Whether you’re looking to expand the sonic capabilities of your guitar; want a synth but can’t afford one, or trying to kick the synth player out of your band, a synth pedal could be for you!
What are synth pedals and how do they work? A synth pedal is an audio synthesizer in a stompbox format that works with guitar or bass signals rather than MIDI or keyboard triggers. Some use the audio signal to trigger an oscillator; others sample the input and affect it; some use pitch multipliers, but all output a synth-like signal.
Jokes aside, synth pedals can really add a whole new world of creativity to a guitarist or bassist’s playing and writing. By tapping into the vast world of audio synthesis, we open up numerous sonic capabilities that would not be achievable with a guitar (or bass) on its own.
In this article, we’ll discuss synth pedals in much more detail, getting into bass and guitar synths; how audio synthesis and synth pedals 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 synth pedal.
Table Of Contents
- What Is Audio Synthesis?
- Types Of Audio Synthesis
- Monophonic Vs. Polyphonic Synthesizers
- What Is A Synth Pedal?
- Types Of Synth Pedals
- Other Synth Like Effects
- Typical Controls On Synth Pedals
- Tips On Using A Synth Pedal
- Where Should Synth Pedals Go In The Signal Chain?
- MIDI Synth Pedals & MIDI Guitars
- Related Questions
What Is Audio Synthesis?
Synth pedals are often misunderstood. Audio synthesis is a complex topic and there are plenty of different synth types and synth pedal types, which we’ll get to later. To really understand how synth pedals work, it’s critical to understand audio synthesis in general.
Audio/sound synthesis is defined, loosely, as any technique that produces audio (and, thereby, sound if connected to an electro-acoustic transducer like a headphone or loudspeaker) using electronic hardware or software.
In other words, it’s audio the is not previously recorded nor is it sound that can be made by an acoustic sound source (such as a vibrating string, column of air or other object).
Synthesis relies completely on electronic devices producing audio waveforms from scratch.
There are several types of synthesis which we’ll get to shortly.
To better understand audio synthesis, we should understand how synthesizers work. This will also help us to understand synth pedals in this article.
A synthesizer, as we could guess by the above paragraphs, is an electronic instrument that produces audio via one or more forms of synthesis.
Synths come in a variety of synthesis types, shapes and functionalities. They can be used to model the sounds of real-world instruments or to create completely new sounds that are impossible to produce acoustically.
Synthesizers typically generate audio waves with oscillators. These oscillators can be basic waveforms (sine, triangle, square, sawtooth, etc.) or they can be more complex. Synths can also work with samples to create their audio waves.
Once produced, the audio of a synthesizer will often be subjected to a range of components that will further modulate or shape the sound. These components include but are not limited to filters, envelopes and low-frequency oscillators (LFOs) that can alter different parameters of the audio such as frequency response, pitch, and amplitude.
Furthermore, synths can also be processed by effects much like guitars can. Synths can even be run through the same pedals guitar are typically run through.
For more information on running synths through guitar pedals, check out my article Do Guitar Pedals Work With Keyboards & Synthesizers?
Types Of Audio Synthesis
As previously mentioned, there are several types of audio synthesis to be aware of. Note that not all these synth types will show up in guitar and bass synth pedals. However, it’s good to know what is out there and to have an idea of the synth designs we’ll find in our synth pedal(s).
The types of audio synthesis are:
- Subtractive synthesis
- Additive synthesis
- Physical modeling synthesis
- Wavetable synthesis
- Vector synthesis
- Linear arithmetic synthesis
- Phase distortion synthesis
- Frequency modulation synthesis
- Sample-based synthesis
- Granular synthesis
Subtractive synthesis is the most common type of audio synthesis.
It utlizes one or more oscillators to produce an audio signal. This audio signal is then sent through a filter for EQ purposes before it reaches an envelope that controls its ADSR (attack, delay, sustain and release).
Subtractive synthesis, then, has its oscillators create the signal and then the other components subtract what isn’t need from the signal to shape it appropriately.
The idea here is that any timbre can be produced by an osciallator or, if not, then with a combination of oscillators.
By running the oscillators through filters and a specified ADSR envelope, we can effectively subtract from the oscillators what is needed to create a dynamic and interesting sound.
Real instruments have rather complex ADSR/envelope profiles. Subtractive synthesis can recreate many instruments electronically by following the same intital waveform and envelope observed of an instrument in nature.
Additive synthesis goes about things quite differently that subtractive synthesis though not in an exact opposite fashion as the names may suggest.
This type of synthesis constructs the harmonic make up of the signal on a per-frequency basis. In other words, sine waves (which are made of a single frequency) of various amplitudes are produced at specified frequencies to build/synthesize the audio.
The amplitudes of each sine wave vary across time to achieve the “envelope” of the sound.
We can think of additive and subtractive synthesis in the following ways:
- Subtractive synthesis starts with everything the sound requires and pieces are subtracted to get what we need.
- Additive synthesis starts with nothing and everything we need is added.
I’ll add here that additive synthesis is very closely related to resynthesis.
Resynthesis is a process that takes a sampled sound and analyzes it to recreate it synthetically. This recreation is typically done with additive synthesis. The difference between the two is that resynthesis is sample-based while additive synthesis is more so from scratch.
Physical Modeling Synthesis
Physical modeling is a super in-depth form of synthesis that, typically, aims to synthesize the sound of an instrument with utmost precision.
This type of synthesis uses mathematical algorithms to account for every nuance of an intended physical sound source.
With adequate digital signal processing, physical modeling synthesis can effectively take into account all parameter that could alter the timbre and amplitude of the instrument in question.
This type of synthesis is very complex and we don’t see it in synth pedals. Nonetheless, this impressive technology is worth knowing about!
Wavetable synthesis utilizes wavetables as oscillators rather than distinct waveforms.
Wavetables are effectively a continuously variable waveform that morphs from one waveform to another. The instantaneous position of the wavetable will present a certain oscillator waveform and this waveform will change as the table is cycled through.
As the waveform changes, the oscillator will present a different harmonic profile/timbre.
Vector synthesis is very similar to wavetable synthesis in its focus on waveform morphing.
Wavetable synths will have a sort of continuou back and forth between two distinct waveforms.
Vector synthesis will have four distinct waveforms all cross-faded seemlessly together. Each of the four waveforms will have its own corner on a square and we will morph between them by adjusting our point within the square.
This adjusting can be done via a joystick or via controls such as envelopes or LFOs.
Linear Arithmetic Synthesis
Linear arithmetic synthesis is somewhat outdated but was useful when invented.
To save space in the early days of digital synthesis, Roland developed linear arithmetic sysnthesis. This type of synthesis utilized samples of the attack periods of the instruments being synthesized. After the attack was sampled, one or more internally-generated waveforms would complete the decay, sustain and release of the sound.
This type of synthesis worked to varying degrees because much of the timbre we hear from any instrument is based on the attack of the instrument. After the attack, the sound of most insturments will tranform into a relatively simple waveform, easily achieveable via synthesis.
This helped to save memory space in the digital synth and allowed for more instruments to be sampled/synthesized in the Roland D-50 synthesizer (which used this type of synthesis).
Phase Distortion Synthesis
Phase distortion synthesis is the same as subtractive synthesis except for one key difference: the waveform of the oscillator is a continuously variable wavetable rather than a fixed waveform.
Frequency Modulation Synthesis
Frequency modulation (FM) synthesis is a completely different beast that what we’ve discussed thus far.
As the name suggests, FM synths use modulation oscillators to vary the frequency of a carrier wave in order to produce new waveforms and harmonic profiles.
The modulation oscillator must be faster than an LFO (up into the audible range) in order to affect the timbre of the carrier oscillator. At low speeds, the modulator would simply produce a vibrato effect.
FM synthesis is tricky but can be put to great use when creating digital/electronic sounds.
FM synthesis isn’t used in guitar or bass synth pedals.
Sample-based synthesis does away with any oscillators and instead uses recorded samples as its waveforms. Each sample has its own defined envelope, though further synth processing (filters, LFOs, etc.) can be used to manipulate the sound.
On a sample-based synthesizer, a single sample may be pitch-shifted to fit multiple keys in an effort to save memory and/or save time recording a sample for each chromatic note.
Granular synthesis is another type of synthesis that utilizes sampling.
Samples are split into 1 – 50 ms* pieces known as “grains”, which are played back at different speeds, phases, volumes, frequencies and with other parameters changed.
*1 – 50 ms is typical but not an absolute rule.
An input signal, then, is sampled rapidly and is played back in interesting ways. These samples are essentially the osciallators for the granular synths.
Granular synthesis can get really strange and is capable of producing incredibly complex waveforms.
Monophonic Vs. Polyphonic Synthesizers
Most instrument (both acoustic and electric) are either monophonic or polyphonic. Synthesizers can also be either monophonic or polyphonic.
What’s the difference?
Monophonic synths can only play one note at time. Mono = one. Phonic = voice.
Polyphonic synths can play multiple notes at a time. Poly = many. Phonic = voices.
Guitars, as you could guess, are polyphonic. Guitar synth pedals, however, may be monophonic or polyphonic.
When playing through a monophonic synth pedal, only one note can be triggered at a time. This may cause issues if we’re attempting to feed the pedal chords. Polyphonic synth pedals, however, should be capable of tracking guitar (or bass) chords at their inputs.
There’s a whole lot more to know about mono and poly synths. This is simply a note on what to expect from a monophonic or polyphonic synth pedal.
What Is A Synth Pedal?
When doing your research about synth pedals, things can get rather confusing.
In the truest sense, a synthesizer pedal (for bass and/or guitar) is its own synthesizer that takes an input signal and uses this signal to trigger its oscillator(s).
Synth pedals can be monophonic (only recognize and produce one note at a time) or polyphonic (recognize and produce mutliple notes at a time).
In this sense, synth pedals are unlike practically all other guitar/bass effects pedals. They do not actually affect the signal of the input.
Instead, the input signal is read as a controller, giving information about a pitch or note value as well as dynamics (amplitude, ADSR, etc.). This “controller” would be analogous to a key on the typical keyboard synth controller, which reads pitch and amplitude as well.
So then, a synth pedal is an actual synthesizer that utilizes a guitar or bass signal to control its oscillators. These synths are generally subtractive in nature.
However, that’s not exactly the case. There are many other pedals on the market labelled as “synths” that do not fit this description.
Some pedals do affect the guitar signal to make it more “synth-like” and some have the typical controls of a synthesizer without actually having oscillators. Some pedals sample the incoming guitar or bass signal and use that as their oscillator. Other pedals distort the incoming signal to a point that it resembles a common “synth” waveform.
So, I guess a more fitted (and vague) answer to “what is a synth pedal?” would be “any pedal that either has a built-in synthesizer or any synth-like properties whatsoever”.
Types Of Synth Pedals
So we’ve gone over the general types of synthesis. Now let’s go over the types of synth pedals we’ll likely encounter in the world.
Note that, by the previous section, some of these “synth” pedal types aren’t actually synths and are simple synth-like in their operation and sound.
The different types of synth pedals are as follows:
- Analog-Oscillator-Based Synth Pedals
- Pitch-Multiplier Synth Pedals
- Granular Synth Pedals
- Fuzz-Based “Synth” Pedals
Let’s discuss each type in more detail, shall we?
Analog-Oscillator-Based Synth Pedals
When most people talk about synth pedals, these are the pedals they’re discussing.
These pedals, though not necessarily analog, are designed with built-in oscillators that are controlled by the input signal. They do not affect the incoming guitar/bass signal to turn it into a synth. Rather, they are the synth!
With this type of synth pedal, the input signal will be calculated via digital signal processing. The fundamental frequency (note) and dynamics (amplitude, sustain, etc.) are obtained from the input signal and this information is used to trigger the oscillators of the synthesizer.
In this way, our guitar signal is turned into a synth signal. Many of these synth pedals have multiple patches (synth sounds) to choose from, making them very versatile.
The Boss SY-1 Synthesizer (link to check the price on Amazon) is a digital polyphonic guitar synth pedal that uses the input signal to control its internal synth engine with 121 analog-style patches.
The Electro-Harmonix Bass Mono Synth (link to check the price on Amazon) is a digital monophonic bass synth pedal that uses the input signal to control its internal oscillator section with eleven different built-in synth patches and eleven more slots for user-created presets.
The Red Witch Synthotron II (link to check the price at Red Witch Pedals) featured two analog synth oscillators, each with its own level, decay and octave switching. This pedal also offer amplitude modulation, an envelope filter and a sample hold section.
Boss and Electro-Harmonix are both featured in My New Microphone’s Top 11 Best Guitar/Bass Effects Pedal Brands To Know & Use.
Pitch-Multiplier Synth Pedals
Pitch-multiplier pedals are sometimes refered to as synths, though they technically aren’t. However, by adding octaves and/or other pitch-shifted signals into the mix, these pedals can surely sound “synthetic”.
By adding more harmonics to the signal, we can achieve new timbres that exceed what is possible with guitar strings, pickups and amplifiers alone. This type of pedal is closely related to additive synthesis in that way.
Slap a filter and/or an envelope control and you’ve got yourself a pedal that approximates a synth!
The famous Electro-Harmonix POG2 (link to check the price on Amazon) is a polyphonic pitch-multiplier “synth” pedal allows us to stack 4 octaves in addition to the dry sound:
- -2 octaves
- -1 octave
- +1 octave
- +2 octaves
The polyphonic octave generator also features an attack control (ADSR), a low-pass filter and a detune (chorus) function.
The Electro-Harmonix Bass Micro Synth (link to check the price on Amazon) is similar to the POG2 mentioned above. This bass synth pedal utilizes multiple pitch-shifted voices:
- -1 octave (sub)
- +1 octave
- Square wave (achieved via fuzz distortion)
On the “subtractive synth” side of effects, the Bass Micro Synth has an attack control along with an envelope filter sweep.
The Meris Enzo (link to check the price on Amazon) is a complex and highly-versatile “synth” pedal that doesn’t have any oscillators. This pedal has pitch-shifting at its core but also utilizes multimode analog style synth filters, ring modulation, envelopes along with time and modulation effects to create synth-like tones.
Meris is featured in My New Microphone’s Top 11 Best Boutique Guitar/Bass Pedal Brands To Know & Use.
Sample-Based Synth Pedals
Sample-based synth pedals utilize samples rather than oscillators to produce their sound.
These pedals are few and far between since we’re typically concerned with real-time effects rather than with samping when we’re playing guitar or bass.
However, sampling and resampling our instrument on the fly can yield some awesome results.
The Hologram Infinite Jets Resynthesizer (link to check the price on Amazon) samples the input signal and processes it in a multitude of different ways before playing it back to us. The pedal is triggered by the input signal dynamics and uses the input signal as the basis for its synthesis.
Sampling, of course, takes time and so many of the Infinite Jets’ effects are delayed after the dry signal.
Granular Synth Pedals
Granular synth pedal utilize granular synthesis and are among the most experiemental pedals on the market.
These pedals sample the input signal in 1 – 1000 ms pieces (grains). These grains are then modulated and played back at different speeds, phases, volumes, frequencies and with other parameters changed.
These grains are essentially the osciallators for granular synth pedals.
The Pladask Elektrisk Fabrikat (link to check the price at Pladask Elektrisk) is a multi-effects processor with 16 different algorithms. It’s based on granular synthesis and modified sample playback. Its functionality includes granular time stretching, pitch shifting time stretching, freeze and shuffling effects, glitching sample playback and a beat repeater.
The Red Panda Particle (link to check the price on Amazon) is a granular synth, delay, and pitch-shifting pedal. Its engine samples, rearranges, shifts, and mangles the input signal, utilizing granular synthesis in real time.
Red Panda is featured in My New Microphone’s Top 11 Best Boutique Guitar/Bass Pedal Brands To Know & Use.
Fuzz-Based “Synth” Pedals
Fuzz pedals are effectively distortion pedals with a ridiculous amount of distortion.
In fact, fuzz circuits distort guitar (and bass) signals so much that the output signals often resembled square waves.
A square wave is a basic oscillator type for synthesizers to use.
So then, fuzz pedals are sometimes called “fuzz synths” due to the fact that they turn a guitar (or bass) signal into a common synth osciallator wave form.
Add some synth effects like filters, LFOs and envelopes and you’ll have yourself a fuzzy “synth” pedal.
To learn more about fuzz pedals, check out my article Guitar Pedals: Boost Vs. Overdrive Vs. Distortion Vs. Fuzz.
The Seymour Duncan FOOZ (link to check the price on Amazon) is a great example of a fuzz pedal with synth controls (LFO, envelope and filter).
The Keeley Electronics Synth-1 (link to check the price on Amazon) has the term “synth” in its name but is really based on a fuzz circuit. The pedal features a filter and attack (ADSR) control along with a switch to alter the fuzz distortion from a square wave to a sawtooth wave to a triangle wave.
Keeley Electronics is featured in My New Microphone’s Top 11 Best Boutique Guitar/Bass Pedal Brands To Know & Use.
Other Synth-Like Effects
Some effects can yield guitar tones that sound similar to synth patches. We’ve already discussed the fuzz effect, which sometimes gets the “synth” label attached to it. However, there are more.
A few effects that may sound “synthy” when set up in certain ways include:
Let’s touch on how each of these effects, when affecting guitar or bass signals, sounds like it could have been produced by a synthesizer.
Like fuzz, we’ve already touched on pitch-shifting and harmonizer pedals that get labelled as synth pedals. These pedals typically also have filters and/or envelope controls.
Guitars, by themselves, can harmonize easily. There are too many chord voicings to count on a guitar.
However, the pitch-shifting circuits used to harmonize, or to simply shift the pitch of, the guitar often sound somewhat un-guitar-like. Removing the dry signal or adding several layers of harmonized octaves can totally change the tone of the guitar into something that more closely resembled a synth.
To learn more about pitch-shifting and harmonizer pedals, check out my article What Are Pitch-Shifting Guitar Pedals & How Do They Work?
Ring Modulation Pedals
Ring modulation pedals are among the strangest pedals around.
These pedals combine a modulator signal with the direct/carrier signal to create create two brand new frequencies which are the sum and difference of the signals. The modulator wave is typically a sine wave selected by the effects unit while the input signal is from the guitar.
The ring modulation effect works similarly to amplitude modulation. A slower modulator signal would cause a noticeable tremolo. As the frequency of the modulator signal is increased, it begins affecting the tone of the signal rather than the amplitude.
This is analogous to FM synthesis, though it’s the amplitude that is being modulated at a fast rate rather than the frequency.
The Fairfield Circuits Randy’s Revenge (link to check the price at Reverb) is a great ring modulator with sine and square voltage-controlled oscillators. The sine and square waves are toggled via the top switch. The resulting sound can, in some instances, sound like a synth (though ring mod is a fairly recognizable effect).
The bottom switch toggles between high-speed and low-speed, allowing this ring modulator pedal to also act as a tremolo.
Bitcrushing is a digital audio effect whereby the resolution (bit-depth) and/or bandwidth (sample rate) of the digital signal is reduced. This reduction causes varying amounts of distortion in the signal due to the increase of quantization noise.
Slight bitcrushing can produce a warm saturation-like distortion in the guitar tone.
However, if we were to really crush the signal, we could reduce it to look pretty close to basic synth oscillators (sine, triangle, square, sawtooth, etc.). Think of the sound of 8-bit music from older video games to get a sense of overly bitcrushed sounds.
The EarthQuaker Devices Bit Commander (link to check the price on Amazon) is defined as a monophonic synth pedal and has excellent bitcrushing capabilities (along with pitch-shifting/harmonizing).
EarthQuaker Devices is featured in My New Microphone’s Top 11 Best Guitar/Bass Effects Pedal Brands To Know & Use.
It may odd to see delay pedals on this list. They typically do not make a guitar sound like a synth. In fact, delay is an effect that all instruments can benefit from.
However, there is a way to make a delay pedal sound like a synth. Let me explain.
Delay pedals typically have a feedback loop. This is how we get multiple delays (by feeding the delayed signal back into the delay circuit).
Turning the feedback level up introduces more and more repeats to the output signal.
If we were to turn the feedback level all the way up, we’d get a mess of a feedback loop that would overload the pedal and, potentially, everything after it in the signal chain.
Just before this extreme, there’s a sweet spot where that feedback loop will cause the delay pedal to self-oscillate. In this state, we can keep the output of the delay pedal consistent in level without adding any signal to the input.
Once we’re in self-oscillation territory, the output will resemble a synth sound more than a guitar tone. Adjusting the delay time will effectively alter the pitch of the output signal. In this way, a delay can sound like a monophonic synth with glide/glissando as we change the pitch with the delay time control.
The Boss DD-8 (link to check the price on Amazon) is a great example of a digital delay pedal that can be made to sound like a synth.
To learn more about delay pedals, check out my article What Are Delay Pedals (Guitar Effects) & How Do They Work?
To learn about all pedal types, check out my article The Full List & Description Of Guitar Pedal Types.
Typical Controls On Synth Pedals
Synth pedals, like most guitar/bass effects pedals, will have controls that will alter their parameters.
The most common controls for synth pedals to have are as follows:
- Effect level (wet/dry mix)
- ADSR (Attack, Decay, Sustain, Release)
- Low Frequency Oscillator
- Preset Recall
Effect Level (Wet/Dry Mix)
The effects level with control the relative mix between the direct “dry” signal (the guitar signal) and the effect “wet” signal (the synthesized signal).
This control may be referred to as the mix, wet/dry, blend or other names.
The mode/type control is sometimes labelled as the “oscillator” control.
This parameter will alter the oscillator of the synth’s hardware. Sometimes this switch is discrete and changes between distinct oscillator waveforms. Other times it’s continuously variable like a wavetable synth oscillator.
A tone control could alter a number of things.
It could simply change the EQ of the synth pedal’s output.
It could also alter the waveform of the oscillator itself, which would, by the nature of audio, also alter the EQ.
Sensitivity refers to how the input signal dynamics will trigger the synthesizer.
Turning up the sensitivity will allow quieter input signal to trigger the oscillator more intensely. Turning the sensitivity down will make it so that harder notes must be played to trigger the oscillator with the same intensity.
Filter controls can adjust a number of different filter types in the pedal’s circuitry. Low-pass filters are common. High-pass, band-pass and wah-type filters may also be used.
ADSR (Attack, Decay, Sustain, Release)
ADSR controls alter the envelope of the synth pedal’s signal by adjusting the time and/or amplitude profiles for the attack, decay, sustain and/or release of the signal.
Low Frequency Oscillator
A low frequency oscillator (LFO) control can be added to a synth pedal’s design.
A lot can be done with this control, including the routing to various other parameters as well as the speed, shape and depth/amplitude of the LFO.
Some synth pedals allow user-defined presets to be saved and recalled. These pedals will obviously have controls to save and recall these presets.
Tips On Using A Synth Pedal
Synth pedals open up a new world of sonic possibilities for us mere guitarists and bassists.
Here are a few tips to help get the most out of your synth pedal.
- Play some real synthesizers in your spare time
- Spend some time with the different oscillators
- Play to the pedal
- Use single notes with monophonic synth pedals
- Read the manual
Play Some Real Synthesizers In Your Spare Time
That’s not to say the synth pedals are not real synthesizers. In many cases, they are.
However, to sit down (or stand) with a keyboard-controlled synthesizer and jam out will open up new ideas as to how you could potentially use your synth pedal.
In general, a key-based synthesizer will be a bit more involved and have more controls available for tweaking. By playing these synth and listening to how they react to our playing, we can better understand how our synth pedal will react to our guitar playing through it.
Spend Some Time With The Different Oscillators
Spent time exploring the pedal to get the most out of it. This is good practice for the available oscillators and all the other settings and adjustable parameters the pedal offers.
There’s likely a whole lot of functionality and interesting sounds just waiting to be found in a synth pedal. It’s up to you to find them!
Play To The Pedal
This kind of ties in to playing keyboard-based synths. To get the most out of whatever synthesized sound you’re running from your pedal, it’s a good idea to play the notes (or chords in polyphonic models) that sound great with the synthesized sound.
If the synth pedal sounds like trash to you, it may just be that your blues licks sound better with a clean guitar tone than with a sawtooth swell synth patch.
Use Single Notes With Monophonic Synth Pedals
When playing a real monophonic synth pedal (that has real oscillators), it’s important to only input one note at a time. Too much harmonic information from the guitar or bass can lead to poor performance as the pedal attempts to distinguish a single note from a chord.
Read The Manual
This may be lame (Pink Floyd didn’t read the manuals to their synths). However, if you’re looking to tap into the full functionality of your synth pedal, the manual will, in most cases, shed light on something you haven’t thought of doing.
If you’ve made it this far into this article, I know you can read!
Where Should Synth Pedals Go In The Signal Chain?
As we’ve discussed, synth pedals are designed to use clean guitar and/or bass guitar signals to control their built-in synthesizers.
Therefore, it’s best to have these pedals at the very front of the pedalboard signal chain or just after the utility pedals (tuners, buffers, etc.). Having the synth pedal just after the guitar or bass in the signal chain means a cleaner signal will be triggering the synth circuits the pedal’ will work as it’s supposed to.
Of course, putting the synth pedal further down the line so that its input is affected by other pedals can lead to some interesting results. Perhaps the synth will be triggered incorrectly which can lead to interesting results. Experiment and see what you can get!
To learn more about ordering pedals in your rig/pedalboard, check out my article How To Order Guitar/Bass Pedals (Ultimate Signal Flow Guide).
MIDI Synth Pedals & MIDI Guitars
Earlier in the article, when defining synth pedals, I contrasted the input control of a typical guitar synth pedal with that of a typical synth. Whereas the synth pedal was controlled by the guitar audio signal, the “regular” synth was controlled by a keyboard and/or MIDI.
Well, there are also synth pedals for guitar and bass that work on MIDI (Musical Instrument Digital Interface).
In this case, we would need a MIDI instrument to plug into the pedal.
The Boss SY-1000 (link to check the price on Amazon) is an example of an extremely versatile synth pedal that takes a MIDI input.
MIDI guitars can be kind of clunky. Luckily, we can convert our “regular” guitar into a MIDI guitar with a MIDI pickup.
The Roland GK-3 (link to check the price on Amazon) is a popular example of a MIDI pickup for guitar. The GK-3B is for bass.
MIDI is one of the greatest tools in the audio industry. It would talk a whole other article (or several) to cover all there is to know about the Musical Instrument Digital Interface protocol. In this article, we’ll define the basics.
The first thing to note is that MIDI does not carry audio signal (analog or digital). Rather, it transmits digital information or “messages” in the form of 8-bit bytes at 31,250 bits per second. This info could potentially trigger a synth (or sampler) to create audio.
These messages communicate the following information via MIDI:
- The note(s) being pressed
- The moment the note is engaged (pressed) and disengaged (released)
- The velocity (how hard the note is pressed)
- After-tough (if the pressure on the key changes)
- Pitch bend
MIDI supports up to 128 notes, which is more than we’d ever need. It also has 128 different velocities (ranging from the values 0 to 127).
So MIDI is, itself, silent. It doesn’t actually produce audio or sound. However, it is a standard for controlling digital instruments including synthesizers.
The ubiquity of MIDI in music makes it understandable that synth pedals could use a MIDI in. However, a typical guitar or bass guitar has a quarter-inch output, not a MIDI output. This is where MIDI pitckups come into play.
A MIDI pickup, like a typically electromagnetic or piezoelectric pickup, is designed to “pickup” information from the guitar and output it to a connected device.
Typical guitar pickups work by converting the vibrating strings into electrical audio signals.
MIDI pickups work by capturing the vibrations of each string individually and sending this information to a decoder. The highly-involved decoder will convert this info into MIDI.
MIDI pickups are commonly bought spearately from guitars. They are generally designed to mount to a guitar. Of course, custom work can be done to house the MIDI pickup internally do it’s not so obvious.
A MIDI pickup will generally fit between the bridge and bridge pickup of an electric guitar or bass.
These pickups are divided, meaning that each string gets its own sensor. This makes sense since only one note can be played per string at any given time but multiple notes can be played simultaneously using multiple strings.
So each of the MIDI pickup’s divided pickups (6 for a 6-string) will decode its own MIDI information (with note value, velocity, etc.).
The pickup’s output will be MIDI information that can effectively drive a synth pedal with MIDI in. When set up, a MIDI guitar can also control a “regular” synthesizer with a MIDI input!
Can you use guitar effects on bass? Effects pedals are often designed for guitar but will universally work with bass guitar as well so long as the connection is correct (typically a 1/4″ patch cable). Some pedals may have difficulty tracking the lower octave of the bass guitar but all pedals can work with bass guitar.
To learn more about running a bass guitar through guitar effects pedals, check out my article Do Guitar Effects Pedals Work With Bass Guitar?
Can you run a synthesizer through guitar pedals? Yes, we can run our synths and keyboards through guitar pedals and take advantage of the wide variety of effects pedals. However, to get the most out of our pedals, we should attenuate the output signal of the synth/keyboard (from line level to instrument level) before it reaches the pedal.
For more information on connecting synths to guitar pedals, check out my article Do Guitar Pedals Work With Keyboards & Synthesizers?