What Are Delay Pedals (Guitar Effects) & How Do They Work?
A single delay pedal in a guitarist's rig can add numerous dimensions to his or her playing. It's no wonder why delay pedals are so popular on pedalboards around the globe, spanning across nearly all genres of music.
What are delay pedals, and how do they work? Delay pedals are stompbox effects units that cause a time-based delay effect in the guitar/instrument signal. Delay pedals essentially “record” the dry signal and play it back one or more times after a set time interval(s). Delay pedal types include tape-based, analog, digital and modelling units.
In this article, we'll discuss delay pedals in much more detail, getting into each type of delay, how they work, and what they sound like. I'll share a few pedal examples along the way and tips on how to get more out of your delay pedal.
Related My New Microphone articles:
• The Ultimate Effects Pedal/Stompbox Buyer’s Guide
• Top 11 Best Guitar/Bass Effects Pedal Brands To Know & Use
• Top 13 Best Delay Pedals For Guitar & Bass
Table Of Contents
- What Is The Delay Effect?
- What Is A Delay Pedal?
- Types Of Delay Effects
- What About Analog/Digital Hybrid Delay Pedals?
- Controls Of Delay Pedals
- Tips On Using A Delay Pedal
- Where Should Delay Pedals Go In The Signal Chain?
- A Note On Looper Pedals
- Other Effects That Use Delay
- Related Questions
What Is The Delay Effect?
Before we get into this article, let's first discuss the delay effect (in more words than the opening answer paragraph).
Delay, as an audio effect, is the process of recording an input signal to a storage medium and playing it back (often along with the input signal) after a period of time.
The processed/delayed signal can be played back once or multiple times, depending on the delay effect unit. The delayed signal level can often be adjusted along with the mix relative to the original dry signal. It may also be fed back into the delay processing circuit to produce further delay.
If we compare the audio delay effect to the world of acoustics, it would be analogous to the initial reflections we'd hear after a sound bounces off a reflective surface.
We can often hear “delay” in the real world as the sound is reflected around us. However, the delay is all too often drown out, when it's noticeable at all, by the reverberation of the environment.
Note that reverb, like delay, is a time-based acoustic reaction that has been turned into an audio effect.
Related article: What Are Reverb Pedals (Guitar Effects) & How Do They Work?
Of course, the audio effect known as delay can be manipulated much more than the natural acoustic reflections of the real world.
We'll get to this later, but the main four parameters of any delay effect, which allow us to dial in and manipulate the effect, are as follows:
- Effect level: the relative amplitude of the delayed signal, often in relation to the dry/input signal.
- Delay time: the amount of time between the initial signal and the delayed signal.
- Repeats: the number of times the signal is repeated before trailing off.
- Feedback: how much, if any, of the delayed signal is fed back into the delay circuit.
Delay can be set to recreate space in the real world. It can also be used to give quick slapback effects, spacey echoes, stereo widening, and other effects.
Back to the table of contents.
What Is A Delay Pedal?
A delay pedal is an effects unit that produces audio delay and is built in the form of a stompbox.
Delay pedals are often used by guitarists and bassists, as well as keyboardists and synth players.
Related articles:
• Do Guitar Effects Pedals Work With Bass Guitar?
• Do Guitar Pedals Work With Keyboards & Synthesizers?
Delay pedals are incredibly popular and for good reasons. Nearly every musician can benefit from a good delay pedal. This is true whether it's used subtly to add depth and space to signal, to create atmospheric cascading guitar tones, or anything in between.
It makes sense, then, that there are plenty of delay pedals on the market (and many that have come and gone from the market over time).
To sum things up, a delay pedal is a stompbox delay unit. It is typically designed to be controlled by the player's feet. It will usually have the common control parameters of the delay effect, namely effect level, delay time, repeats and feedback.
Related article: What Is A Guitar Effects Pedal And How Do Pedals Work?
Back to the table of contents.
Types Of Delay Effects
So delay is a time-based effect that records an incoming signal and plays it back at defined intervals to produce a sort of “echo” effect in the audio signal. Delay pedals of all sorts are designed to produce this effect in guitar (and other instruments) signals and are designed in a stompbox format.
That's the basics. However, not all delay effects are the same. In fact, there are several different types of delays.
The main types of delay (and delay pedals) are as follows:
Let's talk about each in a bit more detail to further our understanding.
Tape Delay
The first type of delay effect ever conceived was tape delay.
Tape delay, as the name suggests, uses magnetic tape. The same tape that was (and still is used) in analog recording studios.
Tape delay, historically, has been achieved by routing the audio signal to a second tape recorder. The audio would be fed to the secondary tape's record head and be played back just milliseconds later on the playback head. This delayed playback signal would be sent back to the main recording.
Here is a simple illustration of a tape machine:
The erase head ensures the tape is blank before it hits the record head. The tape machine's input signal is sent to the record head and is recorded onto the passing tape. Moments later, the play head reads what has been recorded onto the tape and sends this signal to the machine's output.
The delay time of this tape echo effect is adjustable by altering the speed of the secondary tape machine. Multiple repeats are achieved by feedback, which is the act of re-routing the delayed signal back into the secondary tape machine.
Note that delay time and feedback are standard controls on modern delay pedals.
These tape machines were often tasked with producing what is largely referred to as “slapback delay”: a fast-acting delay with a single repeat. However, feeding the delayed signal back into itself to produce longer delay tails was/is not uncommon in practice either.
Tape delay machines became commercially available in the 1950s. Mike Battle's Echoplex (invented in 1959) is a well-known example.
These tape delay effects units (this includes tape delay pedals) utilized proprietary tapes that would loop continuously in relatively small cartridges.
A tape delay pedal effectively controls a tape machine within its housing and can output both the affected/delayed signal and dry signal. Optimized controls such as wet/dry (effects level), delay time and feedback are standard for these stompbox units.
A typical tape delay pedal setup will resemble something like this (all inputs to the left and all outputs to the right):
This is the basic setup for any type of delay circuit. For analog and digital delays, simply replace the “tape machine” with “solid-state analog circuitry” or “digital-signal-processor”.
Basically, the pedal will have two signal paths: the direct signal path and the delayed signal path.
The direct signal path simply passes the input signal to the output [relatively] unaffected.
The delayed signal path takes the input signal and passes it through the delay circuit (in this case, the tape machine). The output of the delay circuit will be connected to the output mixer to be combined with the direct signal. The delayed signal may also be routed back into the delay circuit via the feedback loop.
Many “tape delay” pedals on the market are actually only modeller pedals designed to emulate the character of tape delay. That being said, there are certainly real tape delay pedals and machines available on the new and used markets today.
The tone of tape delay, whether it's achieved by actual tape machines or by emulation, can be defined by three phrases:
- Tape saturation: this is the soft-clipping distortion of analog tape being overdriven. Setting the input level high on a tape delay can yield this warm and pleasant distortion to some degree.
- Filtered repeats: each repeat in a tape delay gets “worse” in quality, particularly in the high end. This adds warmth and space to the tape-delayed signal.
- Slight chorusing: the moving parts of an actual tape delay machine make absolute precision impractical. The subtle speed variations of the moving tape cause slight variations in the pitch of the repeats, similar to a vibrato or chorus effect.
A great example of a modern, true tape delay pedal is the T-Rex Engineering Replicator.
Analog Delay
The aforementioned tape delay is certainly analog. However, tape delay units are sometimes difficult to use with all the moving parts and nearly always have shorter lifespans than their newer counterparts.
So then, what is an analog delay? Analog delay, generally speaking, refers to a solid-state delay effects unit.
Just remember that, technically, tape delay is also analog, though I digress.
When it comes to [solid-state] analog delay pedals, the key ingredient in their design is the bucket-brigade device (BBD). More specifically, the birth of the analog delay came from a 1969 BBD chipset from Philips Research.
It wasn't until 1981 that Boss released its DM-2: the first-ever analog delay stompbox pedal.
Boss is featured in My New Microphone's Top 11 Best Guitar/Bass Effects Pedal Brands To Know & Use.
So what are bucket-brigade devices and BBD chips, and how do they work in analog delay pedals?
Well, let's begin by stating that analog delay pedal design is rather involved. Before we get started in the explanation of how analog delay pedals work, let's have a holistic idea of their layout and signal flow.
A typical analog delay pedal setup will resemble something like the following diagram. Hopefully, you can see it. All inputs are to the left of the individual processors, and all outputs are to the right of the individual processors.
There are effectively two main paths for the input signal to travel: the direct signal path and the delayed signal path. Let's run through the individual units of each path to get an idea of what processes we should understand.
The input signal passes through a high-pass shelf filter before being split into two paths.
Let's begin with the direct signal path:
- The high-passed input signal flows directly to the output mixer.
- The output mixer combines the direct signal with the delayed signal.
- The output from the output mixer passes through a low-pass shelf filter to undo the effect of the high-pass shelf filter at the beginning.
- The filtered signal is outputted from the pedal.
Now let's discuss the delayed signal path:
- The high-passed input signal flows to the effect input mixer. This mixer combines the dry signal with any delayed signal in the feedback loop.
- The mixer outputs the signal into a compressor.
- The compressor outputs a compressed signal into an anti-aliasing filter.
- The anti-aliasing filter outputs the signal into the bucket-brigade device (which is controlled by the clock). The BBD delays the signal.
- From the output of the BBD, the signal passed through a reconstruction filter.
- The reconstruction filter outputs the signal into an expander.
- The output of the expander feeds the feedback loop, which connects back to the effects input mixer. It also feeds the input of the output mixer that combines the direct signal with the delayed signal.
- The output from the output mixer passes through a low-pass shelf filter to undo the effect of the high-pass shelf filter at the beginning.
- The filtered signal is outputted from the pedal.
For more information on high-pass filters, check out the following My New Microphone articles:
• What Is A Microphone High-Pass Filter And Why Use One?
• Audio EQ: What Is A High-Pass Filter & How Do HPFs Work?
Let's begin by discussing the central component (the BBD) and work our way outward from there, shall we?
The Bucket-Brigade Device
BBDs are essentially a network of capacitors connected in cascade (the output of the first capacitor feeds the input of the second capacitor, the output of the second capacitor feeds the third, and so on).
The term “bucket brigade” comes from an outdated fire-fighting technique in which a line of people (capacitors) passed buckets of water one person at a time (per clock cycle) until the end of the line where the bucket could be dumped (outputted) on the fire.
Each capacitative element/block creates a time difference (delay) between their input and output as the capacitor is charged and discharged. These blocks are carefully designed to ensure low distortion and noise.
BBDs affect continuous (analog) audio waveforms. However, they are controlled by a clock signal.
The Clock
The clock signal can be thought of like a metronome with a ticking pulse. Each pulse communicates to the BBD that it's time to move the audio from one bucket (capacitor) to the next.
The rate (or delay time) control on an analog delay pedal will control the speed of the clock, thereby controlling the length between repeats in the outputted signal.
In reality, we need two clocks with equal speed and opposite phase. One clock will control the even-number capacitors, and the other clock will control the odd-numbered capacitors. As one clock causes its capacitors to “open”, the other clock causes its capacitors to “close” and vice versa. The main point to understand, though, is that there is a clock at all!
The clock signal can be produced with analog components that create a low-frequency oscillator (LFO) in the shape of a square wave. An inverter can be used for the opposite-polarity copy.
The clock can also be produced with a digital microcontroller. You may be thinking that that would make the pedal digital. Well, yes and no. A digital clock would obviously put a digital component in the pedal. However, the audio signal itself would be 100% analog the entire way.
Digital clocks, in general, are much more versatile than analog clock signals. In the case of delay pedals, they may afford us extra functionality such as tap tempo, MIDI controllability and the ability to save and recall presets.
Because of the clock setup, BBD analog delays have sample rates and are prone to aliasing. The first time I heard this, I was very confused. My entire career as an audio technician and musician, I believed that only digital audio had sample rates and the potential for aliasing.
At each pulse of the clock, the capacitors of the BBD will store a certain amplitude. In other words, the BBD, as a whole, is sampling the input signal at a rate equal to the ticking of the clock.
This sampling can be understood in the following diagram.
This is very similar to digital audio though it is technically still analog. The major difference is that the amplitude of digital audio is quantized to fit a certain value in a certain bit-depth (16-bit, 24-bit, etc.). The amplitudes of the BBD are continuous, meaning they are not quantized to the nearest digital byte.
So the BBD, controlled by a clock (whether the clock is analog or digital), is analog even though it samples audio.
Any type of sampled audio is subject to aliasing at high enough frequencies.
Aliasing is defined as the misidentification of a signal frequency, introducing distortion or error. This happens if the sample rate is too slow to capture the continuous signal's waveform effectively.
Aliasing can be visualized with the following illustrations:
As we can see, it is possible to have a clock sampling rate that is too low to capture the audio signal accurately. We could have a situation like the second illustration where a much lower frequency signal is sampled rather than the true waveform.
Like having a sample rate that is too slow, we could also be trying to sample audio with frequencies that are too high.
The higher the sample rate, the higher the resolution of the sampled signal and the closer the sampled/discrete signal will be to the original continuous signal. This is true of digital signals and BBD delay circuits.
To avoid aliasing, the Shannon theorem states that the sample rate (clock frequency) must be at least twice as fast as the highest frequency of the input signal being sampled.
Unfortunately, we have to strike a balance in a BBD. A faster clock yields more accurate results but has shorter delay times. A slower clock will get us longer delay times but will cause unwanted aliasing in the signal.
That is why BBD delays are limited in their delay times. A few hundred milliseconds will generally be the point at which aliasing makes the delayed signal too distorted to use.
So far, we've discussed the benefits and shortcomings of BBD-type delays.
To get the most out of the BBD/clock analog sampling system, we must condition the audio signal. Let's discuss the other components that make an analog delay pedal practical.
The Anti-Aliasing Filter
We know that aliasing is bad. Therefore, anti-aliasing filters are put in line before the BBD.
The anti-aliasing filter is a simple low-pass filter that removes any harmonic content from the incoming signal that would not respect the aforementioned Shannon theorem.
The trick with this filter is to have it set to not interfere too much with the original signal. This, again, is part of the reason why analog delays have limited delay times and a rather dark sound.
The Reconstruction Filter
The reconstruction filter is put immediately after the BBD to help make the signal “sound analog again”.
Remember that the BBD/clock is an analog sampler. The waveform outputted from the BBD will resemble the input signal but will have discrete jumps in amplitude.
I'll repost the sampling illustration from earlier:
This means there are sharp jumps in amplitude and these square-like steps are a cause of distortion and saturation. Oftentimes, this saturation will show up as increased harmonic content and even as the introduction of new harmonics.
The reconstruction filter is another low-pass filter that aims to reduce this saturation/distortion without overly affecting the overall tone of the signal.
This filter also works to rid of the clock ticks that are inherent in having a clock signal running the BBD.
This is yet another reason why analog delays sound dark.
The Compressor & Expander
To further condition the signal for the BBD, most analog delay pedals will have a compressor before the BBD (and the anti-aliasing filter) and an expander unit after the BBD (and reconstruction filter).
The capacitors of the BBD and the clock are inherently noisy. The compressor/expander helps to reduce this noise.
So first, the signal is compressed, which reduces the dynamics of the signal and increases sustain by bringing the quieter parts of the single closer to the louder parts of the signal in terms of amplitude.
The compressed signal (which sounds different from the dry signal) passes through the anti-aliasing filter, BBD, and reconstruction filter. It picks up noise and gets EQed significantly in the process.
The expander at the other end acts to undo the compression by increasing the dynamic range. As it drops the quieter parts of the signal back down to their natural level, it also drops down the noise.
So although it seems like the expander and compressor are only there to undo each other, they are actually cleverly included to improve the signal-to-noise ratio of the delayed signal dramatically.
A Simplified Holistic View Of The Analog Delay Pedal
Let's simplify our diagram of the basic analog delay pedal signal flow by consolidating the delay circuit into a single unit:
This looks a lot cleaner. Now that we understand how the delay circuit works, we can finalize our understanding of the entire system.
The High & Low Shelving Filters
To further condition the signal, analog delay pedals will generally have a high-shelf filter at the input and a low-shelf filter at the output.
The high-shelf at the input will boost the treble of the signal and recover noise in the BBD and overall delay circuit.
The low-shelf at the output will effectively cancel out the high-shelf at the input and restore the original signal tonality.
The tone of analog delay, whether achieved by actual BBD chips or by emulation, can be defined as dark, warm and nuanced.
The Electro-Harmonix Memory Man is a legendary analog delay pedal. Its first iteration was introduced all the way back in 1976.
The MXR M169 Carbon Copy is a prime example of an analog (bucket brigade device) delay pedal.
The Deluxe Memory Man and Carbon Copy pedals are featured in My New Microphone's Top 13 Best Delay Pedals For Guitar & Bass.
Electro-Harmonix and MXR
Electro-Harmonix and MXR are featured in My New Microphone's Top 11 Best Guitar/Bass Effects Pedal Brands To Know & Use.
Analog delays are inherently flawed. We can see that by how many extra circuits are required just to get a decent sound. The filtering, compressing, expanding. It's quite a lot to think about.
There must be a cleaner way to create a delay pedal.
Digital Delay
Delay pedals are the cleanest and most versatile types of delay pedals on the market today.
Rather than using tape or the BBD-based analog delay circuits mentioned above, digital delay pedals utilize digital signal processing (DSP) to create their delay effect.
Let's have a look at a simplified illustration of a digital delay pedal's signal flow:
As we can see, the main setup is similar to the typical delay pedal. The difference is the digital signal processing unit(s).
Two additional units are critical for the digital delay pedal design:
- Analog-to-digital converter (ADC): this will convert the analog input signal (and feedback signal) into digital audio so that the DSP unit(s) can process it.
- Digital-to-analog converter (DAC): this will convert the digitally-delayed signal back into analog to be sent to the output and feedback loop of the pedal.
With DSP, we can achieve results that are beyond the capabilities of tape and bucket-brigade devices. Digital delay circuits can have extremely long delay times and can repeat the same sound back indefinitely without any signal degradation (other than the losses from the ADC and DAC).
Digital processing is beyond the scope of this article. The main point here is that digital delay pedals are extremely versatile.
Early digital equipment may have suffered from the conversions from analog to digital and back to analog. Many of today's pedals have 24-bit resolution or greater and sound superb.
Of course, purists would argue that any conversion degrades the signal. While it's true that it certainly does, to an extent, it's also true that tape and BBD delays cause severe degradation to delayed signals in terms of EQ and distortion. Pick your poison!
Digital delay is often cherished (and criticized) for being bright, clean, clinical and exact in its reproduction and delaying of the original audio signal.
The Boss DD-8 is a fantastic example of a digital delay pedal.
The DD-8 is featured in My New Microphone's Top 13 Best Delay Pedals For Guitar & Bass.
Boss
Boss is featured in My New Microphone's Top 11 Best Guitar/Bass Effects Pedal Brands To Know & Use.
Digital Emulation Delay
It bears repeating how versatile digital signal processing has become.
With a well-planned digital circuit, we can pretty much emulate any other type of delay.
Remember the filtering, saturation, chorusing, and other “imperfections” that give tape and analog delay pedals their sonic character? All of this can be programmed digitally to mimic the sound of these non-digital devices.
So we can get these old-school effects in a new-school stompbox. Better yet, many digital delay emulation/modeller pedals come with a variety of different delay types to choose from.
The Strymon TimeLine is an excellent example of a digital delay pedal that can emulate both analog (bucket-brigade) and tape delay tones.
The TimeLine is featured in My New Microphone's Top 13 Best Delay Pedals For Guitar & Bass.
Strymon
Strymon is featured in My New Microphone's Top 11 Best Guitar/Bass Effects Pedal Brands To Know & Use.
The Dunlop EP103 Echoplex is a digital pedal designed to emulate the sound of tape delay. To be more specific, this pedal was made to emulate the tones of the EP-3 tape echo unit. It has a digital signal processor for the effected signal and an all-analog dry signal path.
Shimmer Delay
Shimmer is worth mentioning here, though it's not necessarily a new delay circuit.
Shimmer is essentially a delay combined with a pitch-shifter. The delayed signal is pitch-shifted (typically upward) to give a “shimmer” to the overall sound.
More often than not, these shimmer pedals utilize a digital delay circuit.
The Electro-Harmonix Canyon is a great example of a shimmer delay pedal, combining delay with pitch-shifting.
This versatile digital pedal also has settings for a digital delay, a reverse delay, a tape delay, a Deluxe Memory Man emulation and many more settings, including a looper. By that token, the Canyon can also fit into the “Digital Emulation Delay” category discussed above.
The EHX Canyon is featured in My New Microphone's Top 13 Best Delay Pedals For Guitar & Bass.
Reverse Delay
Reverse delay can be achieved via digital means. Its circuit is similar to the others except, of course, for the reverse effect circuit.
Let's have a loop at a simplified signal flow chart for a reverse delay effect pedal:
In this setup, the delay circuit acts as a buffer. It effectively records the audio before it is sent to the reverse effect circuit.
This buffer is necessary since we cannot reverse any signal in real-time. There has to be a buffer of recorded audio that can then be processed. This is why reverse delay pedals will lag behind the first note played.
Note that the reverse and delay circuits are likely to be digital and that there will be ADC and DACs are necessary.
Like the other pedals, there is a feedback loop to feed the delayed signal back into the delay loop (note that it's the delayed signal rather than the reversed signal). The reverse delay pedal design also typically has an output mixer to blend the dry and affected signals together.
The Danelectro Back Talk is a popular example of a reverse delay pedal.
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What About Analog/Digital Hybrid Delay Pedals?
Sometimes you'll see a delay pedal marketed as a hybrid between analog and digital.
This typically means one of three things:
- Its delay circuits are all analog but the clock (and perhaps other controller components) are digital.
- Its delay circuit is digital but the direct signal is outputted 100% analog.
- It's a digital delay circuit that emulates an analog delay sound.
Back to the table of contents.
Controls Of Delay Pedals
Delay is a very versatile effect. Part of this versatility comes from the adjustable parameters.
Here are the controls we'll most often find on delay pedals:
Effect Level (Wet/Dry)
This control blends the direct “dry” signal level with the delayed “wet” signal level at the output mixer.
Delay Time
This controls the length of each repeat, or how long of a period will pass before the first repeat is heard.
Analog and tape delays are limited in their max delay times (typically no more than a few hundred milliseconds). Digital delays can have much longer delay times.
Feedback
Feedback controls the level of the delayed signal that is fed back into the delay circuit. This control is sometimes labelled as “Repeats”.
Turning the feedback control up will lead to more and more repeats of the original signal. Turning the feedback down will generally yield a single repeat which is great for slapback delay sounds.
Turning the feedback control way up can get us into self-oscillation territory where the feedback input can continuously drive the delay circuit itself. Turning up beyond this point will cause a positive feedback loop that can quickly cause the pedal (and subsequent pedals and amplifiers) to become overloaded.
Tap Tempo
Tap tempo is achievable with a digital clock and can, therefore, be integrated into analog and digital pedals.
Tap tempo, as the name suggests, registers the tempo of a tap button. We can tap the tempo with our feet and have the delay time sync up to the pulse we programmed by tapping on the pedal.
Preset Recall
Digital delays may have the added functionality of saving and loading presets. If that's the case, we can dial a setting in, save it, and recall it later.
These presets are typically selectable via the pedal itself.
Model/Mode
Digital emulation/modeller delay pedals will often have several different models or modes to choose from. They will be selectable from the pedal itself.
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Tips On Using A Delay Pedal
Delay pedals can be used in many different ways. Their versatility is one of the many reasons why they are so popular. There's just so much that we can do with a simple delay pedal.
Here are some tips to help get the most out of your delay pedal.
- Give it a break
- Play with delay time
- Think of time and space
- Add sustain to lead lines and solos
- Try out slapback delay
- Produce ambience
- Experiment with the wet/dry mix
- Modulate
- Play with self-oscillation
- Err on the side of shorter delay times in a mix
- Utilize stereo outputs and direct outputs
- Try multiple delay pedals
Give It A Break
This may seem counter to the title of this section, but it's an important point to start on.
To get more out of your delay pedal, use it less. While not “technically” correct, using your delay pedal(s) sparingly will make their effects stand out and become more noticeable than leaving the pedal on at all times.
If the delay pedal is on at all times, then the effect becomes a bit less special and the performance a bit less dynamic.
Play With Delay Time
This one should be obvious but adjusting the delay time is a great way to get more out of your delay pedal.
If the pedal has presets, we can set different delay times for different songs in a set. Alternatively, we can manually adjust delay times between songs (or use multiple delay pedals in our rig with different times for different songs).
Try setting the delay time to the song's tempo or subdivisions of the song's rhythm. This can really lock in the guitar signal to the music.
Sometimes, however, in the age of super clean digital audio, having the delay time set a bit faster or slower than the tempo can add some extra character and interest to the sound.
Think Of Time And Space
As we've discussed, delay is a time-based effect. The same is true of reverb.
We can think of delay, then, as an effect that places our guitar (or other instruments) in real acoustic space.
Just as an echo can be heard reflecting off a surface in an acoustic environment, a delay pedal can give us a sense of the guitar's location in the audio mix.
Shorter delay times with faster decay can make the guitar sound close to the listening in a small acoustic space.
Longer delay times can give the listener the sensation that the guitar is in a large acoustic space. Adjusting the wet/dry mix can place the guitar closer or further from the listener.
Adding more repeats to a long delay time can put the guitar past any physical acoustic limitation, and we can imagine the signal being larger than life.
Add Sustain To Lead Lines And Solos
Perhaps my favourite use of delay pedals is to add sustain to guitar solos.
This ties into the tip on giving the delay pedal a break.
We can keep our signal dry (if the music calls for a dry signal) and engage the delay pedal during a solo to give the soling instrument a heightened sense of space and interest. A nice delay can really make the solo pop out of the mix and grab the listener's attention.
Try Out Slapback Delay
Slapback delay is a common style of delay that, typically, features a single repeat at a fast, often quarter note or eighth note, rate.
Slapback gives a close-up sense of space and can be used to great effect in many genres of music.
To get a slapback effect, set your delay pedal to about 50/50 wet/dry mix with a quarter note delay time (tempo dependent) and barely any feedback.
Produce Ambience
Awe-inspiring ambiences can be produced with a delay pedal by turning up many of the controls.
Having long delay times and plenty of feedback will produce larger-than-life ambiences.
Experiment With The Wet/Dry Mix
Mess around with the wet/dry mix control (often labelled as “effects” level).
Some cool effects can come from removing the dry signal from the output or making it significantly lower in level than the delayed signal.
Modulate
This can be a bit tricky while playing. However, if at all possible (perhaps by sending a loop into the delay pedal), try turning knobs while audio is going through the delay pedal.
Adjusting the delay time control will certainly yield some interesting results as the pedal recalibrates to the new delay time. This tweaking often causes an interesting pitch-shifting effect.
Play With Self-Oscillation
Cranking the feedback control all the way up will likely cause the delay pedal to begin self-oscillating. This happens when the feedback signal is enough to drive the input of the delay circuit perpetually.
Now, modulating the controls (as mentioned in the previous point) can be done without necessarily having to play the instrument continuously.
Be careful not to send too much signal back into the input. This may cause an unpleasant stacking of sound and can even damage your amplifier (and ears).
Doing this can produce an almost synth-like tone from the guitar pedal. It can sound terrible, but it can also be dialled in for a great effect.
Related article: What Are Synth Pedals (Guitar/Bass FX) & How Do They Work?
Err On The Side Of Shorter Delay Times In A Mix
Long delay times are great for ambience, special effects and certain genres of music. However, long delay times can also cause muddiness in a mix, especially if the song is “busy” with a lot of notes or other instruments.
Be careful not to overdo it on the delay in the context of the great mix.
Utilize Stereo Outputs And Direct Outputs
Many delay pedals have either stereo outputs, direct and effected outputs or both.
Try sending each output to its separate amplifier or its own preamp in the studio. This can yield an awesome stereo effect and give us more control over our delayed tone.
Try Multiple Delay Pedals
This tip requires more than one delay pedal.
Try sending the output of one delay pedal into another. This cascading could, in theory, apply to infinite pedals, but 2 should give us an interesting sound.
Adjust delay times or sync the pedals together if possible (via tap tempo functionality). With two delay pedals, we can really dial in some interesting rhythms into the delay effect.
Some pedals, like the Strymon DIG, feature two delay circuits to achieve this effect (and often much more).
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Where Should Delay Pedals Go In The Signal Chain?
Delay is a time-based effect and, therefore, works best near the end of a signal chain or, rather, after the utility, gain-based and modulation pedals (which pretty well sum up all pedals except delay and reverb).
By having the delay pedal at or near the end of the signal chain (just before the amplifier), the delay circuit will have a strong dry signal to effect.
It also means that the pedals before the delay pedal will not be tasked with effecting a “wet” delayed signal. Most pedals will perform better when shaping the tone of a dry signal than when trying to shape a signal with delay.
Of course, experimentation is also a fun exercise and putting delay pedals earlier in a signal chain can yield interesting (and usable) sounds as well!
To learn more about ordering pedals in your rig/pedalboard, check out my article How To Order Guitar/Bass Pedals (Ultimate Signal Flow Guide).
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A Note On Looper Pedals
If we think about how delay pedals work, we can see how looper pedals were developed as extensions of delay pedals.
Remember that a delay pedal will essentially record and playback the initial signal at certain time intervals.
A looper pedal will record/sample a given length of audio and repeat it ad infinitum until it is stopped. This effect, of course, is much different than delay, but it stems from the same principle.
Many modern digital delay pedals will have additional looping functionalities built into their design.
The legendary Line 6 DL4 Delay Modeler features a variety of delay emulations and a 14-second loop sampler.
The Line 6 DL4 is featured in My New Microphone's Top 11 Best Looper Pedals For Guitar & Bass.
Line 6
Line 6 is featured in My New Microphone's Top 11 Best Guitar/Bass Effects Pedal Brands To Know & Use.
For more information on looper pedals, check out my article What Are Looper Pedals (Guitar/Bass FX) & How Do They Work?
To learn about all the pedal types, check out my article The Full List & Description Of Guitar Pedal Types.
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Other Effects That Use Delay
Before we wrap up this article, I'd like to discuss a few other effects that utilize delay.
Chorus and flanger effects utilize delay to achieve their modulation effect. Let's quickly discuss each effect here.
Chorus Pedals
The chorus effect begins its magic by copying the input signal one or more times. Each copy of the signal will be exactly the same as the original (amplitude, frequency, phase position, etc.).
The copied signal(s) are then slightly delayed, creating phase difference(s) between the direct signal and the copy/copies.
The amount of delay each copy experiences is modulated via a low-frequency oscillator (LFO). This causes variation in the wavelength and, therefore, frequency/harmonic content of the signal (think of the doppler effect on a small, electrical-based scale).
The affected copy (or copies) of the signal is then mixed back with the direct signal, thus giving the effect of a chorus (multiple) voices together, hence the name.
The interaction between the direct signal and the copies offers a subtle phase-shifting effect with both constructive and destructive interference happening across the frequency spectrum. Of course, the “subtlety” can be made obnoxious by cranking the chorus's rate and/or depth controls.
The Boss CE-2W Waza Craft is a simple chorus pedal with rate and depth controls.
The Boss CE-2W is featured in My New Microphone's Top 11 Best Chorus Pedals For Guitar & Bass.
To learn more about chorus pedals, check out My New Microphone's article What Are Chorus Pedals (Guitar/Bass FX) & How Do They Work?
Flanger Pedals
Flanger pedals are quite similar to chorus pedals. We'll often see both effects together in a single pedal.
The famed TC Electronic Stereo Chorus+ is one example of such a chorus/flanger pedal.
The TC Electronic SCF Chorus+ is featured in My New Microphone's Top 11 Best Chorus Pedals For Guitar & Bass.
TC Electronic
TC Electronic is featured in My New Microphone's Top 11 Best Guitar/Bass Effects Pedal Brands To Know & Use.
The flanger effect begins, again, by producing a copy of the direct signal.
This copy is then delayed by a short period (shorter than chorus). An LFO is used to modulate the delay time.
The direct and effected signals are then mixed together at the output.
Since the two signals are identical and only phase-shifted, there will be both constructive interference (peaks) and destructive interference (notches) in the output signal. The series of notches produced will produce a sort of comb-filtering effect that, when modulated to “move” via the LFO, produces what is known as flanger.
Note that flangers have shorter delay times (faster phase-shifting), so their notches will typically be in the higher frequencies. Choruses have longer delay times (slower phase-shifting), so their notches will typically be in the lower frequencies.
The Boss BF-3 is yet another great Boss pedal. The knobs of the BF-3 allow us to control resonance (automatically or manually), the depth of the flanger, the rate of the flanger, and the pedal's mode.
The Boss BF-3 is featured in My New Microphone's Top 11 Best Flanger Pedals For Guitar & Bass.
Note that phaser, though closely related to flanger and chorus, does not use delay. Rather it uses special filters known as all-pass filters, which pass all frequencies at equal amplitude but alter the phase of certain frequencies, the setpoints of which can be controlled via an LFO.
In other words, we could argue that phaser pedals utilize EQ rather than delay circuits to achieve their modulation effect.
To learn more about flanger pedals, check out my article What Are Flanger Pedals (Guitar/Bass FX) & How Do They Work?
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Related Questions
What pedals should every guitarist have? Every guitarist is different and would benefit from different pedals (if at all). There are no particular “must-have” pedals for guitarists. That being said, common pedals to consider include tuners, boosts/preamps, overdrive or distortions, choruses, delays, reverbs and wah pedals.
How many guitar pedals is too many? The number of pedals in an acceptable-sounding rig can be limited by the amount of tone degradation, ergonomics, physical space, price of equipment, cables, the order of pedals in the system and the type of pedals in the system. It also depends on the subjective end goal of the guitarist’s sound.
Related article: How Many Guitar Effect Pedals Is Too Many?
Choosing the right effects pedals for your applications and budget can be a challenging task. For this reason, I've created My New Microphone's Comprehensive Effects Pedal Buyer's Guide. Check it out for help in determining your next pedal/stompbox purchase.
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