Bravo Audio Soap 12AU7 Tube Bypass Warm Tube Guitar Booster Button Controls: Volume, Gain, Tone with Shu Guang 12AU7 tube This unit is not voiced for distortion output or even very colored Overdrive tones, but rather adds a second layer of volume and boost to your signal Can be placed in effects loop or in front of the amp to conjure up some nice tones and harmonics Supplied with it's own Power Adapter and ready to go right out of the box. Turning up the Gain will offer some Overdrive tones