MXR Blue Box Pedal

MXR Blue Box M103 — The Octave Fuzz With a Mind of Its Own

The MXR Blue Box is one of the most distinct pedals in the fuzz category. It captures your guitar signal, fuzzes it up, then duplicates it two octaves down — the result is a cavernous, subterranean tone that's immediately identifiable. It's the effect at the heart of Jimmy Page's solo in Fool in the Rain, and it remains one of the most sonically unpredictable tools a guitarist can plug into.

Key Features

• Analog octave fuzz — signal duplicated two full octaves below the input
• Output knob for overall level control
• Blend knob to mix between dry signal and two-octaves-down fuzz effect
• Powered by a single 9V battery or Dunlop ECB003 AC adapter
• Two-knob layout for immediate, straightforward operation
• 100% wet setting for a fully submerged, extreme fuzz experience

Ideal For

The Blue Box suits guitarists who want character over cleanliness. Run fully wet for an extreme, almost unrecognizable effect; dial in dry signal to keep things more controlled while retaining the fuzz texture. It's a natural fit for heavy riffs, experimental rock, and unconventional studio layering — exactly why artists like Munky, Tim Skold, and Zakk Wylde have kept it on their boards.