I'll let the T-Rex website explain this one because they can do it much better than me. I should add, however, that I LOVE this pedal. It's raw, down and dirty and reacts differently with each and every guitar that gets drawn into its pot.. “This baby is designed for those who want an in-your-face wall of guitar sound jumping of the speakers. The boost button and the tone knob enable you to dial in every sound you like right from ultra fuzz to smooth jazz sounds. In “OFF
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