Something that lends itself to giving the electric guitar its versatile reputation, is the fact that an electric guitars output can be modified, manipulated and tweaked by various effect processors and other electronic sound products. Guitar electronics manufacturers like Digitech, Zoom and Boss have a range of guitar effect pedals in their product line ups, which guitarists can use to radically change their sound or add subtle nuances to it.

Guitarists have many effects at their disposal, such as time based effects and modulation effects. These pedals can either come in tiny compact floor pedals; where one pedal will specialize in producing one type of effect; or a large multi effect pedal where there are hundreds of options available to the discerning guitarist. For guitarists who have enough moolah to splurge on pedals, a “pedal board” would be preferred over a multi-effect pedal. Pedal boards are basically a variety of different effect pedals which are daisy chained together to create a signal path (the path through which the guitars output signal travels through before it reaches the amplifier) with many effects in between the amp and the guitar. To cater to such guitarists, most pedals come with “bypass” modes which allow the guitars signal to pass through the pedal without being effected by that pedals particular effect.

The Effects

Wah Pedals (EQ/Tone effect)

This is a very expressive effect that matches the vocal “wah” sound. The “wah” creates a peak in the frequency spectrum and moves this peak either up or down according to how much the pedal’s rocker is moved. As the rocker moves down, the peak is moved up, creating a “wa” sound, and as the rocker is pulled up, the peak moves down, creating a “ow” sound. When a soloist uses this type of pedal effectively, it produces a titular WAH! There are also “auto wah” pedals which either change the peak’s position according to a set parameter or which produces the wah sound depending on how loud the guitar signal is, so the harder u play, the more “wa” you hear and the softer you play, the more “ow” you hear. Wah pedals are usually placed very early in the signal chain. It can be used after a distortion pedal to create a fatter sound. Pedals like the Dunlop Crybaby and the Ibanez Screaming Demon are examples of high quality Wah pedals.

Phasers (Modulation effect)

These pedals produce a massive “whooshing” sound. When used on a clean guitar signal, it makes a very subtle effect which adds ambience to acoustic tracks. When used with distorted guitar signals, it produces a gargantuan wall of sound! This effect is created when notches (the opposite of a peak- a cut in level across a narrow range of frequencies) are automatically moved up and down the frequency spectrum. This effect is often confused with the Flanging effect, however the Flanging effect is a delay based effect where the notches are related harmonically. These effects are usually placed after overdrive or distortion pedals to create an obnoxious “air plane” sound. The Smallstone phase shifter is an example of a Phaser effect pedal

Compression (Level/Dynamics effect)

A compressor effectively controls the volume of a guitars signal, boosting soft passages and limiting loud licks. It is often used by studios to make sure guitar tracks sound clear and focused. It is rarely detectable by listeners as it is not an obvious effect. Compression also adds sustain to a guitar; the louder signals are cut down to a certain level and as the note fades, the signal is boosted up back to the set level. The Boss CS-3 is an example of a compressor pedal, and compression pedals are usually placed first in the signal path.

Overdrive, Distortion and Fuzz ( Distortion effect)

The main purpose of this effect is to produce the sound of an over driven amplifier which is pushed up to the point where the signal distorts. This is the most commonly used effect. Overdrive is achieved by producing “soft clipping” where the gain is reduced to a point just below clipping so the result is a smooth, natural sounding effect with an array of even order harmonics (those which are harmonically related to the note). Distortion is achieved by using “hard clipping” which produces a harsher sound and produces odd order harmonics. Fuzz sounds fatter and produces odd order harmonics. Pedals like the Digitech Death metal produce distortion and the Boss DS-1 produces over drive.

Equalizers ( EQ or Tone effect)

These pedals usually use moving sliders to graphically represent the level of fixed frequencies. This allows the guitarist to alter the level of each frequency, thereby shaping the overall frequency response of the guitars signal. These equalizers can be used anywhere in the signal path.

Octave Dividers (Pitch based effect)

These effects copy a guitar signal and change the pitch of the copied signal. Then the 2 signals are combined. These usually work with one note at a time because many notes would confuse the octave divider. These are usually placed after a compressor as this effect works best with an even signal. The Boss OC-3 is an octave divider

Pitch Shifters (Pitch based effect)

This effect adds one , or more, pitch shifted voices to the notes played. This is similar to an octave divider but the player can set the harmony voices to fixed intervals such as 4 semitones up or 7 semitones down. This comes in handy when attempting to emulate a 12 string guitar. These pedals are usually placed after compressors and distortion pedals but before time based pedals like delays.

(Photo credit: lucam)