Where Did the Wah Pedal Come From?

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There’s a long and fascinating history behind the wah pedal we know today. What started out as a trick of brass instrumentalists in the 1920s has evolved into one of the most iconic guitar effects to date.

Wah has been used from jazz and blues to funk, rock, fusion, and more, and it’s all thanks to an accidental discovery by a young engineer working on an amp redesign. 

Whether you love it, hate it, or have no clue what I’m talking about, we’ll explore the interesting origins of this sound effect from its humble beginnings to its funkalicious takeover and beyond. 

What Is Wah?

The Sound Is in the Name

Wah, or wah-wah pedals, have a name derived from one of my favorite linguistic characteristics, onomatopoeia.

The primary sound they produce is right there in the name—wah wah wah wah wah. It’s a sound that’s been compared to crying so much so that the first major line of commercialized wah pedals were named “Cry Baby” pedals.

They’re not, however, limited to this undulating cry effect. Wah pedals can serve as frequency filters when used in a fixed position, allowing the player to emphasize a specific tonal range. Otherwise, they can produce a percussive “wacka-wacka” effect, the sound made famous in the “Shaft” theme song of the 1970s.

Wah is an effect unbounded from genre that can be used in any playing style in which the musician feels experimentally adventurous.


So how’s a wah work? In its simplest incarnation, a wah pedal is a combination of a potentiometer and a foot pedal which turns this pot.

The potentiometer acts as a filter for a range of frequencies. At different positions, it allows certain frequency ranges through while attenuating, or blocking, others. 

The result of this is a modulation known as spectral glide. Spectral glide is a change in the vowel aspect of a tone. You can hear an example of this by singing a note and then changing the position of your lips.

It’s altogether a rather simple innovation that has had a profound impact on guitar music since its invention. 

Wah Pedal on Guitar Pedalboard

First Effects

Early Studio Tones

To understand where the wah pedal history, it’s helpful to know the history of guitar effects as a whole.

As the electric guitar became more mainstream in the 40s, guitarists began looking for ways to create different sounds with their instruments.

To this end, they began experimenting with studio effects, using reel-to-reel recording techniques and various microphone placements to create reverb and echo sounds.


Beginning in the late 1940s, Gibson began designing amplifiers with built-in effects. Other manufacturers soon took to this practice and released amps featuring vibrato, tremolo, and spring reverb modules.


The first true effects pedal was created in 1948 by Rowe Industries. This was the DeArmond Trem-Trol. 

DeArmond’s Trem-Trol was an ingenious effects box made to imbue a guitar’s tone with a tremolo effect. It worked by way of a motor controlling the shaking of a vial of electrolytic liquid. The guitar’s signal passed through this liquid, which as it splashed around in the container, allowed varying amounts of signal to pass through. This modulated the volume of the tone to create a very basic tremolo effect.

This was followed by effects boxes from other brands such as Gibson, Fender, and Watkins, who released units made to deliver vibrato, reverb, and delay. However, these were bulky, awkward, and altogether impractical for use by most musicians, with the exception of the Watkins Copicat, which was the first standalone effects unit to see true commercial success.

Guitarist Playing a Wah Pedal

Birth of the Wah

Crying Brass

Now, though the guitar is the first instrument that comes to most people’s minds when they think of wah, this effect—though not pedal-based—first rose to prominence in trumpets, largely thanks to bandleader Clyde McCoy.

McCoy made extensive use of a piece of equipment known as a mute, by which he was one of the first musicians to popularize the wah-wah sound. Rather than playing through a pedal, the mute was moved in and out of the trumpets bell to create the spectral glide modulation.

A Vox Reinvention

Forty years after McCoy’s initial wah performances, the Beatles crashed into the US with their high-power Vox amplifiers. 

This new wave of Beatlemania increased the American demand for Vox amps, so the company looked for a licensed distributor for their products in the States, ultimately choosing Thomas Organ Company in 1964.

It soon became evident that importing amps from the UK was not a very cost-effective business model, so Vox sold the rights to build their amps to Thomas Organ Company shortly thereafter.

In an effort to maximize profits, the head of Thomas Organs tasked its engineers in redesigning the Vox amp model in a way that preserved their tone but cut down on costs. 

During this process, engineer Brad Plunkett created an alternative to Vox’s pricey mid-range boost switch in the form of a circuit-connected potentiometer dial. In testing the knob, Plunkett found that a guitar running through this system produced a distinctive and alluring “wah-wah” effect when the pot was turned.

In a stroke of genius, Plunkett rigged his new system up to an organ pedal so that the potentiometer could be controlled hands-free, and thus the first wah pedal was born in 1966.

Guitar Player Looking Down at Wah Pedal on Pedalboard

Rise of the Wah Pedal

The management of Thomas Organ Company initially thought to market the new wah pedal as an accessory for brass instruments, but this idea went by the wayside after the pedal was noticed by Vox Ampliphonic Orchestra guitarist Del Casher.

Casher had been a studio musician for both Elvis Presley and Gene Autry before joining this roving band of Vox product promoters. Upon hearing the wah pedal in the Thomas Organ headquarters, he was immediately enamored. 

In a bid to convince the upper management of Thomas Organ of the pedal’s guitar potential, he recorded a demo record. This recording caught the attention of Frank Zappa, who loved the new wild tones he heard on it and hired Casher for a tour. During this tour, Zappa absolutely fell in love with the wah pedal and bought one immediately following its commercial release in 1967.

He then introduced Jimi Hendrix and Eric Clapton to the new wah effect, who in turn put it to great use in hit songs such as “Tales of Brave Ulysses” and “Up from the Sky.” These musicians continued to use the wah throughout their recordings and live performances, boosting it into the spotlight of guitar tone prestige.

By this point, it was evident that trumpeters had no great desire for a wah pedal. So, the stompbox originally named “The Clyde McCoy” after the wah-pioneering 1920s trumpeter was remarketed to guitarists as the Cry Baby, owing to its cry-like voicings.

Funky Vibes and Wacka-Wacka

Shortly following the Thomas/Vox release of the Cry Baby, a late patent and leaking of schematics resulted in a surge of companies manufacturing their own wah pedals.

By this time, it was a prominent feature of many rock acts and was starting to be discovered by funk, soul, and R&B guitarists.

In 1971, the movie Shaft was in production and gave rise to the first rhythmic use of the wah pedal in its hugely popular intro song thanks to the pioneering guitar work of Charles Pitts.

The success of this intro theme caught the attention of many artists of the time and launched the wah pedal into vogue for a huge range of genres, being featured in tons of hits of the 1970s. 

Many of these famous guitar parts were recorded by one man, Melvin Ragin, aka Wah Wah Watson and include “I Will Survive” by Gloria Gaynor, “Papa was a Rollin’ Stone” by The Temptations, and “What’s Going On” by Marvin Gaye.

Wah Pedals’ Brief 1980s Decline

The beginning of the 80s saw a rise in popularity of more digitized effects with the oncoming wave of punk and hair metal. Resultantly, the wah pedal began to fall into obscurity.

Contributing to this was the drop in quality of Thomas Organ’s pedals. They were largely inconsistent in their internal components, so it was rare to find two wah pedals that produced the same effect.

Thomas Organ Company was shut down in 1982, and during their liquidation sale, Jim Dunlop, founder of Dunlop Manufacturing, bought the rights to the wah pedal

Dunlop then spent the better part of a year updating and redesigning the pedal. This paid off in 1984 when Stevie Ray Vaughan recorded his wah-heavy cover of “Voodoo Child”, after which the new Dunlop pedals were picked up and used extensively by 80s hard rockers like Guns N’ Roses and Metallica. 

Return to the Mainstream

Though it had a brief slump in the early 80s, the wah never completely fell out of fashion. With the help of grunge groups like Nirvana and Pearl Jam, the wah pedal continued its journey through the 1990s.

Even amidst technological advancements like computer-generated digital effects, this simple device has maintained its place as one of the most popular guitar tone mods since its 1966 creation.

There are now wah pedals for bass guitar, auto-wahs, and artist-specific models marketed to those trying to dial into their favorite guitarists’ signature tones.

Though the technology has become more refined, the basic mechanics remain the same and the truly unique cry of wah remains a favorite effect of many guitarists today.

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