An audio effect is an effect that alters a musical instrument or other audio source through audio signal processing.

Common effects include distortion and overdrive, often used with electric guitar in electric blues and rock music; dynamic effects such as volume pedals and compressors, which affect loudness; filters such as wah-wah pedals and graphic equalizers, which modify frequency ranges; modulation effects, such as chorus, flangers and phasers; pitch effects such as pitch shifters; and time effects, such as reverb and delay, which create echoing sounds and emulate the sound of different spaces.

Effects may be applied through electronic devices, such as effects units, effects pedals, and rackmount units, or through software. Most modern units use solid-state electronics or digital signal processors. Some, particularly older units such as Leslie speakers and spring reverbs, use mechanical components or vacuum tubes. Effects are often placed on the floor and controlled with footswitches. They may also be built into guitar amplifiers, instruments (such as the Hammond B-3 organ), tabletop units designed for DJs and record producers, and rackmounts. In software, they are widely used in digital audio workstations as audio plug-ins in such common formats as VST, AAX, and AU.


Unprocessed audio is referred to as dry, while processed audio is referred to as wet.[1]

Types edit

Delay edit

 
The tape mechanism of a Roland RE-201 delay unit

Delay effects add a time delay to an audio signal. When the wet (processed) audio is blended with the dry (unprocessed) audio, it creates an echo-like effect, whereby the original audio is heard followed by the delayed audio.[2]

Delay effects typically allow users to adjust the amount of feedback (the number of times the delayed audio is played back). At low feedback settings, each repeat fades in volume; high feedback can cause the delayed sound to increase in volume.[2]

Most delay effects also allow users to set the delay time, or the amount of time between each audio playback. The may be synchronized to a BPM, allowing users to set time values as beat divisions.[2] Delay is used to create other effects, including reverb, chorus and flanging.[2]

Digital delay effects record a sample of audio and play it back.[2] Software versions record the audio to a buffer. Digital delay may also modify the recorded sound, by reversing it, altering its pitch, or other manipulations.[2] Some digital delays emulate the "gritty, grainy" sound of earlier delay effects.[2]

The first delay effects were created in the 1950s by using tape, and was used by artists including Elvis Presley and Buddy Holly.[3] Dedicated tape delay units, such as the Roland RE-201, made the effect accessible to more artists.[4] Digital delay effects were developed with the arrival digital recording.[5]

  1. ^ Hodgson, Jay (2010). Understanding Records, p.95. ISBN 978-1-4411-5607-5.
  2. ^ a b c d e f g "The ultimate guide to effects: delay". MusicRadar. 7 June 2011. Retrieved 2021-06-12.{{cite web}}: CS1 maint: url-status (link)
  3. ^ Blitz, Matt (2016-08-15). "How Sam Phillips invented the sound of rock and roll". Popular Mechanics. Retrieved 2021-06-12.{{cite web}}: CS1 maint: url-status (link)
  4. ^ Dregni, Michael. "The Roland Space Echo". Vintage Guitar. Retrieved 2021-06-13.{{cite web}}: CS1 maint: url-status (link)
  5. ^ "The ultimate guide to effects: delay". MusicRadar. 7 June 2011. Retrieved 2021-06-12.{{cite web}}: CS1 maint: url-status (link)