Tape-echo
   HOME

TheInfoList



OR:

Delay is an audio signal processing technique that records an input signal to a storage medium and then plays it back after a period of time. When the delayed playback is mixed with the live audio, it creates an echo-like effect, whereby the original audio is heard followed by the delayed audio. The delayed signal may be played back multiple times, or fed back into the recording, to create the sound of a repeating, decaying echo. Delay effects range from a subtle echo effect to a pronounced blending of previous sounds with new sounds. Delay effects can be created using tape loops, an approach developed in the 1940s and 1950s and used by artists including Elvis Presley and
Buddy Holly Charles Hardin Holley (September 7, 1936 – February 3, 1959), known as Buddy Holly, was an American singer and songwriter who was a central and pioneering figure of mid-1950s rock and roll. He was born to a musical family in Lubbock, Texas ...
. Analog effects units were introduced in the 1970s; digital effects pedals in 1984; and audio plug-in software in the 2000s.


History

The first delay effects were achieved using tape loops improvised on reel-to-reel audio tape recording systems. By shortening or lengthening the loop of tape and adjusting the read-and-write heads, the nature of the delayed echo could be controlled. This technique was most common among early composers of ''
musique concrète Musique concrète (; ): " problem for any translator of an academic work in French is that the language is relatively abstract and theoretical compared to English; one might even say that the mode of thinking itself tends to be more schematic, ...
'' such as Pierre Schaeffer, and composers such as Karlheinz Stockhausen, who had sometimes devised elaborate systems involving long tapes and multiple recorders and playback systems, collectively processing the input of a live performer or ensemble. American producer Sam Phillips created a
slapback echo Delay is an audio signal processing technique that records an input signal to a storage medium and then plays it back after a period of time. When the delayed playback is mixed with the live audio, it creates an echo-like effect, whereby the or ...
effect with two Ampex 350 tape recorders in 1954. The effect was used by artists including Elvis Presley (such as on his track " Blue Moon of Kentucky") and
Buddy Holly Charles Hardin Holley (September 7, 1936 – February 3, 1959), known as Buddy Holly, was an American singer and songwriter who was a central and pioneering figure of mid-1950s rock and roll. He was born to a musical family in Lubbock, Texas ...
, and became one of Phillips' signatures. Guitarist and instrument designer
Les Paul Lester William Polsfuss (June 9, 1915 – August 12, 2009), known as Les Paul, was an American jazz, country, and blues guitarist, songwriter, luthier, and inventor. He was one of the pioneers of the solid-body electric guitar, and his prototype ...
was an early pioneer in delay devices. According to '' Sound on Sound'', "The character and depth of sound that was produced from tape echo on these old records is extremely lush, warm and wide." Tape echoes became commercially available in the 1950s. Tape echo machines contain loops of tape that pass over a record head and then a playback head. An echo machine is the early name for a sound processing device used with electronic instruments to repeat the sound and produce a simulated echo. The time between echo repeats was adjusted by varying head position or tape speed. The length or intensity of the echo effect was adjusted by changing the amount of echo signal was fed back into the signal recorded to tape. A landmark device was the EchoSonic made by American Ray Butts. It is a portable guitar amplifier with a built-in tape echo, which became used widely in country music ( Chet Atkins) and especially in rock and roll ( Scotty Moore). Dedicated machines for creating tape loops were introduced One example is the Echoplex which uses a tape loop. The length of delay is adjusted by changing the distance between the tape record and playback heads. Another is the Ace Tone EC-1 Echo Chamber. With the Roland RE-201, introduced in 1973, Japanese engineer Ikutaro Kakehashi refined the tape delay to make it more reliable and robust, with reduced tape wear and noise,
wow Wow or WoW may refer to: Games and toys *''World of Warcraft'', a massively multiplayer online role-playing game *''World of Warplanes'', an online flight simulator *''World of Warships'', an online naval simulator *''Wizard of Wor'', a 1981 a ...
, and
flutter Flutter may refer to: Technology * Aeroelastic flutter, a rapid self-feeding motion, potentially destructive, that is excited by aerodynamic forces in aircraft and bridges * Flutter (American company), a gesture recognition technology company acqu ...
, additional controls, and additional tape heads. Different effects could be created by enabling different combinations of playback heads. By adjusting the controls and tape speed, musicians could create pitch-shifting and oscillated effects. The RE-201 was used by acts including Brian Setzer, Bob Marley, Portishead, and
Radiohead Radiohead are an English rock band formed in Abingdon, Oxfordshire, in 1985. The band consists of Thom Yorke (vocals, guitar, piano, keyboards); brothers Jonny Greenwood (lead guitar, keyboards, other instruments) and Colin Greenwood (bass) ...
. In the 1970s, Jamaican
dub reggae Dub is an electronic musical style that grew out of reggae in the late 1960s and early 1970s. It is commonly considered a subgenre of reggae, though it has developed to extend beyond that style.Dub: soundscapes and shattered songs in Jamaican re ...
producers used delay effects extensively; Lee Scratch Perry created "lo-fi sci-fi" effects by using delay and reverb on a mixing console test tone and dub techno producers such as Basic Channel introduced delay to electronic music. Digital delay effects were developed with the arrival of digital recording.


Analog delay

Before the invention of audio delay technology, music employing an echo had to be recorded in a naturally reverberant space, often an inconvenience for musicians and engineers. The demand for an easy-to-use real-time echo effect led to the production of systems offering an all-in-one effects unit that could be adjusted to produce echoes of any interval or amplitude. The presence of multiple ''taps'' ( playback heads) made it possible to have delays at varying rhythmic intervals; This allowed musicians an additional means of expression over natural periodic echoes.


Tape-based delay

Delay processors based on analog tape recording use
magnetic tape Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magne ...
as their recording and playback medium. Electric motors guide a tape loop through a device with a variety of mechanisms allowing modification of the effect's parameters. Popular models included Ray Butts' EchoSonic (1952), the Watkins Copicat (1958), Mike Battle's Echoplex (1959), "whose sounds are still being experimented with today", and the
Roland Space Echo The Roland RE-201 Space Echo is an audio effects unit that produces delay and reverb effects. It was produced by Roland Corporation from 1974 to 1990. Roland produced several smaller versions in later years. Background A tape echo device reco ...
(1973). In the Echoplex EP-2, the play head position was fixed, while a combination record and erase head was mounted on a slide, thus the delay time of the echo was adjusted by changing the distance between the record and play heads. In the Roland Space Echo, all of the heads are fixed, but the speed of the tape could be adjusted, changing the delay time. Thin magnetic tape was not entirely suited for continuous operation, however, so the tape loop had to be replaced from time to time to maintain the
audio fidelity Audio most commonly refers to sound, as it is transmitted in signal form. It may also refer to: Sound *Audio signal, an electrical representation of sound * Audio frequency, a frequency in the audio spectrum *Digital audio, representation of soun ...
of the processed sounds. The Binson Echorec used a rotating magnetic drum or disc (not entirely unlike those used in modern hard-disk drives) as its storage medium. This provided an advantage over tape, as the durable drums were able to last for many years with little deterioration in the audio quality.


Oil can

An alternative echo system was the so-called ''oil-can delay'' method, which uses electrostatic rather than electromagnetic recording. Invented by
Ray Lubow Morley Pedals is the name of a guitar effects pedal company, famous for manufacturing wah-wah pedals and other treadle type effects for guitar. Morley pedals use electro-optical circuitry rather than a potentiometer to control the effect. Th ...
, the oil-can method uses a rotating disc of anodized aluminium coated with a suspension of carbon particles. An AC signal to a conductive neoprene wiper transfers the charge to the high impedance disc. As the particles pass by the wiper, they act as thousands of tiny capacitors, holding a small part of the charge. A second wiper reads this representation of the signal, and sends it to a voltage amplifier that mixes it with the original source. To protect the charge held by the particles and to lubricate the entire assembly, the disc runs inside a sealed can with enough of a special insulating oil to assure that an even coating is applied as it spins. The effect resembles an echo, but the whimsical nature of the storage medium causes variations in the sound that can be heard as a vibrato effect. Some early models featured control circuitry designed to feed the output of the read wiper to the write wiper, causing a reverberant effect as well. Many different companies marketed these devices under various names. Fender sold the Dimension IV, the Variable Delay, the Echo-Reverb I, II, and III, and included an oil can in their Special Effects box. Gibson sold the GA-4RE from 1965–67. Ray Lubow himself sold many different versions under the Tel-Ray/Morley brand, starting out in the early sixties with the Ad-n-echo, and eventually producing the Echo-ver-brato, the Electrostatic Delay Line, and many others into the eighties.


Solid-state delay

The bucket-brigade devices (BBD) was developed at Philips in 1969. Delay effects utilizing this technology eventually became available. Notable examples include the Memory Man from Electro-Harmonix, released in 1976 and the Boss DM-2 released in 1981. BBD-based devices offered a convenient alternative to tape delays and
leslie speaker The Leslie speaker is a combined amplifier and loudspeaker that projects the signal from an electric or electronic instrument and modifies the sound by rotating a baffle chamber ("drum") in front of the loudspeakers. A similar effect is provided ...
s but were eventually largely supplanted by digital delays.


Digital delay

Digital delay systems function by sampling the input signal using an analog-to-digital converter. The resulting digital audio is passed through a memory buffer and recalled from the buffer a short time later. Through
feedback Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop. The system can then be said to ''feed back'' into itself. The notion of cause-and-effect has to be handled ...
of some of the delayed audio back into the buffer, multiple repeats of the audio are created. The delayed (''wet'') output may be mixed with the unmodified (''dry'') signal after, or before, it is sent to a digital-to-analog converter for output. The availability of inexpensive digital signal processing electronics in the late 1970s and 1980s led to the development of the first digital delay effects. Initially, digital delay effects were available in more expensive rack-mounted units. One of the first was the Eventide DDL 1745 from 1971. Another popular rack-mount digital delay was the
AMS AMS or Ams may refer to: Organizations Companies * Alenia Marconi Systems * American Management Systems * AMS (Advanced Music Systems) * ams AG, semiconductor manufacturer * AMS Pictures * Auxiliary Medical Services Educational institutions * A ...
DMX 15-80 of 1978. As digital memory became cheaper in the 1980s, units like
Lexicon A lexicon is the vocabulary of a language or branch of knowledge (such as nautical or medical). In linguistics, a lexicon is a language's inventory of lexemes. The word ''lexicon'' derives from Koine Greek language, Greek word (), neuter of () ...
PCM42,
Roland Roland (; frk, *Hrōþiland; lat-med, Hruodlandus or ''Rotholandus''; it, Orlando or ''Rolando''; died 15 August 778) was a Frankish military leader under Charlemagne who became one of the principal figures in the literary cycle known as the ...
SDE-3000, TC Electronic 2290 offered more than three seconds of delay time, enough to create background loops, rhythms, and phrases. The 2290 was upgradeable to 32 seconds and Electro-Harmonix offered a 16-second delay and looping machine. Eventually, as costs came down further and the electronics grew smaller, they became available in the form of foot pedals. The first digital delay offered in a pedal was the Boss DD-2 in 1984. Rack-mounted delay units evolved into digital reverb units and on to digital multi-effects units capable of more sophisticated effects than pure delay, such as reverb and audio time stretching and pitch scaling effects. Digital delays present an extensive array of options, including control over the time before playback of the delayed signal. Most also allow the user to select the overall level of the processed signal in relation to the unmodified one, or the level at which the delayed signal is fed back into the memory, to be repeated again. Some systems allow more exotic controls, such as the ability to add an audio filter and modulate the playback rate.


Looping

While the early delay units with a long delay capacity could be used to record a riff or chord progression and then play over it, they were challenging to work with. The Paradis LOOP Delay, created in 1992, was the first unit with dedicated looping functions such as Record, Overdub, Multiply, Insert, and Replace, which made it more intuitive and user-friendly. Gibson manufactured a slightly improved version as Echoplex Digital Pro until 2006. Its software Aurisis LOOP is also the last loop tool based on a continuous memory structure as used by tape and digital delays. Most following loopers repeat samples and thus have little in common with a digital delay, the exceptions being Maneco's early looper devices, the Boss DD-20 in digital delay mode and the Pigtronix Echolution.


Computer software

A natural development from digital delay-processing hardware was the appearance of software-based delay systems. In large part, this coincided with the popularity of audio editing software. Software delays, in many cases, offer much greater flexibility than even the most recent digital hardware delays. Software implementations may offer shifting or random delay times, or the insertion of other audio effects during the feedback process. Many software plugins have added functionality to emulate the sounds of the earlier analog units. Abundant
main memory Computer data storage is a technology consisting of computer components and recording media that are used to retain digital data. It is a core function and fundamental component of computers. The central processing unit (CPU) of a computer ...
on modern personal computers offers practically limitless audio buffer.


Artistic uses

In popular and electronic music, electric guitarists use delay to produce densely overlaid textures of notes with rhythms complementary to the music. U2 guitarist the Edge uses delay while he plays arpeggios on electric guitar, thus creating a sustained, synth pad-like background. Vocalists and instrumentalists use delay to add a dense or ethereal quality to their singing or playing. Extremely long delays of 10 seconds or more are often used to create loops of a whole musical phrase. Robert Fripp used two Revox reel-to-reel tape recorders to achieve very long delay times for solo guitar performance. He dubbed this technology " Frippertronics", and used it in a number of recordings. John Martyn was a pioneer of the echoplex. Perhaps the earliest indication of his use can be heard on the songs "Would You Believe Me" and "The Ocean" on the album ''
Stormbringer! ''Stormbringer!'' is a 1970 album released by John and Beverley Martyn. It has no connection to Michael Moorcock's 1965 Elric novel of the same name. John Martyn wrote six of the ten songs and Beverley four. The album was recorded under the d ...
'' released in February 1970. "Glistening Glyndebourne" on the album ''
Bless The Weather ''Bless the Weather'' is a 1971 album by John Martyn and marks his return as a solo artist having released two albums with his wife Beverley Martyn. The writing reflects their move from London to Hastings Old Town. When it was released it garn ...
'' (1971) showcased his developing technique of playing acoustic guitar through the echoplex. He later went on to experiment with a fuzz box, a volume/wah wah pedal, and the echoplex on ''
Inside Out Inside Out may refer to: *Backwards (disambiguation) or inverse Books * '' Inside Out: A Personal History of Pink Floyd'', by Pink Floyd drummer Nick Mason * ''Inside Out'', Christian book by Larry Crabb * ''Inside Out'', novel by Barry Eisler ...
'' (1973) and '' One World'' (1977). Martyn is cited as an inspiration by many musicians, including the Edge.


Function

Delay effects add a time delay to an
audio signal An audio signal is a representation of sound, typically using either a changing level of electrical voltage for analog signals, or a series of binary numbers for digital signals. Audio signals have frequencies in the audio frequency range of r ...
. 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. Delay effects typically allow users to adjust the amount of feedback. By feeding some of the delayed audio back into the buffer, multiple repeats of the audio play back (
feedback Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop. The system can then be said to ''feed back'' into itself. The notion of cause-and-effect has to be handled ...
). At low feedback settings, each repeat fades in volume. High levels of feedback can cause the level of the output to rapidly increase (self-oscillation), becoming louder and louder; this may be managed with limiters. The delayed signal may be treated separately from the input audio - for example, with an equalizer. 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 division In music notation, a note value indicates the relative duration of a note, using the texture or shape of the ''notehead'', the presence or absence of a ''stem'', and the presence or absence of ''flags/ beams/hooks/tails''. Unmodified note values ...
s. Delay is used to create other effects, including reverb, chorus, and flanging. Digital delay effects record a sample of audio and play it back. 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. Some digital delays emulate the "gritty, grainy" sound of earlier delay effects.


Haas effect

Short delays (50ms or less) create a sense of "broadening" the sound without creating a perceptible echo, and can be used to add stereo width or simulate double-tracking (layering two performances). The effect is known as the Haas effect, after the German scientist Helmut Haas.


Ping-pong delay

In a ping-pong delay, the delayed signal alternates between two stereo channels.


Multi-tap

In a multi-tap delay, multiple "taps" (outputs) are taken from a delay buffer, each with independent times and levels, and summed with the original signal. Multi-tap delays can be used to create rhythmic patterns or dense, reverb-like effects.


Doubling echo

''Doubling echo'' is produced by adding short delay to a recorded sound. Delays of thirty to fifty milliseconds are the most common; longer delay times become ''slapback echo''. Mixing the original and delayed sounds creates an effect similar to doubletracking, or unison performance.


Slapback echo

''Slapback echo'' uses a longer delay time (60 to 250 milliseconds), with little or no feedback. A slapback delay creates a ''thickening'' effect. The effect is characteristic of vocals on 1950s rock-n-roll records. In July 1954, Sam Phillips produced the first of five 78s and 45s that Elvis Presley would release on Sun over the next year and a half, all of which featured a novel production technique that Phillips termed ''slapback echo''.Rob Bowman. "Phillips, Sam." Grove Music Online. Oxford Music Online. Oxford University Press. Web. 20 Jul. 2016. The effect was produced by re-feeding the output signal from the playback head tape recorder to its record head. The physical space between heads, the speed of the tape, and the chosen volume being the main controlling factors. Analog and later digital delay machines also easily produced the effect. It is also sometimes used on instruments, particularly
drums A drum kit (also called a drum set, trap set, or simply drums) is a collection of drums, cymbals, and other Percussion instrument, auxiliary percussion instruments set up to be played by one person. The player (drummer) typically holds a pair o ...
and percussion.


Flanging, chorus effect, and reverb

'' Flanging'', '' chorus'' and '' reverb'' are all delay-based sound effects. With flanging and chorus, the delay time is very short and usually modulated. With reverberation there are multiple delays and feedback so that individual echoes are blurred together, recreating the sound of an acoustic space.


Straight delay

''Straight delay'' is used in
sound reinforcement system A sound reinforcement system is the combination of microphones, signal processors, amplifiers, and loudspeakers in enclosures all controlled by a mixing console that makes live or pre-recorded sounds louder and may also distribute those sounds ...
s; a straight delay is used to compensate for the propagation of sound through the air. Unlike audio delay effects devices, straight delay is not mixed back in with the original signal. The delayed signal alone is sent to loudspeakers so that the speakers distant from the stage, as in a large outdoor rock festival, will reinforce the stage sound at the same time or slightly later than the acoustic sound from the stage. The delayed signal uses approximately 1 millisecond of straight delay per foot of air or 3 milliseconds per meter, depending on the air temperature's effect on the
speed of sound The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium. At , the speed of sound in air is about , or one kilometre in or one mile in . It depends strongly on temperature as w ...
. Because of the Haas effect, this technique allows audio engineers to use additional speaker systems placed away from the stage and still give the illusion that all sound originates from the stage. The purpose is to deliver sufficient sound volume to the back of the venue without resorting to excessive sound volumes near the front. Straight delay is also used in audio to video synchronization to align sound with visual media (e.g., on TV or web broadcasting), if the visual source is delayed. Visual media can become delayed by a number of mechanisms or reasons, in which case the associated audio must be delayed to match the visual content.


Samples


See also

* Analog delay line * * Digital delay line *
Send tape echo echo delay Send tape echo echo delay (more commonly known as STEED, alternatively known as single tape echo and echo delay) is a technique used in magnetic tape sound recording to apply a delay effect using tape loops and echo chambers. In 2006, while pub ...


Notes


References


External links

* {{Music technology Audio effects Broadcasting Effects units Music looping Sound recording Sound reinforcement system