1975 MXR Blue Box

Model Description:

MXR Innovations was founded in 1972 by Keith Barr and Terry Sherwood, based in Rochester, New York, USA and produced original pedals up to 1984 when production ceased. Early models, including the Blue Box (MX‑103), carried the spindly ‘script’ logo which has since become a symbol of desirability on the vintage market. MXR began to replace the ‘script’ logo in favour of the more modern ‘block’ logo from 1976, completing the conversion process by about 1978. By 1981 an LED status light and DC power input had been added. While the model name may aptly describe the physical appearance of the pedal, it gives absolutely no indication whatsoever of what it does, and the control labels don’t really help (‘Output’ and ‘Blend’). What you actually get is two full‑on analogue effects in one tiny blue box – a monophonic octave generator and a gritty fuzz. Over the years, the Blue Box has become popular with bass players as well as guitarists. When switched on, the ‘Blend’ control turned fully anti‑clockwise creates a note one octave down added to the original signal. Turned fully clockwise, the fuzz dominates. In between is a continuum of mixed effect depending on the knob’s position. The Blue Box may sit firmly in the shadow of its more illustrious relatives in the MXR line up, although it has carved out quite a reputation with adventurous experimental and alternative artists. The Blue Box is quite a rare beast and is undeniably cool, ingeniously esoteric and mysteriously ambiguous. Good ones are becoming increasingly valuable amongst knowledgeable collectors. A rejuvenated MXR, under the ownership of Jim Dunlop, wisely reissued the Blue Box for new fans to discover and experience.

Pedal Description:

Now here’s very special American‑made vintage MXR Blue Box. This natty little pedal, dates to 1975 and sports the desirable early ‘script’ logo. As they have always been few and far between, early script logo Blue Boxes in full working order and good condition are hard to find. This example is in fabulous condition and has obviously either been well looked after or stored for much of its life. The footswitch seems to have been replaced at some point. However, it is the original electronics that ultimately count and, oh boy, what an impact this deceptively small device has. The sub‑octave is very typical of its breed and is predictably unpredictable in that it often mis-tracks the original note. Its inability to follow notes accurately, especially with weaker pickups, might lead you to think it isn’t working correctly. Actually, it is operating normally; it’s just a quirky ‘feature’ that contributes to its offbeat impulsive random weirdness. The fuzz is downright dirty and leaves you in no doubt what its sonic intentions are. The bombastic aural onslaught doesn’t really need a tone control and the Level knob adds a boost to make even more of a din should your repertoire require it. What the Blue Box does in spades is to produce some fun, frantic, and frankly far out frequency frenzy, especially when combining the octave and fuzz effects – pure unadulterated noise. Natural sounding, it most certainly is not, but for uproarious experimentation, it scores big time – think Sonic Youth‑type audio mayhem. I love it. Be cool, join the in‑crowd, take a stomp on the wild side and don’t look back at the trail of devastation that this harmonically humongous heavyweight leaves behind.


  • Made in Rochester, New York, U.S.A. in 1975
  • The ‘Output’ knob controls the output volume
  • The ‘Blend’ knob controls the balance between the octave and fuzz effects
  • The standard footswitch turns the effect on and off
  • Replacement ¼” input and output mono jack sockets
  • 1st generation ‘script’ MXR logo, model name and baseplate
  • No LED or DC power supply input – 9V battery only
  • No box or instructions

Detail Gallery:

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