Guitar effects change the sound of an electric guitar before it reaches the amplifier or recording system. They can add distortion, echo, reverb, change the pitch, and reshape the sound in much more unusual ways.
So when did guitar effects appear, which one came first? What types are there, and how do they differ? Let’s find out.
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A Brief History of Guitar Effects
The origins of guitar effects can be traced back to the 1940s when musicians began experimenting with different ways to alter their guitar sounds.
Early Effects: 1940s-1960s
The early effects were primarily based on vacuum tube technology, which was also used in amplifiers and radios at the time.
One of the earliest guitar effects was the DeArmond Tremolo Control, introduced around 1946. It changed the volume of the guitar signal in a steady pulse, creating tremolo. The device was unusual even by today’s standards: a small motor moved a container of conductive liquid inside the unit.
Tremolo later became a common built-in effect in guitar amplifiers. It was initially built into tube amplifiers, such as the Fender Tremolux and the Vox AC15.
The Maestro Fuzz-Tone, released in 1962, was one of the earliest fuzz pedals, but it didn’t attract much attention at first. That changed in 1965, when Keith Richards used it for the main guitar riff on the Rolling Stones‘ (I Can’t Get No) Satisfaction. The song made the fuzz sound known to a much wider audience and sent demand for the pedal through the roof.
The Pedal Boom: 1970s-1980s
By the end of the 1960s, guitarists were already using fuzz, wah, echo, and other effects on major rock records. At the same time, transistor circuits made effects smaller and easier to build as pedals. In the 1970s, many new pedals appeared, and some of them became classics.
One of the most iconic pedals from this time was the Electro-Harmonix Big Muff Pi. Released at the end of the 1960s, it became famous in the 1970s for its thick distortion and long sustain. Big Muff Pi helped define the sound of guitarists like David Gilmour, Billy Corgan, and J Mascis.
During this time, companies such as MXR, Boss, and Ibanez introduced many classic effects.
MXR released the Phase 90 in 1974. It became one of the best-known phaser pedals and was used by Eddie Van Halen.
BOSS introduced its compact pedal line in 1977. In 1978, the company released the DS-1 Distortion. The familiar BOSS metal pedal design became a standard that is still used today.
At the end of the 1970s, Ibanez released the Tube Screamer. It had a smoother overdrive sound than many distortion pedals. Guitarists used it both as an overdrive and to push an amplifier into more distortion. It became one of the pedals many guitarists copied, modified, and built their sound around.
In the 1980s, digital effects started to spread. Digital delay gave players cleaner and more controllable repeats than tape echo. Rack processors could combine several effects and save different settings as presets. These systems became especially popular in studios and large touring rigs.
Types of Guitar Effects
The range of guitar effects is huge, and even more variations of them. Some are simple and change only one part of the sound, while others combine several effects in one pedal or processor.
Most effects can be divided into several main types by what they do to the signal:
- Gain and distortion effects – overdrive, distortion, and fuzz
- Dynamic effects – compression, boost, and noise reduction
- Modulation effects – tremolo, vibrato, chorus, phaser, flanger, and rotary effects
- Time-based effects – delay, echo, and reverb
- Filter and EQ effects – wah, envelope filters, and equalizers
- Pitch effects – octave, pitch shifting, and harmonizing
Below, we look at the main guitar effects, how they work, and how they change the sound.
Tremolo
Tremolo creates a pulsing sound by changing the volume of the guitar signal at a steady rate. The pitch of the note stays the same, while the sound becomes louder and quieter. Depending on the settings, tremolo can sound smooth and gentle or sharp and choppy.
Most tremolo effects have two main controls. Depth or Intensity sets how much the volume changes. Speed or Rate sets how fast the pulse repeats.
In technical terms, tremolo is a form of amplitude modulation, and there are several ways to create it. Some circuits use a field-effect transistor, or FET, to control the signal level. Others use an optical system with a small light source and a photocell or light-dependent resistor (LDR).
As the light becomes brighter and darker, the resistance changes, causing the volume of the guitar signal to rise and fall. Some tube amplifiers create tremolo by changing the bias in part of the amplifier circuit.
Tremolo is often confused with vibrato, but they work differently: tremolo changes volume, while vibrato changes pitch.
This is why the term tremolo arm can be misleading. On guitars such as the Stratocaster, the arm changes the tension of the strings and therefore changes their pitch.
Vibrato
Vibrato changes the pitch of the signal instead of its volume. The pitch moves slightly above and below the original note, creating a wavering sound.
Like tremolo, vibrato usually has controls for speed and depth. Speed or Rate controls how quickly the pitch moves up and down. Depth controls how far the pitch moves from the original note.
Electronic vibrato circuits create these small pitch changes continuously while the note is sounding. The result can be very subtle, similar to the natural vibrato made with the fretting hand, or much stronger and more obvious.
This is different from tremolo, where the pitch stays the same and only the volume changes.
Reverb
Reverb is made from many reflections of a sound arriving very close together. In a room, these reflections come from walls, floors, ceilings, and other surfaces. A reverb pedal creates a similar effect electronically or mechanically.
One of the classic guitar effects is spring reverb. Inside a spring reverb pedal are one or more metal springs. A transducer at one end turns the electrical guitar signal into vibrations and sends them through the springs.
The vibrations travel back and forth through the springs and create many small reflections. A second transducer at the other end turns these vibrations back into an electrical signal. This signal is then mixed with the original guitar sound.
The Mix or Depth control determines how much reverb is added. A small amount gives the guitar a little more space and depth. Higher settings make the effect much more obvious and can create a long, “wet” sound.
Spring reverb has its own special character because the springs themselves are part of the effect. If an amplifier with spring reverb is hit or moved suddenly, the springs can shake and produce the familiar loud crashing sound.
Modern digital reverb creates the reflections electronically, so no physical springs are needed. Digital effects can also imitate different spaces and different types of reverb.
Wah-Wah
The wah-wah pedal is a filter controlled by your foot. Moving the pedal changes which frequencies are emphasized, producing the familiar “wah” sound.
With the pedal in one position, lower frequencies may be stronger. As you move it forward, the filter moves through the frequency range and higher frequencies become more noticeable. Moving the pedal back and forth while playing creates the characteristic wah-wah effect.
The speed and timing of the foot movement have a big effect on the sound. A slow movement produces a smooth sweep, while faster movement can make the wah part of the rhythm itself.
The wah became especially popular in rock, funk, and soul. Famous examples include Eric Clapton on Cream’s “White Room“, Jimi Hendrix on “Voodoo Child (Slight Return)“, and the guitar part in the Temptations’ “Papa Was a Rollin’ Stone“. The guitarist on that recording was Melvin M. Ragin, better known as Wah Wah Watson.
Distortion, Overdrive, Fuzz
Overdrive, distortion, and fuzz all change the shape of the guitar signal by clipping it. In simple terms, part of the waveform is cut off instead of being reproduced cleanly. The more the signal is clipped, the more distorted the sound becomes.
The three effects use this idea in different ways.
Overdrive is usually the mildest. It is often used to reproduce the sound of a tube amplifier being pushed hard. The result keeps much of the natural character of the guitar but adds grit, compression, and sustain.
Distortion uses stronger clipping. The sound becomes more heavily changed and usually stays distorted even when the player picks more softly. Depending on the circuit, it can sound smooth and controlled or much more aggressive.
Fuzz pushes the signal even further. Heavy clipping changes the waveform so much that the sound can become thick, buzzing, rough, or almost broken. Some fuzz pedals produce long, smooth sustain, while others create a gated sound where the note seems to cut off suddenly.
These effects are most often controlled with a Gain, Drive, Distortion, or Fuzz knob. This determines how strongly the signal is clipped. A Level or Volume control sets the output level, and many pedals also have a Tone control for adjusting the balance of high and low frequencies.
Distortion does not have to come from a pedal. A tube amplifier can also produce natural overdrive when its gain or volume stages are driven hard. For many guitarists, this amplifier distortion is an important part of the sound, while pedals are used to add more gain or change its character.
Echo
Echo repeats the original guitar sound after a short delay. Depending on the settings, you may hear a single repeat or a whole series of echoes that gradually fade away.
One of the classic ways to create echo is tape echo. These devices use a loop of magnetic tape, a recording head, and one or more playback heads. The recording head puts the guitar signal onto the tape. As the tape moves forward, the playback head reads the recorded signal a moment later, creating the first echo.
Part of that delayed signal can then be sent back to the recording head. This is called feedback, and it creates more repeats. The more signal is fed back, the more echoes you hear before they fade away.
Some tape echo machines have several playback heads. Because each head is a different distance from the recording head, each one produces a different delay time. The delay can also be changed by adjusting the tape speed. Faster tape gives a shorter delay, while slower tape creates a longer one.
Very short delay times can make the guitar sound thicker or give it a sense of space. With a longer delay, the repeats become clearly separated from the original note.
Tape echo machines need regular maintenance. The heads must be cleaned, and the tape loop eventually needs to be replaced as it wears out. Well-known manufacturers included Dynacord and Roland. Roland’s Space Echo series became especially famous among guitarists and recording engineers.
Not every early echo device used tape. Some designs used magnetic drums or discs instead. Modern digital delay and echo pedals create the repeats electronically, so they do not need moving tape, heads, or drums.
Compressor
A guitar can produce a wide range of volume levels. A lightly picked note may be very quiet, while a hard-strummed chord can be much louder. These differences can become especially noticeable when recording or when several effects are used together.
A compressor reduces the difference between the loudest and quietest parts of the signal. When the signal becomes too loud, the compressor reduces its level. Quieter parts are affected less, so the overall sound becomes more even.
After the loud peaks have been reduced, the output level can be raised. This makes quieter details easier to hear without making the loudest notes too strong.
Compression can also add the feeling of longer sustain. As a note begins to fade, the difference between the beginning and the end of the note becomes smaller, so the sound remains noticeable for longer.
A properly adjusted compressor can make the guitar sound smoother and more consistent with little or no added distortion. Too much compression, however, can remove some of the natural dynamics from your playing. It can also make background noise more noticeable.
Tone Booster
A tone booster increases selected frequencies in the guitar signal and changes the balance of the sound. Some boosters emphasize the bass, while others increase the treble or a wider range of frequencies.
A booster can work on a fairly narrow part of the frequency range, making one area of the guitar sound stand out more. Other designs boost everything above or below a selected frequency.
A treble booster, for example, emphasizes the upper frequencies and can make the guitar sound brighter and more aggressive. A bass booster does the opposite, adding more weight to the lower frequencies.
Some boosters mainly change selected frequencies, while others also raise the overall signal level. A stronger signal can then drive an amplifier or another effect harder, adding more gain or changing the character of the sound.
Talk Box
The Talk Box, sometimes called a “Voice Box”, lets the guitarist shape the guitar sound with the mouth.
The guitar signal is sent to a speaker driver. Instead of sending the sound directly into the room, the driver sends it through a plastic tube. The other end of the tube is placed next to the player’s mouth.
The guitarist changes the shape of the mouth just as when speaking. These movements change the sound coming from the tube, making the guitar form vowel-like sounds or even seem to “talk”.
A microphone placed in front of the player’s mouth picks up the modified sound and sends it through the PA system.
Different Talk Box designs handle the signal in different ways. Some have a built-in amplifier, while others are connected to an external guitar amp. The basic process is the same: the guitar creates the sound, the tube carries it to the mouth, and the mouth shapes it.
Envelope Modifiers
The volume of a guitar note does not stay the same from beginning to end. It rises quickly when the string is picked and then gradually falls as the note fades. This changing shape of the sound is called its Envelope.
An Envelope filter uses these changes in volume to control a filter automatically. An envelope follower tracks the level of the guitar signal and uses it to move the filter.
This means the effect reacts directly to how hard you play. Pick or strum harder and the filter moves farther. Play more softly and the effect becomes less pronounced. As the note fades, the filter moves back again.
The result can sound similar to a wah-wah pedal, but there is no foot pedal to move. The filter follows the dynamics of your playing automatically and can produce the familiar “wah”, “wow” or “quack” sound often heard in funk.
Well-known examples include the Seamoon Funk Machine and the Mu-Tron III. The Mu-Tron III became one of the best-known envelope filters of the 1970s and was used by musicians including Stevie Wonder.
Noise Gates
Unwanted noise can come from the guitar, amplifier, cables, or other effects in the signal chain. A noise gate helps reduce this noise by cutting the signal when its level falls below a set point.
The main control is usually called Threshold. It sets the level at which the gate opens and closes. When the guitar signal is louder than the threshold, it passes through normally. When the signal falls below it, the gate reduces or blocks the sound.
The threshold has to be set carefully. If it is too low, some background noise will still pass through. If it is too high, the gate may cut off quiet notes or shorten their sustain.
Some noise gates also have controls for how quickly the gate opens or closes. A fast setting can remove noise very sharply, while a slower setting gives the end of a note more time to fade naturally..
Pre Amplifiers
A preamplifier, or preamp, boosts and shapes the guitar signal before it reaches the main amplifier.
A preamp can increase the signal level, change the tone with EQ, and in some designs add overdrive or distortion. It can also send a stronger signal into the input of a guitar amp, causing the amp itself to distort more.
This is different from a fuzz pedal. A fuzz circuit creates its own heavily clipped sound, while a preamp usually works by amplifying and shaping the original guitar signal.
Preamps are not always separate pedals or boxes. Many guitars with active electronics have a small preamp built directly into the instrument. These circuits can provide a stronger output and give the player more control over bass, treble, or other parts of the tone.
Leslies
The Leslie speaker was originally designed for organs, especially the Hammond organ, but guitarists also began using it for its deep, swirling sound.
A classic Leslie does not simply rotate the speaker itself. It uses a rotating horn for the higher frequencies and, in many models, a rotating drum or rotor for the lower frequencies.
As these parts rotate, the sound moves toward and away from the listener. This creates small changes in pitch through the Doppler effect. At the same time, the volume and tone also change as the sound moves around the room. All of these changes combine to create the characteristic Leslie sound.
Phase also plays a part in what we hear. When similar sound waves meet at different points in their cycles, some frequencies become stronger while others are partly cancelled. Because the Leslie is constantly moving the sound around, these relationships keep changing.
Most Leslie speakers have at least two speeds. The slower setting creates a gentle movement, while the faster setting produces a much stronger swirling effect.
Although the Leslie is best known for its use with the Hammond organ, it has also been used with electric guitar to create a wide, moving sound.
Phaser
A phaser creates a sweeping sound by changing the phase of different parts of the guitar signal.
Inside the effect, the signal passes through several all-pass filter stages. These filters do not simply boost or cut frequencies like a normal EQ. Instead, they change the timing, or phase, of different frequencies.
The processed signal is then mixed with the original signal. At some frequencies, the two signals reinforce each other. At others, they partly cancel each other out. This creates a series of moving peaks and dips in the sound.
A low-frequency oscillator, or LFO, moves these phase changes up and down through the frequency range. The Speed or Rate control sets how fast this sweep moves.
Some phasers also have a Feedback or Resonance control. This sends part of the processed signal back through the circuit, making the phasing effect stronger and more noticeable.
The result can range from a soft, slow movement to the stronger “whooshing” sound often associated with classic phaser effects.
Flanger
Flanging began as a studio effect using two tape machines playing the same recording at almost the same time. By slightly changing the speed of one machine, engineers created a tiny delay between the two signals.
When the two signals were mixed together, some frequencies reinforced each other while others cancelled out. As the delay changed, these points moved through the frequency range, creating the sweeping flanger sound.
An electronic flanger creates the same basic effect with a very short delay instead of two tape machines. The delay time is continuously moved back and forth, usually by an LFO.
This produces a series of moving peaks and notches in the sound. The effect can be subtle, but at stronger settings it creates the familiar metallic or “jet-like” sweep.
Many flangers also use Feedback, which sends part of the delayed signal back into the effect. More feedback makes the sweep sharper and more dramatic.
A flanger and a phaser can sound similar, but they work differently. A phaser changes phase with filter stages, while a flanger uses a short changing delay.
Ring Modulator
A ring modulator combines the guitar signal with a second signal produced by an oscillator. Instead of simply adding the two sounds together, it creates new frequencies based on the sum and difference between them.
This is why a ring modulator sounds so different from normal distortion or modulation effects. It can produce metallic, bell-like, dissonant, or “spacey” sounds that may have very little in common with the original guitar tone.
The sound changes depending on the oscillator frequency. At some settings, the new tones can still follow the notes you play. At others, the result becomes much stranger and more dissonant.
The Mix or Intensity control determines how much of the processed sound is added to the original guitar signal. With a small amount, the effect can add unusual harmonics. At stronger settings, the ring-modulated sound can completely dominate the original note.
Octave Dividers and Octave Multipliers
An octave divider adds a note one or more octaves below the note played on the guitar. This can make a single guitar line sound much fuller, almost as if a bass guitar were following the same notes.
Traditional analog octave dividers work by detecting the pitch of the incoming note and electronically dividing its frequency. For example, dividing the frequency by two produces a note one octave lower.
Older octave effects do not always track the guitar perfectly. Strong harmonics can sometimes confuse the circuit, causing it to follow the wrong part of the signal. The added octave can also sound rough or distorted.
These effects are usually easier to use with single-note lines. With chords, an older monophonic octave divider may have trouble deciding which note to follow, and the result can become unclear or unstable.
An octave multiplier works in the opposite direction and adds a note above the original pitch. A higher octave can make the guitar sound brighter and give a single-note line a stronger, more noticeable edge.
Modern polyphonic octave pedals work differently from many older analog designs. They can track several notes at the same time, which means they can also work with chords and more complex playing.
Other Guitar Sound Devices
There are also guitar devices that do more than one thing at a time. Some combine several effects in one system, while others change the way the guitar creates or controls sound.
Consoles
In the late 1960s and 1970s, some manufacturers began building large guitar processors that combined several effects in one device. These devices could combine fuzz, filters, modulation, octave, and other effects.
One of the most unusual examples was the EMS Synthi Hi-Fli, introduced in the early 1970s. It was designed for guitar and used two foot pedals together with a large control panel. It included fuzz, octave effects, ring modulation, phasing, vibrato, wah-like filters, and frequency shifting. The pedals could be assigned to different controls, allowing the guitarist to change the sound while playing.
Another example is the Maestro G-2 Rhythm ‘N Sound for Guitar. Introduced in the late 1960s, it combined several effects and even included percussion sounds that reacted to the guitar signal.
These large systems were an early version of an idea that later became very popular: putting several effects together and controlling them from one place.
Gizmotron
The Gizmotron, or Gizmo, was invented by Lol Creme and Kevin Godley of 10cc in the 1970s. It attached near the bridge of an electric guitar and used small motor-driven wheels to rub against the strings.
When the player pressed one of the controls, a wheel touched the corresponding string and kept it vibrating. Instead of the normal attack of a picked note, the guitar could produce a long, bowed sound similar to a cello or other string instrument.
The guitarist could still pick or strum normally, so the Gizmotron sound could be mixed with regular guitar playing. It could also sustain several strings at once, making it possible to create string-like chords and layers from a guitar.
Godley and Creme used the Gizmotron while making the album Consequences, which began partly as a demonstration of what the invention could do. It was also used on their later album “L.“
Guitar Synthesizer
A guitar synthesizer allows a guitarist to control synthesizer sounds from a guitar instead of a keyboard. The idea sounds simple, but early systems had a difficult job: they had to recognize the pitch and volume of a vibrating guitar string and turn that information into signals a synthesizer could use.
This was especially difficult with early monophonic systems, which could follow only one note at a time. They worked best with single-note playing and often had trouble with chords. Polyphonic systems were designed to process several strings or notes separately, making chords and more complex playing possible.
Different manufacturers tried different ways to solve the problem. Some guitars had special electronics built into the instrument, while others used a separate pickup and an interface between the guitar and synthesizer.
One early example was the 360 Systems Slave Driver. It used a pitch-to-voltage converter to turn the pitch of the guitar note into a control voltage for an analog synthesizer. An envelope follower tracked the level of the guitar signal and provided information about how loudly the note was played.
Walter Sear also experimented with guitar-controlled synthesizers in the 1970s. One of his systems connected a transparent Dan Armstrong guitar to a Moog synthesizer, allowing a guitarist to control synthesizer sounds directly from the instrument.
Another important early system was the ARP Avatar, released in 1977. A special pickup mounted on the guitar sent the string signal to the synthesizer, where it was converted into control information. The Avatar was monophonic, so it worked with one note at a time. Its analog synthesizer section included oscillators, filters, and envelope controls similar to those found on other ARP synthesizers. Pete Townshend was one of the musicians who experimented with it.
The Hagstrom Patch 2000 took a very different approach. The guitar’s neck was specially wired so that touching a string to a fret created an electrical contact. The system could then determine which note was being fretted and send this information to a synthesizer. The guitar could be used as a normal electric guitar, as a synthesizer controller, or both at the same time.
Modern guitar synthesizers are much faster and more accurate than these early designs. They can track several strings at once, follow bends and playing dynamics more closely, and produce a wide range of sounds while the guitarist continues to play in a familiar way.
Modern Guitar Effects and Software
The biggest changes in guitar effects in recent years have come from digital modeling, amp capture, impulse responses, and software. Modern systems can reproduce complete amp and cabinet setups, copy the response of real amplifiers and pedals, and save complex signal chains for later use.
These technologies are now used both in hardware processors and computer software, and the same guitar sound can often be moved between recording, practice, and live setups without rebuilding the entire rig.
Digital Modeling and Multi-Effects
In 1996, Line 6 released the AxSys 212, one of the first guitar amps built around digital models of different amplifiers and cabinets. Two years later, the POD put the same idea into a small desktop processor.
Modern processors can combine many effects in one signal chain. Distortion, modulation, pitch effects, delay, reverb, EQ, and other processing can be arranged in almost any order. Complete setups can then be saved as presets and recalled without adjusting every effect again.
Some processors also include amp and cabinet modeling. Instead of using a real amplifier and speaker cabinet, digital modeling recreates their sound and response electronically. Modern systems can model different amplifier channels, gain settings, speaker cabinets, microphones, and even the position of the microphone in front of the speaker.
The Fractal Audio Axe-Fx became popular in studio and touring rigs for its deep amp controls and flexible routing. The Line 6 Helix put amp modeling, effects, and complex signal chains into a floor processor designed for direct foot control on stage.
Amp Profiling, Capture, and IRs
A more recent development is amp profiling and capture. Traditional modeling starts with a digital model created by the manufacturer. Profiling and capture take a different approach: the system analyzes a real amplifier, pedal, or complete setup and creates a digital version of its response.
In 2011, Kemper released the Profiler, a device that captures a real amplifier’s sound and response as a digital profile. The profile can then be used later without the original amplifier connected.
The Neural DSP Quad Cortex and IK Multimedia TONEX use their own capture systems for amplifiers and pedals. These captures can be saved, shared, and loaded again when needed.
Another important part of modern digital guitar rigs is the impulse response, usually shortened to IR. An IR captures the response of a speaker cabinet and microphone setup. It does not reproduce the entire amplifier. Instead, it recreates the part of the sound created by the cabinet, speaker, microphone, and their interaction.
For example, the same modeled amplifier can sound very different when used with different IRs. Changing the virtual cabinet, speaker, microphone, or microphone position can have a major effect on the final guitar tone.
IRs are used in hardware modelers, amp simulators, recording software, and some modern pedals. They are especially useful for recording or sending a guitar signal directly to a PA without using a real speaker cabinet and microphone.
Software Guitar Effects
Guitar effects began moving into computers long before the current generation of modelers. VST, introduced by Steinberg in the 1990s, made it possible to run audio effects as plugins inside recording software. Guitar amp and effects plugins became much more popular in the following years as computers became faster and recording at home became easier.
VST is only one plugin format. Audio Units (AU) are widely used on macOS, while AAX is the main format used by Pro Tools. The basic purpose is to make the guitar signal processable inside the computer.
Modern guitar software can recreate an entire signal chain. A single program may include amplifiers, cabinets, microphones, distortion, modulation, delay, reverb, EQ, pitch effects, and routing.
Some of the best-known guitar programs include IK Multimedia AmpliTube, Native Instruments Guitar Rig, Positive Grid BIAS FX, and Scuffham Amps S-Gear. Neural DSP also offers a large range of guitar plugins, many built around particular amplifiers, sounds, or artists.
One reason software effects have become much more practical is the improvement in audio interfaces and computer latency. The delay between playing a note and hearing the processed sound can now be low enough for normal playing and recording on a properly configured system.
Software also makes DI recording and reamping much easier. A clean guitar signal can be recorded first, while the amplifier, cabinet, and effects are chosen later. If the distortion or amp sound does not work in the mix, the original performance can be processed again without recording the guitar part from scratch.
Modern guitar effects are therefore no longer tied to one type of equipment. A rig can use a real fuzz pedal, a captured amplifier, an IR cabinet, digital delay, and software processing in the same setup.
How to Connect Guitar Effects
The order in which guitar pedals are connected is called the signal chain. Changing that order can change the sound quite a lot, especially when distortion, modulation, delay, and reverb are used together.
There are many ways to arrange guitar effects, but one of the most common looks like this:
Guitar -> Tuner -> Wah / Filter -> Compressor -> Pitch Effects -> Overdrive/ Distortion/ Fuzz -> Modulation -> Delay -> Reverb -> Amplifier
A tuner is usually placed near the beginning so it receives a clean guitar signal. Wah and envelope filters also work well early in the chain because they react directly to the guitar signal and the way you play.
A compressor is often placed before distortion and overdrive. It evens out the signal before it reaches the gain pedals. Pitch effects, such as octave and pitch shifting, are also usually placed early because they track notes more accurately before the signal becomes heavily distorted.
Overdrive, distortion, and fuzz normally come before modulation and time-based effects. This lets chorus, phaser, flanger, delay, and reverb work on the distorted sound rather than being distorted themselves.
There are exceptions. Some vintage-style fuzz pedals work best directly after the guitar because their circuits react strongly to the guitar pickups. Placing a buffer, tuner, or another pedal in front of them can change the way they sound and respond.
Modulation effects such as chorus, phaser, and flanger are often placed after distortion. Moving them before distortion gives a different result, so this is one part of the chain where experimenting with the order can be especially useful.
Delay and reverb are usually placed near the end. Delay repeats everything that comes before it, while reverb adds space to the final sound. If they are placed before heavy distortion, their repeats and reverb tails are distorted too, which can make the sound much less clear.
Many amplifiers also have an effects loop between the preamp and power amp. This is especially useful when the amplifier itself provides most of the distortion. Delay, reverb, and sometimes modulation can be connected through the effects loop so they come after the amp’s preamp distortion.
The basic order is only a starting point. Moving a wah after distortion, putting a phaser before overdrive, or running delay into distortion can all produce very different sounds.
Pedal order is part of the effect itself, so the best chain depends on the sound you want.