Effects unit

An effects unit, effects processor, or effects pedal is an electronic device that changes the sound of a musical instrument or other audio source through audio signal processing. These tools help musicians create new sounds and effects that are fun and exciting to listen to.

Common effects include distortion/overdrive, often used with electric guitar in electric blues and rock music. There are also dynamic effects such as volume pedals and compressors, which change how loud the sound is. Filters like wah-wah pedals and graphic equalizers adjust certain parts of the sound. Other popular effects are modulation effects such as chorus, flangers and phasers, pitch effects like pitch shifters, and time effects such as reverb and delay, which add echoing sounds.

Most modern effects use solid-state electronics or digital signal processors. Some older effects, like Leslie speakers and spring reverbs, use mechanical parts or vacuum tubes. Effects are often found as stompboxes, small boxes placed on the floor that are controlled with footswitches. They can also be built into guitar amplifiers, instruments like the Hammond B-3 organ, tabletop units for DJs, and rackmounts. They are also used as audio plug-ins in formats like VST, AAX, and AU.

Musicians, audio engineers, and record producers use effects units during live shows or in studios, often with electric guitar, bass guitar, electronic keyboard, or electric piano. While effects are most common with electric or electronic instruments, they can be used with any audio source, such as acoustic instruments, drums, and even vocals.

Terminology

An effects unit is also called an effect box, effects device, effects processor, or simply an effect. The abbreviation F/X or FX is sometimes used. A pedal-style unit may be called a stomp box, stompbox, effects pedal, or pedal. Unprocessed audio coming into an effects unit is referred to as dry, while the processed audio output is referred to as wet.

A musician bringing many pedals to a live show or recording session often mounts the pedals on a guitar pedalboard, to reduce set-up and tear-down time and, for pedalboards with lids, protect the pedals during transportation. When a musician has multiple effects in a rack mounted road case, this case may be called an effects rack or rig. When rackmounted effects are mounted in a roadcase, this also speeds up a musician's set-up and tear-down time, because all of the effects can be connected together inside the rack case.

Form factors

Effects units come in different sizes and shapes. Stompboxes are small, often operated by a musician's feet during performances. They can change the sound of instruments in many ways, like adding distortion or creating echoing effects.

Rackmount devices are larger and were very popular in studios. They can do more complex sounds but are now less common as smaller, digital options have become available. Some effects are built right into instruments or amplifiers, offering quick and easy sound changes.

History

The earliest sound effects were used in recording studios. Engineers would place microphones in special rooms to mimic different performance spaces. In the 1940s, musicians like Les Paul started using tape to create echo and unusual sounds. The first stand-alone effects unit, the DeArmond Model 601 Tremolo Control, was released in 1941.

Effects built into guitar amplifiers were the first ones musicians used regularly. In the 1950s, guitarists began turning up their amplifiers to get warm, distorted sounds. The first portable effects pedals, called stompboxes, appeared in the 1960s. These small pedals made it easy for musicians to add effects like fuzz, wah-wah, and chorus to their music while playing.

Main article: echo chambers

Other effects include modulation effects like chorus and flanger, which create moving sound textures; pitch effects that shift notes higher or lower; and time effects like reverb and delay, which add echoes and simulate different spaces. Modern effects often use digital technology to achieve these sounds.

Main article: Sound effect § Techniques

Bass effects

Main article: Bass effects

Bass effects are special tools that change the sound of a low-pitched instrument like an electric bass or an upright bass. These tools can make the sound fuzzy or add a wobbly effect, for example. Some bass amplifiers already have built-in sound changers, like making the sound louder or softer. Upright bassists in music styles such as jazz and blues often use a small device called a bass preamplifier. This helps connect the bass to the amplifier or sound system and can also adjust the loudness and balance of different sound frequencies.

Boutique pedals

Boutique pedals are made by smaller companies, often in limited numbers. Some are even handmade, with special details like unique knobs and artwork. These pedals are usually sold online or in a few music stores and tend to cost more than regular pedals because they use higher-quality parts and unique designs. Some of these companies focus on recreating classic effects from the past.

Some well-known boutique pedal makers include: BJFE, Pete Cornish, Emlyn Crowther, Death By Audio, Robert Keeley, Roger Linn, Roger Mayer, Strymon, T-Rex Engineering, ToadWorks, and Z.Vex Effects.

People also enjoy changing or updating effects pedals to improve them. Some sellers offer modified pedals, while others let you choose how you want your pedal changed. Popular pedals for modification include the Ibanez Tube Screamer, Boss DS-1, Pro Co RAT, and DigiTech Whammy. Changes can include swapping parts, adding better components, or giving the pedal new features.

Other pedals and rackmount units

Not all stompboxes and rackmounted electronic devices designed for musicians are effects. Strobe tuner and regular electronic tuner pedals indicate whether a guitar string is too sharp or flat. These pedal-style tuners usually send the guitar signal to a guitar amp to produce sound. Rackmount power conditioner devices help equipment work properly by providing the right voltage. A rackmounted wireless receiver allows a guitarist or bassist to move around on stage without being connected to a cable. Footswitch pedals can route a guitar signal to an amplifier or let a performer switch between two guitars or amplifiers.

Guitar amplifiers and electronic keyboards may have switch pedals to turn built-in reverb and distortion effects on and off. Some musicians use a MIDI controller pedalboard or remote controls to trigger sound samples or change effect settings. A pedal keyboard is a foot-operated keyboard used to play basslines, not an effect unit.

Notable manufacturers

Many companies make special tools that change how musical instruments sound. These tools help create different tones and effects in music. Some well-known companies include BJFE/One Control/Mad Professor, Chase Bliss Audio, Danelectro, Darkglass Electronics, DOD Electronics/DigiTech, Dunlop Manufacturing/Way Huge, EarthQuaker Devices, Electro-Harmonix, Eventide Inc., Fender, Frantone Electronics, Fulltone, Ibanez, JHS Pedals, Keeley Electronics, Line 6, Maxon Effects, Meris, Mesa/Boogie, Mooer Audio, Morley Pedals, Mu-Tron, Roland, Seymour Duncan, Source Audio, Strymon, Supro, T-Rex Engineering, TC Electronic, Tech 21, Universal Audio, Vox, Wampler Pedals, Z.Vex Effects, and Zoom Corporation. These companies offer a wide range of options for musicians to explore new sounds.