MXR Brown Acid Fuzz PedalThe MXR Brown Acid Fuzz delivers psychedelic silicon saturation to guitar and bass players who like it low, slow, and heavy. Based on a classic 1970s UK fuzz circuit, this pedals simple three knob interface allows you to plug in and tune out in no time at all. Dial in the Output, Tone, and Fuzz controls to set the mood, and then let the heaviness flow forth as the world around you melts into a fuzzy, synesthetic convergence of colors and sounds.