1977 Electro-Harmonix Electric Mistress

Model Description:

The original Electro‑Harmonix Electric Mistress flanger was developed by David Cockerell around 1975. Not only was it a great effect in its own right, it was ground breaking because it was claimed to be the first electronic flanger in a stomp box. It stayed in production for around a decade until Electro‑Harmonix went bust. The familiar ‘jet engine’ effect produced is quite distinctive and has been widely used over the years. The Filter mode removes the LFO that controls the sweep, thereby fixing the filter at the point controlled by the Range control, effectively creating a ring modulator-like dissonant metallic chime. The Electric Mistress is one of Electro‑Harmonix’s chunkier pedals, necessary to accommodate the hand drawn circuit boards of the time. Several of these take up quite a bit of space, especially compared to, say, the equivalent tiny MXR units. Original Electro‑Harmonix pedals are becoming quite desirable on the vintage collector market, so expect values to increase significantly.

Pedal Description:

I bought and collected a few original Electro‑Harmonix pedals from new in the 1970s and this is one that I kept, and for very good reason. To my biased ears, the Electric Mistress remains the pinnacle of vintage analogue (or modern digital) flangers. The effect is an exquisite combination of complex and smooth, and it remains unique in the pantheon of filter effects. It runs on 18V, which means that it either eats batteries or requires an unusual external power supply. The cosmetics are slightly tarnished by the same surface rust spots that tend to affect these pedals, including this one. However, the important bit is the sound produced by the original electronics, especially once the power requirements are met. It evokes the spirit of the 1970s and 1980s with its sweet, shimmering, soaring swooshes and wobbly warbles. The static filter is a bit of a one trick pony but little else does it, so it is ‘icing on the cake’. While the appeal is not in the same league as, say, the Big Muff and Memory Man, having a ‘Mistress’ is a guilty pleasure to be embraced and enjoyed.


  • Made in New York City, U.S.A. in 1977
  • The ‘Rate’ knob controls the speed at which the effect cycles
  • The ‘Range’ knob controls the depth of the effect
  • The ‘Colour’ knob controls the intensity of the effect
  • The ‘Filter Matrix’ switch changes between the cycling matrix and the static filter modes
  • Standard footswitch turns the effect on and off
  • Standard ¼” input and output mono jack sockets
  • No LED status indicator
  • 18V DC input or 2x 9V batteries
  • No battery compartment in the base of the unit
  • Philips screws on the top of the pedal
  • Original cardboard box, no instruction manual

Detail Gallery:

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