effect pedal, Preamp Overdrive. The BB Preamp offers a wide variety of sounds. It's capable of a 30dB+ clean boost with an adjustable ±15dB two band active EQ which adds a wide range of harmonic content to your ideal sound. The BB also utilizes a pre-gain stage which allows the pedal to go from a very pristine clean to a very smooth, compressed, overdriven sound. True bypass for eliminating any signal interference when switched off. Can be used with AC adaptor (optional) or 9V Battery.