MXR’s Blue Box: Classic Yet Contemporary

By Paul Wolfle

A pedal that accurately lowers the signal of an electric guitar two full octaves just by plugging in seemed like a good idea. Adding fuzz to that sub-octave drop sounded even better, so I purchased an MXR Blue Box pedal. Considering Jimmy Page famously used one on Led Zeppelin’s “Fool in the Rain,” I figured buying the same gear was a no brainer. Not so fast.

To say the Blue Box and I initially did not get along would have been an understatement. Humbuckers or single coils, solid or semi-hollow body, nothing worked. With both the blend and volume knobs normally functioning, the pedal did precisely what it was supposed to do. Nevertheless, something was missing. That’s about the time I decided to run an Electro Harmonix Cock Fight wah before the Blue Box. What a world of difference. Somewhere along the way, I also read about using a compressor with the Blue Box in order to increase sustain. As I already had an MXR Custom Comp compressor, that too was added to the rig.

Equipped with Crème T humbuckers, I plugged my custom Delaney® Matt Guitar Murphy model into a compressor, the Cock Fight and then the Blue Box, in that order. The Delaney® axe, tuned one full step lower than standard, was run through a five-watt Hughes and Kettner amp and then into a Blackstar 1×12 cabinet. With the overdrive button on the amplifier off, the wah set to the “cry” position and the fuzz in pre-amplifier mode, the Blue Box gained volume and control. With the blend knob turned to approximately four o’clock, the result was a gated tone, well-suited for messing around with “Fool in the Rain” and other tunes. That’s with the volume near max on the BB.

Just by moving the wah’s toggle switch to the “talk” position, the Blue Box delivered a square wave tone that sounded excellent while matched with Neil Young’s “Cinnamon Girl” riff done as single string runs. I rotated the Blue Box pedal’s blend knob counterclockwise to roughly one o’clock and a 1970s fuzz vibe jumped out when the wah was set to “cry.” Turning the pedal’s blend fully counterclockwise produced a synthesizer-like signal, which worked well with The Offspring’s “Hit That.” When playing two octaves down, everything at or above the 12th fret had a consistently smooth synth feel. But don’t get me wrong; standard tuning or not, the Blue Box often can be an unpredictable monster, similar to the cry of a beached whale, or at least what you think one would sound like.

Using this rig, the top three treble strings on a Fender® Strat equipped with lipstick pickups offered a gritty gnarl to slide guitar picking. Generally speaking, the Electro Harmonix Cock Fight wah offered a palette of sonic options, while the Blue Box’s sub-octave capabilities created a bass synth quake. Meanwhile, the compressor strengthened the signal and smoothed the string attack. But make no mistake: the Blue Box is the core of this arrangement. Slash’s sub-octave fuzz box and MXR’s Sub Machine Octave Fuzz pedal are similar products, but those stompers are also twice the price. At $79.99, the Blue Box pedal is a great piece of gear.