Pedal Week: The Wah Pedal

Published on 04 June 2019

The world’s most popular effect (next to distortion in all its varieties) is undoubtedly the Wah, or Wah-wah pedal. In it’s heart it’s a simple effect: it’s basically a movable EQ sweep with a pronounced midrange peak frequency that is changed and controlled in real-time by the player rocking their foot on a treadle pedal. This pedal is connected to a potentiometer which allows the peak frequency to sweep up and down in relation to the foot movement. The resultant sound is a definite ‘Wah’ with a strangely human-like vowel sound. There are a number of other sounds that can be achieved using a wah pedal and we’ll approach them soon but firstly, how did this effect even come to be?


The answer is trumpets! Back in the 1920s, trumpet players started getting wise to the expressive tonal changes they could bring about by muting and partially muting the ends of their trumpets as they played. Moving the mute changed the tone accordingly. This type of sound was something that organ players and guitarists wanted too: indeed country legend Chet Atkins designed and built his own unit as far back as the late 50s, as did others but the first recognised manufacture was by the Warwick Electronics Inc./Thomas Organ Company in 1966. Bradley J Plunkett made his prototype by modifying a Vox Continental organ pedal and instantly likening the result to those 1920s trumpet players. Warwick/Thomas entered into a distribution agreement with Vox and it was during this time that Plunkett stumbled upon the magic recipe (via working on circuits from the excellently titled Vox ‘Super Beatle’ transistor amp) of the Wah sound. His associate actually tested it with a saxophone first! Debating on whether this was really better suited for wind instruments or guitar, Vox decided to go with the former primarily and signed up trumpet player Clyde McCoy to endorse it.


The name ‘Cry Baby’ came around after the Thomas organ company wanted to distribute their own products in the states and so a new name was needed. The ‘crying’ sound produced by the pedal was picked up on and thusly used in the name. It was around this time that guitarists started getting interested in the tonal manipulations possible with the Wah. There is a little disagreement on who first brought the Wah sound to the masses but general consensus is that it was either Eric Clapton in Cream’s ‘Tales of Brave Ulysses’ or Jimi Hendrix with his Experience’s song “Burning of the midnight Lamp’; both were released in 1967 and their effect was seismic!


Jimi Hendrix was undoubtedly the King of Wah: his natural timing and ability opened up en entire vocabulary of tones and tricks relative to the Wah pedal: the ‘wacka wacka’ muted-string intro to Voodoo Child (Slight Return); the vocal mimicking ‘talking guitar’ of ‘Still Raining. Still Dreaming’ and a whole bag of tasty licks and feedback squalls filtered and exaggerated by the wah pedal to astounding, original effect.


Other players soon caught on: Jimmy Page, Jeff Beck, George Harrison (who wins extra points for actually writing a song called ‘Wah Wah’), Terry Kath, Tony Iommi, Robbie Kreiger…the list is actually endless. Every player brought their own flair and personality to their wah-wah technique and in doing so made it a pre-eminent sound of the counterculture. Other genres then began to understand what the Wah sound could do for them: for example, where would seventies funk be without those percussive-yet-expressive riffs? It wasn’t just guitar players either: Garth Hudson used one on his clavinet to add some funk to The Band’s ‘Up on Cripple Creek’. Wah had taken over!


Some players like Michael Schenker, Mick Ronson and Mark Knopfler left their Wah pedal switched on and sitting in the middle position of the treadle’s sweep to create a honking, mid-range focused tone that was immediately unique. Great examples of this would be David Bowie’s ‘Ziggy Stardust’ and Dire Straits’ immortal lead riff on ‘Money For Nothing’. It’s a sound that really holds it’s place in a mix and sounds appealingly bizarre!


The Wah pedal has proved to have enjoyed something of an evergreen popularity. Every decade brings along more guitar heroes who state their case for greatness with a Wah pedal seemingly attached to their foot. Slash and Kirk Hammett did a lot in the 80s: in the 90s we had Dimebag Darrell, Zakk Wylde, John Squire of the Stone Roses and perhaps most significantly, Jerry Cantrell of Grunge behemoths Alice in Chains. His atmospheric and heavy riffing was tightly spliced with mercurial, shifting shards of expertly applied Wah guitar.


The pedal itself has hardly changed over the years, despite the amount of models now available! The most significant deviation from the path must be, in our opinion, the Z-Vex Wah Probe. Zachary Vex’s highly unusual pedal trades a typical rocker-treadle pedal for a highly atypical copper plate with an imbedded proximity sensor to let you hover your foot over the pedal in a fashion akin to a theremin! ‘Eccentric’ doesn’t begin to describe it but it’s loads of fun.


Nowadays the Wah pedal is as popular as ever. Most pedal companies offer their version and from Dunlop to Vox, Fulltone to Electro-Harmonix, every pedal has its own flavour. As you'd expect, at guitarguitar, we are very into our wah pedals! Visit us at your nearest store and plug in a wah pedal: embrace the legend and join the ranks of historic players!


Ray McClelland