Used MXR M103 Octave Blue Box Effect Pedal

Add unique texture and vintage character to your tone with this used MXR M103 Blue Box Octave Fuzz pedal, offered in excellent condition. This iconic pedal combines heavy fuzz distortion with a fuzzy two-octave-down synth-like effect, producing a gritty, unmistakably analog sound that helped define tones from legendary '70s rock to modern experimental music. Simple to use, it features just two knobs—Output and Blend—for dynamic control over your sound, letting you mix the fuzz and octave signals to your taste. Housed in MXR’s classic blue metal enclosure, it's built like a tank and ready for the road. Powered by a 9V battery or optional power supply, this effect pedal is a must-have for players seeking wild, unpredictable, and distinctive sonic textures. Whether you're expanding your studio setup or adding vintage flair to your live rig, the MXR Blue Box delivers a bold voice in a compact package.