Wah-wah pedal

Wah - Wah is an electronic effects unit, which is mainly to influence the sound of an electric guitar used. The term " wah-wah " describes the onomatopoeic sound of the induced effect. The effect ( plunger mute) was created purely acoustic originally in wind instruments using a over the sound hole down the hollow body.

Operation

The " wah- wah" effect is produced by a sound filter which is technically described as a bandpass filter with resonance peak. The special effect is realized by the frequency of the resonance peak in the spectrum back and forth.

The bandpass filter was originally adopted by the communications technology in the electronic music.

In classical embodiment the frequency of the resonance peak is controlled by a pedal. The instrumentalist has his hands continue to play free. The entire circuit is placed in the pedal housing. The pedal position is detected by a special component which influences the resonant frequency by a variable parameter. Mostly it is an actuated with a rack potentiometer. There are design variants in which, instead of the potentiometer a tunable over a movable core inductor ( coil ) or a photoresist is used. The latter is influenced by a system consisting of a light source and an adjustable aperture (light barrier). The technical design has no effect on the sound. Determines the sound level of the resonant peak and the range of variation of the resonance frequency. In some wah-wah pedals can the quality "Q" of the filter change, which allows more sound variations. In the original design, the pedal-controlled component is located directly in the signal processing path. Due to mechanical wear and dust retention structures tend potentiometer with time scratching noise in the output signal. This problem is avoided in the controllable inductor or the light barrier. In newer designs, the resonant frequency is indirectly changed by a control voltage, so it is a VCF (Voltage Controlled Filter ), which is part of each synthesizer.

Such a VCF, since it is regulated by a control voltage, do without pedal; takes the control depends on the input level, it is called an auto- wah -wah or touch. It is controlled only by the strength of the attack, is typical of this effect for the funk music style. Often these effects is implemented in a time-dependent scheme, as it occurs in flanger, chorus or tremolo effects. In this case, the resonance frequency moves up and down in a preselected time interval.

The combination of two Wahschaltungen also allows the simulation of vowels.

Prominent wah-wah users were the electric guitarist David Gilmour, Jimi Hendrix and Eric Clapton. During the 1960s and 1970s In the 1990s, the wah -wah pedal has also found connection in the field of heavy metal, for example, Kirk Hammett of Metallica and Tom Morello of Rage Against The Machine. The effect was also used for sound modification of electric pianos, listen to, for example, by Joe Zawinul with Weather Report in the piece Black Market ( 1975-1976 ). It is particularly characteristic of the radio, where it is used by electric guitar, bass guitar and electronic organ to hear, for example in the music of the band Funkadelic.

Today the effect is used less intensively, including various styles of popular music.

Famous pieces of music with the wah- wah effect

  • Jimi Hendrix: Voodoo Child ( Slight Return )
  • Isaac Hayes " Shaft " soundtrack
  • The Temptations with Wah Wah Watson: Papa Was a Rollin 'Stone
  • Cream: Tales of Brave Ulysses
  • Jimmy Page of Led Zeppelin in the live performances of the play Dazed and Confused, it was excessively used during the violin bow solos; besides, it was an important part of the play No Quarter (as seen on the published DVDs of the group)
  • Peter Frampton: Frampton Comes Alive
  • Metallica: Enter Sandman ( the guitar solo )
  • Guns N ' Roses: Sweet Child o' Mine ( solo )

Known wah types

  • Vox Clyde McCoy 848 - A classic from the 1960s: it was the wah-wah pedal that Jimi Hendrix mainly used.
  • Jim Dunlop Cry Baby ( in different versions ) - the wah -wah, which use, among others, Eric Clapton and Slash.
  • Mutron III - auto-wah, used for example by Stevie Wonder ( keyboards) and Bootsy Collins ( electric bass).
  • Electro -Harmonix Q -Tron - auto-wah, modeled on the Mutron III.
  • Ibanez WH10 - legendary wah pedal that is no longer produced and paid for the higher amounts on the used market. It is used, among other things by guitarist John Frusciante.

Sample

Sample: undistorted electric guitar with wah-wah / i?

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