Guitar 101: What Is a Wah-Wah Pedal? Learn About the Different Types of Wah-Wah Pedals

A wah-wah pedal is a tone filter—also called an envelope filter—that a musician can control with his or her feet. Most electric guitars contain a tone knob that, depending on its position, either creates a bass-heavy timbre (think of jazz guitar tones) or a treble-focused one (think of country, surf music, and funk).

The wah-wah pedal gets its name for its similarity to the human voice, which can also rapidly glide through tonal frequencies.

A guitarist rarely adjusts the tone knob during a song: it’s controlled by the right hand (on a standard guitar), which the guitarist needs for picking. A wah pedal simply transfers this tone control to a foot pedal.

• When the wah is rocked all the way back (i.e. the heel end is depressed), it serves as a low-pass filter: low frequencies pass through and higher frequencies are blocked.
• When the wah is rocked all the way forward (ie. the toe end is depressed), it becomes a high-pass filter, allowing treble to cut through at the expense of bass.
• When you rock the pedal back and forth, it creates a spectral glide, often known as the “wah effect.”

The first wah pedal was issued in 1966 by the Thomas Organ Company, owned by the same parent company that made Vox amplifiers. This pedal was not, however, the first tonal sweep effect:

• Trumpet players had been creating “wah wah” effects for decades. To hear an example, listen to Bubber Miley’s lead trumpet on the Duke Ellington Classic “East St. Louis Toodle-O.” (This was ironically covered by the jazz/rock band Steely Dan—using a guitar with a wah pedal.)
• Guitarists like Chet Atkins and Peter Van Wood had also been experimenting with tone shifting pedals, mostly for “novelty” effect.
• Within a year of its invention, the wah-wah pedal was already appearing on prominent recordings. Eric Clapton can be heard using one on the Cream records Disraeli Gears (1967) and Wheels of Fire (1968). Jimi Hendrix debuted his wah pedal on Electric Ladyland (1967).
• Many other players followed suit, from Jimmy Page to Terry Kath of the band Chicago.

The wah-wah pedal is featured on many classic recordings throughout popular music. Here is a small sampling:

• Isaac Hayes, “Theme From Shaft” (1971). This repeating guitar pattern—more rhythmic than melodic—is played by Hayes’ guitarist Charles Pitts. It almost single-handedly created the association between the wah pedal and funk music, as well as “sexy” music in general.
• Bon Jovi, “Livin’ on a Prayer” (1986). This hit single features Bon Jovi lead guitarist Richie Sambora using both a wah pedal and a “talk box”—creating even more of a vocal effect. The main riff uses both effects, but the guitar solo is pure wah.
• The Jimi Hendrix Experience, “The Burning of the Midnight Lamp” (1967). This relatively mellow, spiritual song was many listeners’ first exposure to the wah sound. Hendrix uses it to double a keyboard line he based the song around.
• The Band, “Up On Cripple Creek” (1969). A reminder that the wah pedal isn’t just for guitar. On this track, Garth Hudson uses it to filter a clavinet, thus creating a jaw harp effect.
• Metallica, “For Whom The Bell Tolls” (1984). This track features a bass with a wah pedal, a signature of the now-deceased Metallica bassist Cliff Burton. But within the band, it’s actually lead guitarist Kirk Hammett who’s most associated with the wah (he uses one on virtually every solo).

There are many excellent wah-wah pedals on the market today, and they remain among the best-selling guitar effects. Here are some particularly great wah pedals.

• Dunlop Cry Baby series. Jim Dunlop makes approximately 30 variations on the original Cry Baby wah. Some are modeled to the tastes of specific players, like Slash, Joe Bonamassa, and Clyde McCoy. Others, like the 535Q, include a wide variety of tonal filters to select from.
• Vox V847A. Designed to be remarkably similar to the original Vox wah pedal issued in 1966.
• Morley Steve Vai Bad Horsie 2. This wah pedal, co-designed by the famed shredder Steve Vai, includes a unique shape and independent volume and tone controls.
• MXR MC404 CAE. Like nearly all wahs, this is modeled off the original Thomas Organ Company design, but includes component upgrades like dual Fasel inductors to create a higher-end product.
• Keeley Neutrino Envelope Filter Auto Wah or the Boss AW-3 Dynamic Wah Pedal. Another option is an auto-wah pedal, which provides a constant envelope sweep. This can’t be as readily controlled as traditional wahs, and so they are less popular. But be warned: these pedals sound pretty different from traditional wah.

Learn more about guitar effects in Carlos Santana’s MasterClass.