Ernie Ball WAH

What a wah does

A wah is a filter you play with your foot. Technically, it is a band-pass filter that rolls off both treble and bass and creates a resonance peak that you sweep up and down as you rock the pedal¹. Vox describes the effect as a shifting band-pass filter with a highly resonant peak². JHS puts it more plainly: a wah is a variable mid-frequency equalizer with a boost attached³.

The sound was not originally aimed at guitar. The wah was made to replicate the sound of a trumpet, and its inventor intended it for trumpet players³⁴. On guitar it produces the vocal, crying sweep heard all over funk and rock records. One of the first recordings of the effect on electric guitar was "Burning of the Midnight Lamp" by the Jimi Hendrix Experience, released in 1967⁵.

Mechanically, most wahs since the late '60s have used the same idea: a rocking footbed attached to a potentiometer, running the signal through a capacitor to attenuate the high end⁶. You rock the pedal with your foot to sweep the frequency, which is why the design borrowed an organ's volume pedal from the start⁷.

Where a wah goes in the signal chain

The near-universal advice is to put the wah early in the chain:

JHS: put your wah pedal first, then all your other pedals after it³.
BOSS: place this filter effect directly after the tuner and before the drive section, so the signal frequency is optimized before overdrive, distortion or fuzz pedals shape it⁸.
Guitar World: a standard wah pedal generally sounds best in the very front of the signal chain, with a pitch shifter or harmonizer placed in front of it if you use both⁹.

Most wah pedals have an inductor in their circuitry, and an inductor is essentially a coil of wire that can act like an antenna. Morley advises not placing a wah above or next to a power supply¹⁰.

Who invented the wah pedal

The wah was an accident. The Wah-Wah pedal was invented in November 1966 by Lester Kushner and Brad Plunkett, working at Warwick Electronics, a division of Whirlpool that owned Thomas Organ Company and Vox¹¹. Vox's own history says the effect was discovered during the design of the VOX Super Beatle amplifier in 1966².

The commonly told version: in 1965, engineer Brad Plunkett was reworking a Vox amp to make it cheaper to produce, and while replacing the amp's midrange boost switch with a potentiometer he found that sweeping the frequency created a dramatic "wah" tone⁷. His solution was to adapt an organ's volume pedal to control the circuit with a foot, and the first wah pedal was born⁷. JHS dates the invention to 1966, with Vox producing it as a product in 1967¹².

Wah on bass

Wah is not just a guitar effect. Wah has been popular with both funk and rock bassists since the early 70s, when Bootsy Collins and Geezer Butler turned players on to it¹³. Several makers now build dedicated bass wahs:

Pedal	What the maker says
Dunlop Cry Baby Bass Wah	"The first wah pedal designed by bass players for bass players."⁴
Caline CP-72 Bass Wah/Vol	A wah response tailored for bass plus a volume function, usable in clean or gain settings¹⁴
EBS Stanley Clarke Wah/Tone Filter	A signature wah/tone filter that can also be used as a volume pedal

JHS's buying advice cuts against the combination units: don't buy a device that does wah and volume, because you end up with a "jack of all trades, master of none" situation; buy a dedicated wah³.

For more on specific models, see the Dunlop EVH-95 Eddie Van Halen Signature Wah Wah, the Snarling Dogs Super Bawl Whine-O Wah and the Vox Wah Wah, or browse all bass pedals.

Questions

Where should a wah pedal go in the signal chain?

Most advice puts the wah at the very front of the chain, directly after the tuner and before your drive pedals. JHS recommends putting the wah first with everything else after it, and BOSS says placing it after the tuner and before the drive section optimizes signal frequency before distortion shapes it. One practical warning: most wah circuits contain an inductor that can act like an antenna, so keep the pedal away from power supplies.

Who invented the wah pedal?

The wah was invented in November 1966 by Lester Kushner and Brad Plunkett, engineers at Warwick Electronics, a division of Whirlpool that owned Thomas Organ Company and Vox. Plunkett discovered the effect while reworking a Vox amplifier circuit, and the design was finished by adapting an organ volume pedal so a player could sweep the frequency with a foot.

Is a wah pedal used on bass?

Yes. Wah has been popular with funk and rock bassists since the early 70s, when players like Bootsy Collins and Geezer Butler made it part of the sound. Several makers build dedicated bass wahs, including the Dunlop Cry Baby Bass Wah, described by Dunlop as the first wah designed by bass players for bass players.

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