8 Best Free Saturation VST Plugins: 2022



Jul 9, 2022

When it comes to making your music sound fuller and warmer, it’s all about audio saturation. Saturation is the secret production tool that makes all the difference to your mix, transforming dull and lifeless tracks into rich and exciting sounds.

It does this by subtly overloading audio signals with harmonic distortion and compression. Traditionally, producers added saturation to sounds using old gear like tape machines and vintage tube compressors.

But how do you add saturation to your mix without this equipment?

There’s a huge range of free saturation plugins that emulate the sound of analog audio processing equipment. Each comes with a unique saturation style, offering different tube, tape and transistor effects.

We’ve put together a list of the best free saturation VST plugins to help get started. The free saturation plugins on this list offer a truly impressive sound quality. These picks are chosen on quality, detailing, functionality and ease of use.

Summary: Best free saturation VST plugins (2022)

Best free saturation VST plugins (2022)

1. Saturation Knob – Softube

Saturation Knob by Softube: user interface

Softube Saturation Knob is one of the most well-known free saturation plugins amongst producers. It has been around for some time and remains popular thanks to its quality sound and simplicity. This free saturation plugin is so easy to use. It features a large saturation knob with three saturation type settings to choose from below: keep high, neutral and keep low.

  • Keep high – this only saturates lower sound frequencies in your track or mix. Perfect for giving guitar, synth and bass tracks a warmer or slightly distorted sound, without losing clarity in higher frequency sounds.
  • Neutral – this setting affects the whole signal, saturating high, mid and low sound frequencies. This is great for thickening synths and adding warmth to vocals.
  • Keep low – this leaves those low frequencies unsaturated. Ideal for adding saturation to sounds without causing any muddiness to low-end sounds. For example, saturating a drum loop without over-saturating the kicks.

No matter which setting you choose, the end result is always high quality with perfectly saturated sounds. 

It is hard to believe that this saturation plugin is free. It is even used by Grammy award winning music producers. Whilst this plugin is free, you do need a license to run it - but getting this is as quick and simple as using it. Simply register an account with Softube, then download the free Saturation Knob plugin.

Overview: Saturation Knob - Softube

Best for
  • Ease of use and simplicity
  • High quality saturation
  • Three saturation type settings
  • Mac OS X 10.13 up to 12
  • Windows 10 and 11 64-bit
System requirements
  • 8GB RAM
  • 8GB hard disk space

2. Tube Amp – Voxengo

Voxengo Tube Amp User Interface

Tube Amp is a free saturation plugin by Voxengo, a developer that creates a range of quality free plugins. Voxengo’s Tube Amp plugin saturates sounds by emulating a single-tube microphone preamplifier.

For a free plugin, Tube Amp comes with a lot to offer. 

This VST offers 3 main modulation functions: drive, bias and low-pass filter. These rotaries can be used to control the amount of saturation that is added to the sound, and to which frequencies the saturation should target.

  • Drive – this lets you control the amplitude of the harmonic saturation. Increase drive for a heavier saturation or tube distortion effect.
  • Bias – this setting controls the ratio between the original sound signal and the harmonic frequencies.
  • Low-pass filter – control the sound frequencies that are saturated and reduce the high-frequency range. 

Tube Amp’s VST interface also lets users switch between two processing modes: mode 1 and mode 2

Mode 1 results in quieter and subtler saturation, whereas mode 2 offers louder and more pronounced saturation. Control output gain and monitor amplitude (dB) with a handy visual meter.

Overview: Tube Amp - Voxengo

Best for
  • Better as a distortion or overdrive plugin
  • Also suitable for more subtle saturation
  • Customisable interface
  • macOS 10.11 and later
  • Windows (32- and 64-bit)
System requirements
  • 4GB RAM
  • 2.5 GHz dual-core or faster processor

3. PreBox – Analog Obsession

Analog Obsession are a fantastic indie developer, known for creating a range of free VSTs – many of which include free saturation plugins. PreBox is just one of the free saturation VSTs that they offer. All of their VSTs have something unique to offer, but PreBox stands out as one of their best free saturation plugins.

This plugin is modelled off several analog circuits, incorporating 11 different preamp settings based off unique models. For instance, the Reisong A10M tube amp and Hamptone HVTP2 Tube MicPre.

Each setting offers a unique harmonic quality to it, making PreBox a highly versatile tool for saturating different instruments and sound frequencies. Users can create different forms of harmonic generation with several options to suit the style of music.

It comes with handy input and output settings, which can be modulated to add even more harmonic saturation. It also offers a high-pass and low-pass filter. The high-pass filter can be used to effect frequencies up to 380Hz, though the low-pass filter only has one setting: 3kHz.

Overview: PreBox - Analog Obsession

Best for
  • 11 different saturation types
  • Easy to use
  • Selectable HFP & LPF
  • macOS
  • Windows

4. TUBA – Analog Obsession

TUBA by analog obsession

Another great free saturation plugin from Analog Obsession, TUBA offers a simple emulation of tube-based saturation.

This plugin creates complex harmonic generation right off the bat. Users can increase the amount of harmonic distortion using the high and low gain settings, as well as control high and low-pass frequencies.

TUBA also offers a mic and line switch, which can be used to set the input sensitivity to incoming audio signals. The level knob is gain compensated, resulting in a balanced and constant gain to avoid clipping and unpleasant distortion.

The phase inverter provides a unique effect that is rarely seen across other free saturation plugins. This inverts the phase of the audio signal alongside the original signal, resulting in phase cancellation between the two.

TUBA is also available as part of the Analog Obsession NOS bundle, which includes free tube line amp and limiting amplifier plugins.

Overview: TUBA - Analog Obsession

Best for
  • Additional phase inverter setting
  • Simple and easy to use
  • Available in a free VST bundle
  • macOS
  • Windows

5. IVGI – Klanghelm

IVGI by Klanghelm

IVGI by Klanghelm is a popular classic in the world of free saturation plugins. This is a great saturation plugin for your final master bus, offering high-quality harmonic distortion and a simple plugin interface. 

IVGI includes 4 main saturation controls: drive, asym mix, output, and response.

Drive – controls the level of saturation added to your mix. This automatically reacts to the input signal to saturate the sound dynamically. 

Asym mix – adjusts the symmetry and amount of compression of the signal without affecting the harmonics too significantly.

Response – adjusts the frequency changes and introduces shelf filters. This lets you control which frequencies are saturated.

It also offers a VU and RMS meter. These help monitor output levels, avoiding oversaturation and unpleasant distortion.

The best thing about IVGI is its quick, simple and convenient interface. IVGI’s simple but effective settings make it a perfect saturation plugin for mastering, adding fullness and warmth to your entire mix with little to no effort. And the best part, it’s free!

It can also be used on singular tracks to help certain instruments cut through the mix. Thanks to its ease of use and suitability for mastering, we definitely recommend this free saturation plugin.

Overview: IVGI - Klanghelm

Best for
  • Mastering and saturation across an entire mix
  • Ease of use and simplicity
  • Windows 7 SP 1 or higher
  • Mac OSX 10.9 or higher

6. Tape Cassette 2 – Caelum Audio

Tape Cassette 2 – Caelum Audio

If you’re looking for a free plugin that helps create those warm, fuzzy vintage sounds, Tape Cassete 2 is perfect.

Caelum Audio’s updated iteration of Tape Cassette, Tape Cassette 2, offers improved GUI and other tweaks that create a realistic emulation of analog tape sounds.

Tape Cassette 2 offers a distinct old cassette tape sound, ideal for any producer looking to create lo-fi tracks, or sounds reminiscent of the 80s and 90s. The sounds are impressively similar to that of a tape cassette. Let’s take a look at how the plugin achieves this sound.

  • Low pass filter – low-pass reduces the range of high-frequency signals, resulting in a more authentic tape cassette sound. Tape cassettes are notorious for their truncated high frequencies, accentuating warmer mid and low-range frequencies. 
  • Noise function – this adds sampled noise from tape cassettes, emulating the analog sounds of tape for an authentic sound.
  • Wow function – this adjusts the pitch of the audio signal, replicating the sound of older, used tapes. 
  • Flutter function – this also adjusts the pitch, although for higher frequencies. This results in phase cancellation and distortion.

Other impressive features include auto gain, which adjusts amplitude levels automatically. Tape Cassette 2 also comes with a bunch of presets to get you started.

This is a great analog tape plugin to help you add nostalgic warmth and saturation to your sounds, and is definitely worth the download.

Overview: Tape Cassette 2 - Caelum Audio

Best for
  • Nostalgic and authentic tape cassette emulation
  • Additional features such as tape noise samples
  • 'Wow' and 'flutter' modes for tape emulation pitch bends
  • macOS 10.11 or higher
  • Windows 7 or higher
  • iPadOS 11 or higher

7. Tomato Preamp – Roxolder

Tomato Preamp by Roxolder

Tomato Preamp is a free saturation plugin that offers a harsher, lo-fi sound.

Of the saturation plugins on this list, Tomato Preamp is probably the most suited to more extreme saturation and most distorted effects. It’s a great plugin for adding a unique sound character to your mix, affecting the audio signal with a sense of classic lo-fidelity recording.

It offers 3 tube model settings that each result in different lo-fi sounds: aged, fresh and new

  • Aged – the most distorted and harsh sounding setting. This adds a more heavy harmonic distortion to the signal.
  • Fresh – the middle ground. This setting adds harmonic distortion, but with less extremity than ‘aged’ mode.
  • New – the least distorted setting. This adds subtle harmonic distortion to the signal.

Each setting creates a different tonality, affecting frequencies to different extents. The settings have different high pass filters that remove low frequencies to result in a thinner sound.

This plugin is slightly limited in comparison to others on the list. The input, gain and output have little impact on the audio signal, giving little control to users. Though, overall, this is a good free saturation plugin for creating heavier harmonic distortions.

Overview: Tomato Preamp - Roxolder

Best for
  • Heavier harmonic distortion
  • Simple and easy to use, although limited in functionality
  • macOS
  • Windows

8. Szechuan Saturator - Coda Labs

Szechuan Saturator by Coda Labs

Let’s take a look at Szechuan Saturator by Coda Labs. This is one of those wackier free plugins that impress you not only because its sound quality is great, but because it’s super fun to use. 

Szechuan Saturator is designed in the style of McDonald’s Szechuan Sauce. Yep. Not only is its user interface fun, but it’s also capable of some pretty out-there saturation. Its saturation effects range from gentle, warm harmonic generation, to more extreme overdrive and distortion.

This makes a Szechuan a highly versatile saturation plugin. It offers a range of saturation settings, including intensity, mix, input gain and output gain.

Interestingly, it also comes with a built-in modulator. This is something that is not seen on many other free saturation plugins. Users can adjust the modulation depth, amount and rate to make an even more unique sound.

Overview: Szechuan Saturator – Coda Labs

Best for
  • Wide ranging saturation modes, from subtle to heavy distortion
  • Fun to use
  • Unique modulation settings
  • macOS
  • Windows

Which is the best free saturation plugin for beginners?

The majority of free saturation VSTs are suitable for beginners. Free plugins are often limited in functionality compared to paid VST plugins, so beginners will rarely encounter more advanced features. The most beginner-friendly free saturation plugins include Saturation Knob by Softube and IVGI by Klanghelm.

Both of these plugins are highly suitable for beginners and can be used easily when mastering a track.

Are free saturation plugins worth it?

There is much debate in the music production world about the use of paid vs free VST plugins. The reality is that many free plugins offer impressive sound qualities, some of which are actually better than their paid counterparts.

So, yes free saturation plugins are well worth it. And at no cost, there’s really no harm in downloading these and testing them out.

Several of the plugins on this list are used by reputable music producers. As mentioned, Saturation Knob is a hugely popular plugin even amongst several Grammy award winning producers.

For a full list of paid plugins, visit our related article covering the 11 best saturation VST plugins.

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