What Is Delay?

It’s possibly the effect with the most confusing name, but what is delay?

What Is Delay? - TC Electronic Flashback X4 Delay and Looper

The names of effects can be confusing at times. Chorus, Flange, Phaser, Compression – and these are just effects types. Don’t get me started on the names of pedals themselves – Small Stone? Holy Grail? Though special commendation must go to the Dirt and Ernie…

One of the most common effects types with a slightly confusing name is delay. I mean, why would you want to delay an audio signal?

Here, we explain what delay is, and some of the most common uses of this effect…

In the beginning, there was TAPE, Tape, tape…

The reason for the confusion is perhaps because the name ‘echo’ might be more appropriate for this effect. It is the repeating ‘ECHO, Echo, echo…’ effect, where the sound reoccurs but diminishes in volume. However, ‘delay’ relates to the fact that the device works be delaying the source signal before playing it back.

Though the first delay effects were via magnetic tape-based systems, radio stations used line delays before this, employing telephone lines to introduce delays.

Essentially, the station would send a signal hundreds of miles out to a town, then back again, the distance dictating the amount of delay- usually just a few milliseconds. This signal would be mixed with original to enhance the quality.

When magnetic tape became the medium of choice for recording, engineers began to experiment. Some say that Les Paul was the originator of tape delay, but stories differ. However, in the early ‘50s, tape delay effects began to appear.

What Is Delay? - Les Paul

Essentially, these used a loop of tape to record the audio signal. This then passed through multiple play back heads. The distance between these, and the tape speed, dictated the delay time.

Many also allowed the recorded signal to be fed back into the record head (the feed back control), which increased the number of delay repeats, or ‘taps’.

Though tape delays have a unique and desirable tone, they could be unreliable, required servicing, and tapes needed replacing regularly. Plus, delay time was limited to how long the tape loop was, and how slowly the motors would run before the sound degraded too much. Devices such as the Roland Space Echo, and Watkins Copicat are still highly sought after, however.

What Is Delay? - Roland Space Echo

In the 1960s, a device known as the Bucket-Brigade Device (BBD) revolutionised electronics, and the delay. These transistor/capacitor cells slowed down the signal as it passed through.

BBD delay pedals split the signal, with a dry signal passing straight through, and a secondary signal run through the BBD, before being mixed together at the end.

Digital sampling technology changed delays forever, however. Sampling used computer technology to record the signal perfectly. From there, adjusting the delay time, number of taps was a matter of simple mathematics. Nowadays, nearly all delays are digital.

What Is Delay? - Dr Tone Delay Pedal

Uses of delay

There are innumerable different uses for delay effects. Here are some of the most common…

What Is Delay? - Boss RE-20 Space Echo


Slapback delays are very short delays, with (usually) just a single tap. These were often used in blues and country guitar tones, and are very evocative of those styles.

Many vocalists also use slapback style effects, however, one of the most famous being John Lennon.


One of the most useful effects of a delay is for vocal doubling. Again, a single tap is used, and the delay time is reduced to a time that isn’t really perceived as a delay.

The effect is a very subtle chorus-type effect, akin to a double-tracked recording.

Longer delays

Be using longer delays, interesting rhythmical patterns can be introduced to a musical part. Typically, delay times will be set to a note length synchronised to the tempo of the piece being played.

What Is Delay - Boss Tera-Echo

Ping-pong delay

This effect is basically 2 synchronised delays in a single unit. One is routed to the left, and one to the right channel of a stereo output. By setting different delay times that bear a rhythmic relationship (different note lengths, but in the same tempo, for example) complex, shifting patterns can be created.

Modulation effects

Though most delay units don’t have the editing capabilities to create them, all modulation effects (chorus, flange, phaser etc.) are derived from delays.

Put simply, several fractionally delayed signals are modulated in pitch slightly, and then mixed with the dry signal.

What Is Delay? - Common Controls

Common Delay Controls

Delay Time

Pretty self explanatory- this is the time between the dry signal and the delayed signal. Most often, this will dictate the same delay time for subsequent taps, too. However, some complex delays allow different delay times to be assigned to different taps.

Delay time is usually shown in milliseconds. Software delays will usually have a synchronised mode, which will display delay times in terms of note lengths, however.


Basically, this dictates the number of ‘taps’ that a delay will have. At its lowest, there will be one, whilst turned up fully, often a feedback loop will steadily increase in level and drown out the dry signal. You often hear this kind of effect in Dub.

Delay type

One of the great things about digital technology is that it can be used to mimic other bits of equipment. On a typical delay these days, you can to select from different delay types, from analogue BBD type delays, and tape delays, to ping pong delays and more.

Our full range of guitar delays can be found here.

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