14 Free Synth Plugins for Your Collection

Article Content

It’s been a while since I surveyed the market for free software synths, so I thought I’d give it go and see what’s new and what has stood the test of time. Some of these instruments were released as prototypes or were the early experiments of developers just entering the market.

Free stuff is not always actually free. Often you will follow a link only to find out that it’s a free “demo”. Aren’t all demos supposed to be free?? In other cases, free software is dangled like a carrot in order to get your email address or to entice you into buying other products, preset libraries, add-ons, etc.

Well, business is business, and I suppose everyone needs to make a buck. I really don’t mind spending a few dollars for some shareware now and again to support a budding developer. But it behooves even the most experienced consumer to proceed with caution when the word free is thrown around.

What follows are some awesome sounding instruments in no particular order that are indeed free with very few strings attached. And if you can stomach a little extra spam, some of these may prove valuable additions to your stockpile of synths.

• Virtual analog with classic architecture, plus extras.
• Two oscillators, noise, ring modulator.
• Two LFOs with eight waveforms that are host-syncable.
• Audio source mixer with authentic overdrive and filter feedback.
• Twin filter related to Diva (early model).
• Unison with up to eight voices.
• Analog-type ADSR envelopes, loopable or LFO-triggered.
• Small modulation matrix with depth modulation from a second source.
• Chorus effect with three modes.
• MIDI learn / unlearn for hardware control.
• Resizable UI from 70% to 200%.
• Skinnable UI.
• Over 580 factory presets.

This thing is responsive as hell and sounds sweet! I love the stained and grungy aesthetic of the interface. It’s really hard to believe it’s free. But it serves its purpose I suppose because it truly whets the appetite for more stuff from u-he.

Dexed is an emulation of the classic FM synth: Yamaha DX7.

From the Github page:

“Dexed is a multi-platform, multi-format plugin synth that is closely modeled on the Yamaha DX7. Dexed is also a midi cartridge librarian/manager for the DX7. Do not expect this to be a perfect clone of a DX7 since this will take years in the open source world and multiple collaborators before getting there … Since Dexed is modeled on the DX7, the Yamaha DX7 Operating Manual can be used as a reference documentation.”

The interface is a little cluttered and is more functional than it is aesthetically pleasing, but there are a ton of sonic possibilities with this for those willing to dig in.

“MiniSpillage is a free professional quality drum synthesizer plugin featuring high-resolution 64-bit DSP processing.
MiniSpillage includes three exclusive drum synthesis algorithms along with distortion effects and resonant filters.”

• Bass Drum – Single oscillator bass drum synth with pitch sweep, internal FM and harmonic controls.
• Wood Drum – Flexible wooden drum model synthesizes natural and synthetic timbres from log drums to toms.
• Hi-Hat – Six oscillators closed and open hi-hat generator with a noise source and dual resonant filters.

This is a great free option for those that want to create their own drum sounds with modulation, filtering and distortion effects.

This is one is a bit frustrating and takes a while to get anything remotely usable. The interface is on the clunky side. But a little patience can be rewarding.

Lokomotiv is an analog retro synthesizer that is impressive from the first launch. Its austere interface is surprisingly responsive and sounds immediately great.

Oscillator:

• Mathematically generated high definition Oscillator without using wavetable or interpolation.
• Silky smooth 9X detuned sawtooth wave.
• Pulse wave with self PWM.
• Shape morphing sub-oscillator.

Filter:

ADVERTISEMENT

• MG ladder modeling multimode filter featuring Zero Delay Feedback technology.
• Routable filter Drive (Pre/Post).

Modulator:

• Natural Curved ADSR Envelope generator.
• One-shot LFO which can be used as envelope.

Specification:

• 1X OSC (Saw+ Pulse) + One Sub OSC, Noise Generator.
• 1X multimode Filter with Drive.
• 1X LFO, 1X Envelope Generator.
• Eight polyphonic voices, Mono and Legato mode supported.
• 64 Factory presets included.
• Native 64-bit, Mac and Windows OS supported.

This one sports a subdued color palette with beefy growls, preset chords and brass sounds. A bit of crackling when parameters are modified, but worth the time to download for sure.

Not long ago, Spitfire Audio released an ongoing series of completely free instruments called LABS. These are very, very simple sampled instruments with just a handful of controls and they sound really, really good. So far the collection includes:

• Charango
• Electric Piano
• Amplified Electric Cello Quartet
• Drums
• Strings
• Soft Piano

If you’ve used any of the Spitfire Sample Libraries before, you know how well they’re recorded, and these instruments are no exception. While you won’t get the flexibility or deep sampled variety of a full-scale library, you will get a great sound that can be slightly varied to taste. While these are sampled instruments as opposed to synths, they’re free and so good that I felt they warranted inclusion.

This is one my of favorite choices. The interface is accessible, clean and to the point and thick, beefy sounds are possible from the get-go. Really nice!

From the developer: “TAL NoiseMaker is an improved version of TAL-Elek7ro and has a completely new synth engine and a lot of improvements in sound and usability. The synth also includes a small effect section with a reverb, chorus and a simple bit crusher effect. A display shows the knob and slider values. This allows more control over the synth. A ring modulator and a syncable triangle are also part of this synth.”

TAL NoiseMaker includes new filter types and the self-resonating 6 dB low pass and notch filter. Its improved amplitude ADSR is very suitable for slow pads and for really fast envelopes. 128 factory presets included, 80 made by Frank “Xenox” Neumann.

Features:

• Three Oscillators. Osc 1, +/- 24 semitones, fine tune, phase control (saw, pulse, noise). Osc 2, +/- 24 semitones, fine tune, phase control (saw, rectangle, triangle, sine). Sub Osc (rectangle).
• Osc 1 PM for pulse waveform.
• Osc 2 FM controlled by Osc 1.
• Osc 1 & Osc 2 sync to sub osc (saw, pulse, rectangle, triangle (bipolar sync)).
• Adjustable master tune and transpose.
• Up to six voices.
• Portamento in mono and poly mode (off, auto, on).
• Ringmod modulates Osc 1 with Osc 2.
• Self resonating 4x oversampled filters (24 dB LP, 18 dB LP, 12 dB LP, 6 dB LP, 12 dB HP, 12 dB BP, Notch).
• Filter ADSR (negative and positive).
• Volume ADSR
• Routable ADSR, modulates Filter, Osc 1, Osc 2, PW, FM (negative and positive)
• Two LFO’s with different running modes: free, sync to host, triggered by note. Modulates filter, Osc 1, Osc 2, FM, PW, LFO rate, Panorama and Volume. Sine, Triangle, Saw Square, S&H, Noise. Positive and Negative modulation. Phase control.
• Adjustable Velocity-dependent control over volume filter contour and cutoff.
• Adjustable Pitch Wheel control over Cutoff and Pitch.
• One pole HP filter.
• Detune, detunes notes randomly.
• Juno chorus with different modes.
• A built-in reverb and delay.
• Adjustable filter drive.
• Bitcrusher affects Osc 1 and Osc 2. It’s a pre-filter stage effect.
• MIDI Learn for all knobs.
• Panic button.
• Easy to use, no hidden panels.
• 256 great presets (Presets by Frank “Xenox” Neumann, The Unshushable Coktor, Alexandra Sendy, TAL, Patrick Kunz).

Thump is a unique audio processor that allows you to synthesize low-frequency audio to add low end to a track or generate another sound entirely. Thump looks at the pitch and dynamics of its audio input and uses this information to control its oscillators. You can add low end to drums, augment a bass or even create synthetic drones.

Thump is ideal for beefing up a kick drum, adding low end to percussive tracks, recreating classic drum synth sounds and more. You can use Thump’s envelope driven, percussive sub-harmonic synth for the following things (among others):

• Build low-octave support for bass drum, tom, snare and other percussive tracks.
• Create kettle drum sounds from regular drum tracks.
• Recreate the sounds of classic drum synths like the TR-808.

The effect of Thump is similar to generating a sine wave or other waveform on a gated track that is side-chained to a transient on another track such as a kick. But Thump allows more control, two oscillators that can be changed on the fly and more pitch specific envelope control. If you like kicks that are thick as hell and challenge the range of human hearing, you will like Thump a lot.

NOTE: the instrument requires a transient input to be activated so you would use it like an insert rather than a standalone synth.

ADVERTISEMENT

While the interface is a bit nasty and pixelated, Synth 1 by Ichiro Toda is modeled after the Nord Lead 2 Red Synth and sounds decent. It doesn’t take long to get a few usable sounds and the onboard arpeggiator is great for experimenting.

“The PG-8X is a virtual synthesizer, inspired by the Roland JX-8P with the PG-800 programmer. The synth architecture is a standard 2-oscillator -> Filter -> VCA design. These elements can be modulated by a common LFO and one of two envelopes. The PG-8X is patch compatible with the JX-8P and can read and write JX-8P Sysex data”. (Manual)

Vital is a recent addition to this list which I happily included thanks to several users that called my attention to it. It is described as a “spectral warping wavetable synthesizer”. The basic free version is quite powerful on its own and has all the functionality of paid versions, which include additional presets, wavetables, samples, and LFO patterns.

Ready to elevate your ears?

It doesn’t have to take years to train your ears.

Get started today — and you’ll be amazed at how quickly using Quiztones for just a few minutes a day will improve your mixes, recordings, and productions!

Download for iOS

Download for Mac

The download and install of this beauty seemed unusually fast and I was up and running in less than a few minutes. I was immediately impressed after choosing a random preset to give it a spin. A thick, lush sound erupted and the intuitive interface invited experimentation with a robust collection of effects, modulators, and oscillation choices. The aesthetics of the GUI are particularly elegant for a free instrument, and the layout and clearly labeled parameters make this a very attractive and user-friendly instrument. It downloads as a plugin and standalone app compatible on all major platforms including Linux and also supports MPE. This is a feature-rich synth that is almost too good to be free!

I just recently downloaded my new favorite free synth – Surge! This is a full-featured hybrid instrument that has 3 oscillators (plus octave variations), 614 wavetables, customizable FM and dual filter routing, several LFOs and modulation envelopes, a full-blown FX section, key and channel split capability and an impressive array of presets by the developers and 3rd party contributors. The instrument is supported by volunteers and is completely open-source. It even has support for the new MTS-ESP plugin by ODDSound for microtonal capability. I experienced some redraw issues and couldn’t seem to resize the GUI running it as an AU in Logic Pro on my M1 MacBook Pro. But things worked flawlessly in Ableton as a vst3 and this thing sounds stunning!

This incredible freeware bundle from the great modular synth developer, Noise Engineering, includes two synths and Ruina, a great distortion plugin as well. All of these beauties have stunning graphics and sweet interfaces rarely seen in free plugins.

Sinc Vereor is a kind of software version of their Sinc Iter hardware module and uses wavemorphing and wave folding. It includes an onboard multimode filter, chorus, up to 16 voice polyphony, standard envelope controls and you can even load Scala files for microtonal tuning.

Virt Vereor is an algorithmic wave generator and additive synth with similar layout and controls. Both of these synths sound immediately amazing and scrolling through the presets demonstrate their sonic capabilities.

Add to this the cleverly named distortion plugin, Ruina, and the fact that all three are free and you get something that seems almost too good to be true.

Conclusion

While these instruments may not be the best things in life — they are free. And it has been my experience that there is something to be learned from every piece of software, as there is from all types of music. Experimentation and exploration yield untold rewards for the adventurous, and freeware is a great place to start your journey or a means to unshackle yourself, at least temporarily, from the financial constraints that plague us all.

—–

Check out my other articles, reviews, interviews and my video tutorial series, Synthesis 101 available exclusively on The Pro Audio Files.

Follow me on Twitter: @PMantione
Instagram: philipmantione

Synthesis 101: 4+ Hours of In-Depth Synth Training

Philip Mantione

Philip Mantione is a composer, synthesist, guitarist, educator and sound artist active in the LA experimental music scene. His music has been presented in festivals, museums and galleries worldwide. His current project is TriAngular Bent, an electroacoustic trio featuring Don Preston (founding member of Frank Zappa’s Mothers of Invention) and circuit bending virtuoso, Jeff Boynton. Details at philipmantione.com