Electro-Harmonix Electric Mistress

The Electric Mistress is an analog flanger made by Electro-Harmonix, designed by David Cockerell and first sold in 1976¹². Premier Guitar calls the original "the first commercially available flanger"³, and MusicRadar's Simon Bradley calls it "a truly iconic stompbox"⁴. What sets it apart from most flangers is its reach: MusicRadar's Alex Lynham describes it as "a flanger whose delay line range goes all the way into chorus territory," though it keeps the resonant feedback that makes a flanger a flanger⁵.

What the Electric Mistress does

A flanger mixes a delayed copy of your signal back with the original, with the delay time swept by an LFO so the two copies cancel at moving frequencies. That produces the jet-like sweep players know from flangers. The Electric Mistress's delay line is unusually wide for the type: as Alex Lynham put it in MusicRadar, "The Electric Mistress has a range that goes all the way into chorus territory. Of course, it's not a true chorus," because it retains the resonant feedback of a flanger⁵. Guitar.com's Huw Price notes that the pedal's "filter matrix" setting demonstrates comb filtering, the underlying cancellation effect, before flanging⁸.

Electro-Harmonix leans into both sides of that character. The company lists the Stereo Electric Mistress as a "Flanger / Chorus" and says its "lush stereo flange and chorus work together," with an individual flanger and individual chorus available¹. MusicRadar's Trevor Curwen, reviewing the Epitome multi-effect that includes a Stereo Electric Mistress section, notes it "can provide both flanger and chorus sounds," with "individual blend controls for flanger and chorus allow[ing] you to use both at once"⁹.

The controls: Rate, Range, Color and the Filter Matrix switch

The classic control set, shared by the original, the Deluxe and the XO reissue, is three knobs plus a switch¹⁰¹¹:

Filter Matrix mode is the pedal's signature trick. Electro-Harmonix describes it on the Stereo Electric Mistress as a way to "manually flange your sound or select a flange point allowing musically frozen tonalities"¹. On the Deluxe Electric Mistress XO, the company explained that "the modulation waveform is disconnected from the flanger circuit, freezing the flanger and creating a matrix of filters"¹³. MusicRadar's Trevor Curwen, reviewing a compact clone, points to "that signature metallic whine you get when switching a Mistress to Filter Matrix mode" as part of the design's character¹⁴.

The Stereo Electric Mistress handles the mode differently: as Premier Guitar's reviewer explained, "EH found a clever way to combine the Filter Matrix with a normal rate control sweep into one pot." From 6 to 10 o'clock the Rate knob controls the Filter Matrix; from 11 o'clock on it controls the speed of the rate¹⁶. The Stereo version also adds a Flanger Depth knob that "controls the amount of Flange that is mixed with the direct signal"¹.

Power: 18V originals, 9V later units

Power is where the versions differ most in practical terms. Premier Guitar's modulation history notes that "while more recent examples of the EHX Electric Mistress Flanger/Filter Matrix are 9V, the original versions were 18V"². Delicious Audio identifies the late-'70s "V2" Electric Mistress as an 18-volt flanger¹⁵, and Pedal of the Day likewise points to "the classic 18v Electric Mistress" behind David Gilmour and Andy Summers tones¹⁶.

The later, current-format pedals run on 9V-class supplies:

• Stereo Electric Mistress: 9.6VDC-200mA power adapter included; no battery operation¹
• Deluxe Electric Mistress (final version): 9.6VDC-200mA power adapter included, with an optional 9V battery not included⁷
• Deluxe Electric Mistress XO: standard EHX 9.6-200mA supply included, or a 9 volt battery¹³

The versions and how they differ

Premier Guitar's Neo Mistress review flagged "one of the real drawbacks of the Electric Mistress and Deluxe Electric Mistress is their large footprint"¹⁷, which the XO and Stereo versions addressed with compact die-cast packages¹¹³. The Deluxe Electric Mistress is listed by Electro-Harmonix as discontinued in 2023⁷, and Guitar World reports the company rebranded it as the Andy Summers Walking On the Moon pedal¹².

What reviewers said

Reviewers have consistently praised the sound while noting practical drawbacks. Guitar World's best-of-EHX guide credits the Deluxe Electric Mistress with a "rich, warm sound" and a rugged design, names it the guide's pick for flanger, and warns it "can leave you feeling seasick"¹⁰. Of the Stereo Electric Mistress, Premier Guitar's reviewer found "the flanger gives you a good range, from subtle waves to jet-like swoops"⁶.

On That Pedal Show, Dan named a vintage Electric Mistress among his joint favorite effects pedals of all time, calling it the pedal that got him into pedals, while describing it as "a noisy little box that sounded better than the state-of-the-art stuff of its day"¹⁸. In the channel's six-flangers comparison, the pair demo "the unmistakable sound of a 1970s electric mistress"¹⁸.

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Who uses it: Andy Summers and David Gilmour

Two players above all are tied to the pedal. Andy Summers used an Electric Mistress for his signature modulation in The Police's early years, creating the shimmering textures on "Walking on the Moon" and "Message in a Bottle"¹⁹²⁰²¹. When Electro-Harmonix built his signature pedal, Summers himself was surprised by the labeling: MusicRadar reported that he "would have called it a chorus"²⁰. Guitar World calls the rebranding "the final definitive proof that he used a flanger and not a chorus pedal" on those songs¹².

David Gilmour famously used the original Electric Mistress from Animals onward²², mainly for slow sweeping flange effects on his solo and Pink Floyd albums during the late '70s and early '80s¹². Delicious Audio notes the late-'70s 18V V2 was used in his live and studio recordings both as a solo artist and with Pink Floyd¹⁵.

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