In this video, take a trip back to the origins of ‘delay’ as an effect and the technologies that led us to where we are today.
Early delay systems
The first delay effects were achieved using tape loops improvised on reel-to-reel magnetic 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 (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. Audio engineers working in popular music quickly adapted similar techniques, to augment their use of plate reverb and other studio technologies designed to simulate natural echo. Tape echoes became commercially available in the 1950s.
Before the invention of audio delay technology, music employing a delayed echo had to be recorded in a naturally reverberant space, often an inconvenience for musicians and engineers. The popularity of an easy-to-implement 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.
Many delay processors based on analog tape recording, such as Ray Butts’ EchoSonic (1952), Mike Battle’s Echoplex (1959), or the Roland Space Echo (1973), used magnetic tape as their recording and playback medium. Electric motors guided a tape loop through a device with a variety of mechanisms allowing modification of the effect’s parameters. In the case of the popular Echoplex EP-2, the play head 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 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 of the processed sounds.
The Binson Echorec, another popular unit, used a rotating magnetic drum 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. Other devices used spinning magnetic discs, not entirely unlike those used in modern hard disk drives.
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 is widely acclaimed as the 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 released in February 1970. This was a first taste of things to come from Martyn’s interest in electronics and the boundless possibilities of electric music. Glistening Glyndebourne on the album Bless The Weather (1971) showcased his developing technique of playing acoustic guitar through the echoplex to stunning effect. He later went on to experiment with a fuzz box, a volume/wah wah pedal and the echoplex on highly acclaimed Inside Out (1973) and One World (1977). Martyn is cited as an inspiration by many musicians including U2’s The Edge.
Often incorporating vacuum tube-based electronics, surviving analog delay units are sought by modern musicians who wish to employ some of the timbres achievable with this technology.
Solid state delay units using analog bucket brigade delay circuits became available in the 1970s and were briefly a mainstream alternative to tape echo. Though solid state analog delays are less flexible than digital delays and generally have shorter delay times, several classic models such as the discontinued Boss DM-2 are still sought after for their “warmer”, more natural echo quality and progressively decaying echos. Additionally, several companies make new analog delays. Old delay systems like the Roland Space Echo and Echoplex are still highly regarded and used with some frequency by modern bands.
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, they were only available in expensive rack-mounted units but eventually as costs came down 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 timescale-pitch modification effects.
The earliest known design, possibly the first, was prototyped at a Boston-based sound reinforcement company in 1976. The core technology used a Reticon SAD1024 IC. This chip and design found its way into the well known Rockman amplifier some years later. In the 1980s, this design was used by BOSS for their mass production product.
Early battery guitar delay design, 1976 Digital delay systems function by sampling the input signal through an analog-to-digital converter, after which the signal is passed through a series of digital signal processors that record it into a storage buffer, and then play back the stored audio based on parameters set by the user. 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.
Many modern digital delays present an extensive array of options, including a 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 buffer, to be repeated again. Some systems today allow more exotic controls, such as the ability to add an audio filter, or to play back the buffer’s contents in reverse.
As digital memory became cheaper in the 1980s, units like Lexicon PCM84, Roland SDE-3000, TC Electronic 2290 offered above 3 seconds 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.