Learn the history of effect pedals and see how technology now allows you to obtain the same sounds using virtual pedalboards with digital plugins

Over the years, musical instruments have been modified to better meet the sound needs of musicians as well as the musical demands of each era.

With technological advancement, new instruments were created while other ways of manipulating the sound were improved, creating new possibilities for guitarists and other instrumentalists.

That is the case with effect pedals.

We can define an effect pedal as a portable device, actionable with the feet, capable of altering the sound signal between the guitar and the amplifier.

Nowadays, effect pedals are considered more than just accessories to produce timbre changes in an instrument. Many musicians even work with this equipment as if they were musical instruments, obtaining unique and innovative sounds.

In this article, we’ll talk about the evolution of effect pedals from the mid-20th century to the present day, when digital technology has converted transistorized circuits into plugins that can be modified by musicians themselves to build virtual pedalboards.

At the end of the text, we describe the most iconic pedals in music history and indicate a plugin to digitally emulate each effect. All of them available for download from the MOD Devices plugin gallery.

Turn up the volume and let’s go!

The prehistory of pedals

Before the first pedals were developed, effects used to be incorporated into the amplifiers. 

From the 1930s, the popularization of tube models contributed to the emergence of the first experiences with saturation, since these devices still did not support high volumes at that time.

In the 1940s, Leo Fender’s work took amplifier technology a step further, adding potentiometers for bass, mid, treble and presence control.

Another invention that went hand in hand with the evolution of the amplifier and contributed to the construction of the guitar’s timbre was the echo effect.

The Echosonic was the first amplifier developed with this technology, and its main characteristic was to generate a delay in electronic impulses.

In 1959, a new leap came with the creation of Echoplex. Based on the tape recorders, this device had characteristics similar to those presented in the Echosonic amplifier.

However, being an independent device, it allowed the guitarist to connect it to any other brand of amplifier that was available on the market.

This device has become a sound reference to this type of effect, and is still digitally simulated by several companies that manufacture delay pedals.

Later, other effects like tremolo and reverb were invented, became popular and were also inserted in the amplifiers.

The first effects pedals

With the popularization of the transistor in the late 1950s other innovations emerged, the transistorized amplifier among them.

Because it didn’t use valves, this equipment had a totally pure sound without distortion even when operating at a very high volume.

This historic moment was characterized by experimentation with new timbres and sounds, even trying to recreate the distortion of the old tube amps that was impossible to obtain using its transistorized “cousins”.

The distortion, in addition to modifying the sound, gave greater amplitude to the guitar sound and helped the player to achieve greater sustain.

The discovery of this effect by a new generation of guitarists spurred manufacturers like Marshall, Fender and Vox to develop what we know today as an effect pedal.

Over time, musicians with knowledge of electronics began to develop their own pedal designs.

With the emergence of new effects, each musical style became accustomed and became familiar with these devices that musicians sought to build their musical identity.

The diverse sounds generated by those pedals contributed to the emergence of several strands of the old rock’n’roll music, making that musical style to branch out partly due to the use of different effect pedals.

Among these ramifications we can mention: Metal and Grunge using distortion; Progressive Rock and Psychedelic Rock with echo and chorus; Punk Rock with fuzz; Pop Rock, Hard Rock and Glam Rock with overdrive, among others.

Types of effect pedals

We can classify the main effect pedals in six groups, according to their common characteristics:

Gain pedals: Within rock and heavy metal, the gain pedals are the most famous and used. These pedals transmit the signal through a transistor or diode to reproduce the sound of a tube amplifier. Examples: fuzz, distortion and overdrive.

Modulation pedals: Essential for guitarists who want to go beyond gain, they can fill the instrument’s sound with different and more complex effects. They were created to reproduce characteristics of the original rotating speaker, initially inspired by the Leslie Cabinet that accompanied the Hammond B3 organ. Examples: chorus, flanger, phaser and vibrato.

Timing pedals: As the name implies, timer pedals are based on time changes caused by the signal. They can offer from a few extra notes to drastic changes in the sound, creating different environments. Examples: delay, reverb and looper.

Pitch Pedals:  are the ones that add or change notes in the guitar signal. It is like changing the tuning of your instrument. The result is very easy to identify, since the sound is somewhat digitized and sometimes mixes both the original and the altered sound. Examples: arpeggiator, pitch shifter, harmonizer and tuner.

Filter/Tone pedals: The filter and tone pedals are those that modify the volumes of specific frequencies in some way. They could be placed in the shade category, but it is interesting to see them on another “shelf”. These pedals can serve as stationary or dynamic equalizers. The proposal may be to ignore, reduce or accentuate different frequencies in the signal, resulting in unique sounds. Examples: equalizer, wah-wah, envelope filter and talk box.

Volume pedals: As the name implies, they are used to change the volume of the guitar signal. For that reason, they are usually at the end of the chain of pedals, before just the timer pedals, so that the signal arrives complete before the volume reduction and the effects of time. Examples: boost and tremolo.

Classic pedals and digital plugins

Next, we will briefly describe some of the most important effect pedals and indicate digital plugins, which represent the state of the art in the evolution of these effects.

The plugins indicated in this article were all developed in open code and can be used to assemble virtual cranks for use in the innovative digital stompboxes produced by MOD Devices.


One of the most “primitive” pedals, fuzz is also one of the most popular. Its sound is based on the saturation of old tube amplifiers. It is like a distortion, only less controlled and more full-bodied, even a little “dirty”.

Its digital soulmate is GxFuzzMaster, modeled after the Vintage Fuzz Master, a really wild fuzz that gives back to the fuzz sound that was heard in the most insane Jimi Hendrix performances, or psychedelic noise freak outs of the 60’s and 70’s. All the madness of a vintage fuzz without the hassle of carrying a stack with you.


The most famous effect of rock and, perhaps, of all music. The dynamics of the distortion pedal is similar to that of the fuzz: recreating the sound of a high-gain tube amplifier. The difference is that the distortion ends up being a little more malleable and, in a way, versatile, with possibilities of control and tone that go beyond. It’s like the fuzz after going to the barbershop.

The MOD team modeled the DS1 plugin after the legendary BOSS DS-1, a distortion pedal mainly used for guitar. Simply put, the DS1 distortion pedal is a modern classic. It was first produced in 1978 and is still widely popular. No wonder it was part of pedalboards from great names such as Kurt Cobain, Joe Satriani, Steve Vai and Josh Klinghoffer. The DS1 features three knobs which can take the sound in a variety of different directions.


The dynamics of overdrive is similar to that of distortion and fuzz, but the sound acquired is a little closer to what you actually get from tube amplifiers at really high volume. The focus is on saturation, which leaves the sound not so focused on weight, but on warmer tones.

The GxTubeScreamer is an analog distortion emulation of a real classic: the Ibanez TS-9, first released in 1982. It is one of the most successful, widely copied and “modded” overdrive pedals in the history of the electric guitar. The pedal mimics the sound of a vintage tube amplifier, and has a characteristic mid-boosted tone which is popular amongst blues and rock players. 


One of the most popular modulation pedals, the chorus has a typically underwater sound. For this, the pedal doubles the guitar signal and leaves the “bent” slightly out of time, crossing with the original. It is possible to regulate in very subtle ways, as if you were playing with two separate amplifiers, or very drastic, as if you were two guitarists playing together.

The CR-1 Chorus is intended to emulate a classic, analogue and vintage sound. Ranging from subtle modulation effects to bright coloration, the CR-1 will add a retro feel and enhance all of your instruments.


The flanger offers a kind of distortion in the phase and in the tone of the guitar signal. The signal is doubled as in chorus, but here, the “fold” starts slower and then accelerates. It is as if it stayed behind, but reached the original signal. 

The MDA ThruZero simulates tape-flanging, where two copies of a signal cancel out completely as the tapes pass each other. It can also be used for other “modulated delay” effects such as phasing and simple chorusing.


The phaser is also based on the duplication of the signal, except that, in this case, the doubled signal has a cycle that enters and leaves the phase of the original. It sounds like a jet plane taking off.

The Phaser II is a modern take on this classic, well-loved effect. Thanks to its two modulation options, you will be able to customize your sound using either a traditional sine-based periodicity or the smoothened fractal oscillation.


As the name already indicates, the vibrato pedal offers the effect of signal vibration. The doubled signal is modulated by tuning, creating this illusion that the guitar lever is used all the time.

The Larynx is a simple, great sounding vibrato effect with a tone control. The Depth knob controls the intensity of the modulation effect and Rate changes the modulation frequency.


The delay pedal doubles the guitar signal and allows you to define how long the “folded” version will be played, as well as how many times it will be played. It serves both to change the sound of what you are playing at that moment and to create a live base, allowing you to do a solo over the top without having a rhythm guitarist behind.

The Scape delay looks like a straightforward delay pedal but there is more than meets the eye. The delayed sounds can be re-tuned with the Tune knob in the settings session. Set it to your standard tuning of 440Hz and hear a normal rhythmical sounding delay. Or use it to achieve some interesting modulated sounds. Each note will be slightly different, further increasing the uniqueness of this effect.


The name “reverb” is a shortened version for “reverberation”, that is, the persistence of a sound after it is produced, according to the environment and the surface it is on. The reverb pedal helps to transport the listener to any location – from a concert hall to a cave. It is one of the most versatile and complete effects that exist.

With the Roomy reverb you can easily add a natural color and liveliness to your sound, mostly if you’re going for a natural, in-person kind of sound. The Decay knob allows you to set the duration of the reverb, the Damping knob allows you to control the high frequencies in the reverb tail, producing a warmer sound with less “edge”, and finally the Mix knob selects the amount of dry and wet signal. 


The looper is like an improvement of the delay, expanding the repetition time of a sound. It is recommended, especially, when the idea is to obtain “eternal repetitions”. Because it is very useful, the looper is almost essential for artists who perform alone or with few instruments.

Developed by the Jesse Chappell, the SooperLooper is a simple, straightforward looping station that can be used to layer some vocal or guitar harmonies. It also comes in a stereo version.


An arpeggiator is a sequencer. A sequencer plays a series of sounds based on a source and parameters set by you, the user/musician. In the case of an arpeggiator pedal, the “source” is whatever you plug into it: guitar, bass guitar, synth, toy, etc. The parameters are the pedal knobs and buttons, controlling things like: pitch, tempo, order, steps, scale, key, etc. 

The MOD Arpeggiator is a classic arpeggiator with some added spice. The plugin is specifically designed for the MOD platform, with a focus on live usage. Besides the standard arpeggiator controls, there is also a special control, called “Octave Mode”. When set to “1 Up / Cycle”, the plugin acts as the typical arpeggiator we all know and love. The other options provide more variations to extend the classic paradigm.

Pitch shifter

Known by its versatility, the pitch shifter can be associated with a wah-wah or volume pedal to accentuate its effect. The idea is similar to that of the arpeggiator, but it can vary between more octaves and add variations in sonority.

The MOD 2Voices is a pitch-shifter featuring two outputs with independent pitch-shift controls. The pitch of the input signal can be shifted anywhere between -12 semitones down, and +24 semitones up. Particularly relevant for low-CPU use cases.


The harmonizer is like a specific pitch shifter variation to create harmonies in your sound. The proposal is to retain the original sound and add the new note, modified, to a specific distance from the original, harmonizing automatically.

The Harmonizer plugin is a (relatively) simple harmonizer that allows you to set the scale to either Major, Minor, or Minor Harmonic, and then shift up a +3rd or +6th, or down a -3rd or -6th in that scale. As with nearly all harmonizers, you will have to play in the correct key (which can also be configured).

Wah-wah e Auto-wah

Basically, wah-wah is a bandpass filter that attenuates low and high frequencies. It’s like having a tone pedal on your foot. They can be activated manually, by a potentiometer that is below the continuous control pedal, or automatically, as soon as you step on the pedal. Also known as an envelope filter, auto-wah uses signal strength to control the frequency sweep. The amount of “wah” is defined by the knob setting.

The Auto-wah available in MOD’s Plugin Gallery is a combination of an envelope follower and a resonant low pass filter. For increasing sound levels, both the frequency and the bandwidth of the filter will increase. The intensity is controlled by ‘Drive’. For a normal wah, you can use an expression pedal to control ‘Frequency’ and set ‘Drive’ to zero.


The idea behind the boost pedal is simply to increase the volume of your guitar at a specific pass. And this is done without creating saturation – so it cannot be placed in the category of gain pedals. However, it is also possible to create and experiment with this pedal, associated with other types of effect pedals – whether to offer some notes higher than others, to press in a rhythmic way or something like that.

The GxBooster is a 2 band boost plugin which allows you to boost the high and the low frequencies independently.


The tremolo pedal reduces and increases the volume of the signal cyclically, from a periodic variation in amplitude. Old amplifiers often have this tremolo function that today is translated into pedals. 

The TAP Tremolo plugin is a great straightforward tremolo with easy controls, suitable for use with any instrument. The Harmless plugin is a waveshapeable harmonic tremolo with a stereo phase control.


The compressor pedal is considered one of the essentials for guitarists who prioritize the clarity of their notes. As the name implies, it is used to compress the signal so that it is neither too high nor too low. The proposal is to level the volume of what is being played. This helps to present a more consistent and well-regulated sound.

The Invada Compressor is a very easy to use, high-quality relaxed compressor that features 6 knobs and a high level of controllability. The ‘Attack’ controls how quickly the compressor starts to act. The ‘Release’ is the period when the compressor gradually stops acting. The Knee controls whether the bend in the response curve between below threshold and above threshold is abrupt (hard) or graduated (soft).  

How can you try all these cool plugins?

All the digital stompboxes made by MOD Devices grant you acces to more than five hundred audio and MIDI plugins in a collection that will never stop growing.

You can choose from all the famous stompboxes, FX, synths, sequencers and amps that made history in music.

In order to further expand your sonic possibilities, there is also a wide range of exotic synths, sequencers and tailored effects for crafting original sounds you’ve never heard before.

With all these variety of digital effects, you can build your own boards and optimize them for any instrument you wish. 

Wanna give them a try?

Visit our website and get to know more about our multipurpose audio devices.