In this post, we will be reviewing the 7 tremolo plugins that we consider to be the best on the market in 2021.
What Does Tremolo Mean In Music?
In music, Tremolo is defined as the rapid reiteration of a note to produce a trembling noise. The term can often be confused with vibrato. An easy way to discern the difference is to listen to the note’s pitch or signal affected by these effects. With Tremolo, a note’s pitch stays constant but sounds as though it is moving due to the shift in volume from a note’s repetition.
In modern music production, Tremolo can be used as an effect to create tonal dynamics around a signal. The phrase has traditionally been associated with bowed string instruments such as violins or guitars but has since evolved to be used loosely in other music areas. In the case of vocals, singers use tremolo to create a quiver over a sustained note.
With percussion or drums, Tremolo can be used as a rhythmic term to define a rumbling sound caused by soft, fast repetitive drum hits. Also, the effect has been widely used amongst electric guitar and keyboard players.
How Does A Tremolo Work?
A tremolo effect places amplitude modulation on a signal to create volume changes. A signal is sent into a tremolo effect unit and is routed through a low-frequency oscillator (LFO). This LFO causes the signal’s strength to rise and fall incrementally. The result is a wavy or quivery sound effect.
The lower the frequency of the LFO, the slower the rate of amplitude modulation. There are a few ways to create electronic Tremolo. The electronic effect was believed to have been pioneered by Harry DeArmond, who invented the Model 800 Trem Trol in 1948.
This stompbox was the world’s first guitar effects pedal, and it consisted of a tiny motor that shook a bottle with conductible fluid inside the pedal. The bottle’s shaking motion would cause a signal’s voltage to waiver and thus create a rhythmic, tonal modulation. The bottle that conducts electricity inside the Trem Trol effects pedal is essentially what LFO circuit units are modeled on.
As with most LFO based effects units, there are some oscillation parameters you can adjust while using a tremolo effect.
- Depth – Depth will determine the overall range between peak points of your signal’s modulation. This parameter can also be used as an alternative to a Dry/Wet Knob on tremolo effects.
- Shape – Oscillators can perform in different waveshapes to produce distinct modulations on a signal. The most commonly used wave shapes are Sine, Square, and Triangle. Sine and Triangle are generally identified as the smoother of these shapes, while saw and square can create more abrasive tones.
- Rate -- Most tremolo effects have a control that allows you to set the speed of the LFO. These modulations can either be assigned to a quantized rate or at a Hz rate of up to 25Hz on average.
What Does A Tremolo Sound Like?
The rapid signal fluctuations created by tremolo devices generate shivering or trembling audio effects. The effect can translate differently depending on the type of tremolo device you are using and the parameters you set on that respective device.
The shape of a waveform in a tremolo’s LFO will determine the effect’s primary characteristics.
Here’s a quick rundown of how the most commonly used tremolo waveshapes sound:
- Sine – Selected for its subtlety, a sine-wave tremolo produces very smooth and coherent oscillations in volume. At maximum value, its effect can enhance the blend of a signal due to its modulating properties’ gentle nature.
- Triangle -- The triangle wave is the most commonly used tremolo waveform among guitarists. The shape features in many guitar amplifiers and stompbox units and are revered for sounding distinct without being overbearing. The volume modulations generated by this shape are more rigid than a sine wave but still maintain a semblance of fluidity.
- Square – This is the most obtuse of the three tremolo waveforms. A square-LFO generates a very choppy oscillation around a signal, with more defined slopes between each peak and dip. The effect is likened to turning the signal on and off and produces a shuddering sound at high values.
7 Best Tremolo VST Plugins of 2021
1. SoundToys Tremolator Review
Tremolator is a minimal but very expansive tremolo plugin designed by Soundtoys audio programmers. This plugin hosts two straightforward interfaces with a generous selection of rhythmic and dynamic controls for users to experiment with. The emulators on the Tremolator are based on classic analog gear circuits such as the Fender Vibrolux amp.
- Rhythmic Envelope Editor
The rhythmic editor offers users a wide selection of rhythmic parameter controls that they can apply to their Tremolo’s LFO. These parameters include often overlooked parameters of rhythm control, such as groove and accent, and can help you generate some truly authentic volume modulations.
- Waveshape Editor
This feature lets you slightly adjust the curve or slope of your LFO waveshape. You can load in preset shapes for editing or design simple LFO patterns from scratch in the editor’s graphic window. The editor also comes with a smoothing function to help remove any glitches or pops caused by the effect’s processing.
- Dynamic Modulation Controls
The second interface on the Tremolator gives users a Dynamic Control menu. Here you can set the threshold, attack, and release of your effect, as well as adjust the Tremolo’s modulation speed and depth. You can automate these parameters or tweak them manually during playback or performance to help create distinct organic modulations.
Soundtoys Tremolator requires Windows & or higher and Mac OS X 10.10 or later. It is available in AAX, AU, and VST versions.
The Tremolater looks and sounds very much like something designed by guitar players for guitar players. However, the Rhythmic Envelope Editor’s addition makes it a handy tool for anyone looking to create punchy, tight modulations with their Tremolo. This plugin is very light on the CPU and links quite easily with external devices, making it an excellent asset for producers or engineers that use large effects racks.
2. Eventide Undulator Review
Eventide’s Undulator is modeled on the Tremolo preset that came with their popular H3000 analog multi-fx processor. The interface will be easy for most guitar players to adapt to as it resembles a stompbox unit. The controls on this plugin are easy to access for real-time use and would suit live performance situations quite well.
- Fast/Slow Toggle
This button toggles you between your primary Tremolo, and a second set to a slower relative speed. This trigger is excellent for creating unpredictable volume changes in your signal flow.
- Spread Parameter
The spread parameter allows you to place harmonics on top of your affected signal for a wider sounding tremolo. You can patch other effects into this one as you would on a modular synth.
- Secondary LFO
Beneath the primary controls in the center of the Undulator’s interface are a set of knobs that control a second LFO. This LFO adjusts the depth and speed of your Tremolo, and modulates its minimum and maximum values to your taste.
- Envelope/ADSR mode
Using this setting on your primary LFO will cause your signal’s modulation to be controlled by its own amplitude. This means that your Tremolo will rise and fall according to the peaks of your input signal. This unique Tremolo feels very organic and sounds excellent over drones, guitars, or synths.
The Eventide Plugin is available to Windows 7 and up users and Mac users with OS X 10.12 or higher. It’s available in VST, AAX, or AU formats.
If you’re someone who likes to use Tremolo in their effects chain during composition or live performances, you’ll enjoy the Eventide Undulator. It may not be the best plugin for building meticulous volume modulation patterns or sequences. Still, it can be beneficial for generating modulations that you can tweak on the fly. The addition of the secondary LFO controls makes for very intriguing modulations when patched in with the spread parameters and is ideal for giving signals a dreamy character.
3. Goodhertz Trem Control Review
Goodhertz has designed the Trem Control in collaboration with Theo Katzman of Vulfpeck fame. This is evident in the tube-amp style tremolo processing that comes with this plugin, as Katzman’s primary instrument is a Fender Stratocaster. The interface is straightforward on the eyes and features a range of basic digital faders and dropdown menus that give users meticulous control of their tremolo parameters.
- 8 Types of Tremolo Presets
Eight standard tremolo settings feature on the Trem Control plugin. You can choose to affect just the lows, mids, or high-frequency ranges. Alternatively, you can set your Tremolo to mid/side processing mode for some extra stereo clarity. Each of the presets is fully adjustable, and you can save your future use.
The Vibe fader blends in Trem Control’s signature tube saturation with your tremolo signal and adds some lush color to your output signal. You can push the effect to extreme values to generate shrill harmonic content.
This dial allows you to adjust the width of the peaks in your LFO cycles. Lower values equate to smaller sharper peaks, whereas higher values create broader slopes with smooth peaks.
- Advanced Shaping Feature
This tab is an extended menu that lets you enhance some of your LFO’s parameters. You have the option of setting the phase point in your LFO. There’s also a stereo bias dial, which adds a stereo panning effect to your Tremolo.
Trem Control works with Mac OS X 10.9 or higher and Windows 7 or later. It is available for download as a VST, VST3, or AAX.
The Trem Control gives you a very detailed understanding of how your Tremolo affects your signal, thanks to its ergonomic GUI. The Vibe control is perfect for guitarists looking to get rich harmonics with vintage amplifiers. This plugin isn’t just strictly for guitar players, and we recommend trying it out on various elements in your mix like drums, vocals, or keyboards.
4. Melda MTremoloMB Review
The MMultiband Tremolo by Mela Productions may seem a bit primitive at first look, thanks to its Windows 95-like design of its interface. However, this plugin has an impressive arsenal of signal shaping capabilities. This plugin sets itself apart by applying multiband volume modulation to a signal instead of standard volume automation.
- Up to 6 independent bands
Users can choose to affect six independent frequency bands on their dry signal. For example, you can set the high frequency to have a fast modulation rate while leaving the low-mids on a slow tremolo speed simultaneously. Try using this mode on padding instruments like strings or synths to give them some exciting motion dynamics.
- Step Sequencer
The MMultiband Tremolo comes with a fully customizable waveshape construction kit. There is a wide selection of predefined slopes and curves that you can utilize to build unique modulation sequences. Users can also save their sequences for future use.
- Built-in Limiter
The built-in limiter on this plugin will help you set appropriate gain peaks for your overall output. The limiter will also help clean up any signal clipping caused by the plugin’s processing. This feature will save you time when trying to blend your affected signal with your overall mix.
MMultiband Tremolo is available to Windows 7 and higher users and Mac users with OS X 10.9 or higher. It comes in 32 and 64-bit versions as a VST, VST3 AAX, or AU formats.
We can sing many praises about the MMultiband Tremolo plugin. The application of multiband mechanics to the tremolo effect is a novel but compelling idea. If used correctly, you’ll be able to generate endless volume automation sequences that will liven up any stagnant elements in your mix. Should you find the interface intimidating, there is an Easy Mode feature with basic controls that are easier to comprehend.
5. Puremagnetik Clusters Review
Clusters by Puremagnetik is punted as a harmonic tremolo shaper. The plugin’s interface has a very futuristic aesthetic with a handful of easy-to-use controls that create some stunning volume automation. This plugin is not only minimal in its design. It’s also relatively light on CPU despite its fast and reactive processing speed.
The Crossover knob on the Clusters plugin lets you choose how much of your input signal’s low and high frequencies are affected by your Tremolo. This handy feature divides your signal into two and plays them back together at slightly fluctuating speeds.
You can use this setting to either multiply or divide your Tremolo’s LFO speed. Higher settings produce harmonic overtones or ring modulations. This knob is not confused with the Rate control on the plugin, which sets the tremolo speed at quantized values.
- Animation Parameter
Users can adjust this setting to either have the crossover’s frequency response stagnant or modulate. This means that your Tremolo will shift up and down your signal’s frequency spectrum, creating some added motion dynamics to your input signal.
This plugin works exclusively with Windows 10 and Mac OS X 10.8 or higher. You can download it in either VST or AU formats.
The Clusters tremolo plugin is very well suited to producers who prefer dials and knobs over envelope editors and step sequence controls. The plugin interface is very intuitive, and the Clusters plugin comes with presets that range from smooth and subtle to harsh and avant-garde.
6. Kuassa EFEKTOR TR3604 Review
Efektor by Kuassa Audio is the perfect Tremolo for any novice producers or engineers or anyone who wants a compact, simple tremolo emulator. This plugin has just the bare essentials of tremolo generation, and Kuassa covers the basics pretty well, considering the minimal design of this plugin’s interface.
- 3- Way Waveshape switch
You can use this toggle to quickly switch your Tremolo’s primary LFO waveshape. There are sine, square, and Triangle slopes to choose from. You can also automate this switch between shapes to a metronome.
- A/B Switch
This feature lets you configure two sets of parameters to compare with a toggle switch. This is handy if you’re using the effect during a live performance and wish to have more than one type of tremolo sound in a song.
- Shape Knob
There are three modulation modes to select from in the Efektor’s shape parameter. Using the Shape control on lower values will implement smoother slopes on your LFO. Higher values will translate into steeper slopes and more distinctive modulations.
Efektor is available to Windows Users 7 or higher and to Mac users with OS X 10.6 or later. It comes in VST, VST3, AAX, and AU formats.
This plugin’s greatest strength lies in its small design. Some producers or engineers can’t afford to place intricate plugins on their CPU load. Some prefer to use plugins that don’t have dozens of dials, graphs, and switches. In these cases, many may welcome the Efektor plugin with open arms.
7. Pecheneg Tremolo Effect (FREE) Review
Pecheneg has become well known for designing simplistic diverse plugins, and their Tremolo Effect is no different. Users have access to a humble handful of parameter controls that range from waveshaping options to signal blending aids.
- Waveshaping controls
Users can choose from three primary types of waveforms: Sine, Square, and Triangle. You can also set the phase point of the Tremolo and adjust the symmetry of the LFO.
- Depth/Vol Knob
You can use these to mix your output into your overall mix. The Depth control acts as a Dry/Wet knob and determines how steep the curves of your LFO vary. You can use the Volume knob to set the gain level of your affected signal.
Pecheng’s Tremolo effect is compatible with Windows 7 and higher and with Mac Os X10.9 or later. It is available in 32 and 64-bit VST and AU formats.
The Tremolo Effect is a stable all-around plugin and won’t have you distracted with any complex graphs or LFO editors. The frequency and time sync features are entirely accurate and provide a surprising range of tonal dynamics for such an unassuming design. It’s also available for free download, which makes it worth giving this plugin a try.
3 Best Free Tremolo Plugins 2021
1. HY-Plugins HY-TP2 Review
The Hy-TP2 is a no-nonsense tremolo emulator from the HY Plugins. The GUI consists of 4 windows that handle the fundamental elements of tremolo processing. Users have eight tremolo waveforms to choose from, and you can adjust vital parts of your effect’s tone and stereo mapping with the Tremolo, filter, and output sections.
- Separate Low And High Shelf Filters
This Tremolo features two independent filters that determine which frequencies in your signal are affected by the Tremolo’s LFO. You can set independent parameters for either the low or high-frequency ranges of your signal, and this adds some movement to the overall harmonic saturation of the Tremolo.
- Smoothing function
The Smoothing control is placed at the bottom of the Mod Wave LFO editor. This control is handy for helping to remove any unwanted crackles or pops caused as a result of the Tremolo’s processing.
- Tremolo/Panning Controls
The HY-TP2 features three essential dials that control your tremolo controls’ depth, rate, and stereo width. You also have the option to sync your Tremolo to a click or to adjust it manually. The width dial acts as an auto-pan and can be used to create some interesting based effects.
HY-Tp2 is available to Windows Users 7 and above and to Mac Users with OS X. 10.9 or higher. It comes in 32 and 64 Bit VSt or AU formats.
Less is more in the case of the HY-TP2 tremolo plugin. There are just enough controls and settings packed into this emulator to give users the tools needed to produce crisp, dynamic tremolo processing. One minor hindrance is the lack of an oscilloscope or visual reference, as tremolo waves can sometimes sound deceptively similar to each other. However, if you have experience working with Tremolo, this plugin should be relatively easy for you to utilize without any visualizer.
2. NoiseAsh Action Tremolo (FREE) Review
We are big fans of the NoiseAsh Action Tremolo. The plugin hosts some awe-inspiring LFO capabilities, as well as a list of added effect devices that you can use to color, enhance or blend your affected signal. Some very attractive graphics provide feedback on your Tremolo’s timing and depth structures.
- Step Sequencer
Users can implement the 32-step sequencer to generate less predictable volume automation. The Action Tremolo includes a few predefined sequences that you can use as starting points to help you quickly create extended tremolo patterns.
- Drive Control
This essential drive device is placed directly after the LFO in the Action Tremolo’s routing. The control is ideal for adding some grit and color to your output, mainly if your Tremolo dulls your dry signal in any way.
- Auto Panning Mod
The panning feature on this plugin also uses waveforms to modulate your Tremolo’s LFO across the stereo image. You can use standard waveforms to set this stereo pan feature or even design longer panning patterns with a step sequencer.
If you’re looking to download Action Tremolo by NoiseAsh, you’ll need Windows 7 or above or Mac OS X 10.9.5 or higher. The plugin is available in VST, AAX, and AU format.
NoiseAsh has really outdone themselves with the Action Tremolo plugin. While it’s not the most in-depth plugin as far as tremolo emulators are concerned, it feels compact and complete as is. Toggling between settings and presets is a painless process with this plugin, and we can’t foresee anyone getting stuck or lost using the ACtion Tremolo’s controls.
3. Beijaflor TAS-X (FREE) Review
Anyone who is a fan of stereo-based effects will enjoy the TAS-X by Beijaflor. The plugin is made up of two LFO module generators that users can map and phase to their preference. The TAS-X is lovely if you’re looking for speedy access to a reliable minimalist tremolo effects plugin.
- Left and Right LFO-Modules
TAS-X consists of two independent LFO engines that you can configure with a range of shapes or automation. Adding panning to your Tremolo can vastly give it some added stereo dynamics, and you can push these LFO’s to generate some dizzying after-effects.
- Independent Dry/Wet Knobs
Most plugins and devices offer users a single dry/wet control to determine the overall strength or depth of that respective effect. The TAS-X features separate Dry and Wet knobs. You can use these to blend your dry input signal with your affected output signal, much like the effects send. This control gives you some added scope when it comes to finding a place for your Tremolo in your overall mix in situations like gain staging.
- Smoothing and Limiting Control
The built-in smoothing and limiting controls will help you tame any spikes in amplitude caused by the TAS-X’s processing. You can use the limiter to increase your overall output level without causing any clipping.
TAS-X is available in VST, VST3, and AU formats. Windows Users require seven or higher, and Mac users will need OS.X 10.9 or later
The TAS-X plugin can be likened to Ableton’s stock auto-pan device, with the addition of tremolo processing. Producers and engineers should find the UI relatively easy to navigate and understand, as there are no intense, moving graphics or complex LFO editors with this plugin.
It may not offer users highly in-depth control of their LFO’s or have any added effects like drive or saturation, but the Tas-X will sound great when used in conjunction with other effects units or plugins.
Things Motor Review
Motor is more a morphing tool than a tremolo plugin, but that’s what makes it interesting.
The plugin is based on a hardware unit that used a real motor for modulating sound. The relatively simple interface of this plugin houses a rate parameter, wave selection, and more knobs that are straightforward. Turning up the Tremolo parameter at the bottom adds tremolo to your sound.
- Variable LFO Waveforms
The graphic in the center called “Wave” lets you select from a variety of waveforms to use for your tremolo effect. The shapes range from a simple sine wave and square wave to sawtooth or morphed shapes.
- Side-Chain Input
Using the side-chain input, you can choose to “tremolo” between two sounds. In other words, it switches between any two inputs at the rate you assign to it. Further, you can control the loudness of either signal using the Balance knob.
- Easy Toggle
You can turn the effect on or off using the ▶ button labeled Motor at the bottom right. However, since this is an emulation of hardware, the button will slow down the “motor” to stillness or speed it up to the assigned speed. Turning down the Speed knob next to the button will make the button instantaneous.
Motor is available for Windows 7 or higher and macOS 10.9 or higher, both 64-bit only. It comes in VST 2/3, AU, and AAX formats.
This plugin is far more than a simple tremolo effect. Using its other parameters, you can get strange audio modulation and almost granular effects. So, we think it’s a wise investment for the flexibility you will get.
Tips and Tricks for using Tremolo
- While the tremolo effect is traditionally used for guitar, it can sound amazing over many other instruments that share the same frequency range or timbre, such as strings, organs, or even vocals.
- When setting your Tremolo, solo the track that you affect and listen to it with the metronome. Much like bass or drums, this effect can have a rhythmic sweet spot, and you want to try and get your Tremolo to groove with your click track. Sometimes this will mean setting the rate and speeds manually instead of using quantized values.
- Remember that with effects, less is often better than more. You want to make sure that you don’t land up intruding on other mix elements with your Tremolo. When setting the depth or dry/wet levels, start with small amounts and work your way up until you hear something clash, then back the effect off until it sits neatly inside your mix.
Tremolo can be a potent tool when used in the right context. There are several tremolo plugins listed above that should suit most types of audio requirements and ambitions. If you’re looking to explore the depths and possibilities of this effect, we recommend trying the Trem Control by Goodhertz or the MTremoloMB by Melda.
Both give users more than enough waveshaping and signal blending options and controls. However, if you’re looking for a tremolo plugin that is light and simple, give the Efektor by Kuassa audio a shot. Thanks for taking the time out to read through our list of the top tremolo plugins of 2021. We hope this article left you ready to explore and inspire!
Kieron Brown is a multi-instrumentalist, producer, and writer from Cape Town, South Africa.
He has spent over a decade in the music industry working as a musician, events curator, and consultant.