- 1 General
- 2 Hardware
- 3 Listings
- 4 Equalisation
- 5 Mastering
- 6 Compression / limiting
- 6.1 VLevel
- 6.2 DPL1
- 6.3 Radium Compressor
- 6.4 Visual Compressor
- 6.5 Molot Lite
- 6.6 CharacterCompressor
- 6.7 Xhip Compressor
- 6.8 Xhip Limiter
- 6.9 x42-limiter / dpl.lv2
- 6.10 darc.lv2
- 6.11 LazyLimiter
- 6.12 CompBus
- 6.13 Audio Compressor & Limiter
- 6.14 SimpleCompressor
- 6.15 RoughRider3
- 6.16 Squeezer
- 6.17 Windows VST
- 7 Gate
- 8 Delay
- 9 Reverb
- 10 Sound retainer
- 11 Tremolo
- 12 Vibrato
- 13 Phaser
- 14 Filter
- 15 Exciter
- 16 Chorus
- 17 Flanger
- 18 Ring modulation
- 19 Shaping
- 20 Preamp
- 21 Rotating speaker
- 22 Distortion
- 23 Valve
- 24 Frequency shifting
- 25 Pitch shifting
- 26 Harmonizer
- 27 Phase vocoder
- 28 Noise reduction
- 29 Echo reduction
- 30 Response and convolution
- 31 Multi
- 32 Rack based
- 33 Various collections
- 33.1 MOD
- 33.2 TAP
- 33.3 CAPS
- 33.4 TAL
- 33.5 LSP
- 33.6 Infamous
- 33.7 ArtyFX
- 33.8 Calf
- 33.9 MDA
- 33.10 SWH
- 33.11 SAFE
- 33.12 Zam
- 33.13 x42
- 33.14 DISTRHO Mini-Series
- 33.15 Flo
- 33.16 hexD
- 33.17 LMMS
- 33.18 DPF Ports
- 33.19 Russolo
- 33.20 Ankh
- 33.21 NJL
- 33.22 Kapitonov
- 33.23 noise_factory
- 33.24 Freaked
- 33.25 CMT
- 33.26 mcfx
- 33.27 Invada
- 33.28 Shiru
- 33.29 ELE
- 33.30 ExEf
- 33.31 Creox
- 33.32 Louderbox
- 33.33 Mustajuuri
- 33.34 BetabugsAudio
- 33.35 si
- 33.36 Spaco
- 33.37 Airwindows
- 33.38 ScorchCrafter
- 33.39 Windows VST / macOS AU
- 33.40 to sort
to rework the headings
- linux-sound.org: Audio Plugin Systems For Linux
- linux-sound.org: VST/VSTi Plugins For Linux
- KVR Audio is a community and news site for popular Audio Plug-in formats and related subjects, such as sample libraries and mobile apps. Our mission is to supply up to date news to VST, AU, RTAS, DX and DSSI/LADSPA plug-in and iOS and Android App users in a friendly, up-front and timely manner.
- Alsaequal - a real-time adjustable equalizer plugin for ALSA. It can be adjusted using an ALSA compatible mixer, like alsamixergui or alsamixer. Alsaequal uses the Eq CAPS LADSPA Plugin as it's default equalizer but you can change it to use almost any LADSPA plugin, like mbeq from the swh-plugin package.
- jackEQ - intended to provide an accessible method for tweaking the treble, mid and bass of any JACK aware applications output. Designed specifically for live performance, it is modelled on various DJ mixing consoles which the main author Patrick Shirkey (aka DJ Kotau) has worked with live. LADSPA.
- NotNotchFilter - a performance-oriented filter designed to replace the mid-EQ found in a standard 3-band DJ mixer. The key advantage of this filter is that it cleanly cuts out single voices or instruments in a track, whereas a standard 3-band filter dampens them. This is because NotNotchFilter, as the name suggests, is not actually a notch filter. Rather, it is a combination of a hipass and lopass filter which work on opposite sides of the target frequency.
- HiLoFilter - a simple hipass and lopass filter which can be easily controlled with a single knob. It is loosely inspired by the same type of filter found on some Pioneer DJM mixers, and also the The Pilgrim, another great plugin which provides roughly the same functionality.
- x42-eq - a 4 band parametric equalizer with additional low+high shelf filters, Low and High-pass, as well as an optional, custom GUI displaying the transfer function and realtime signal spectrum or spectrogram. It is available as LV2 plugin and standalone JACK-application.
- Lv2fil - Stereo and mono LV2 plugins, four-band parametric equalisers
- EQ10Q - an audio plugin bundle over the LV2 standard (http://lv2plug.in) implementing a powerful and flexible parametric equalizer and more (gate)
- https://github.com/QuentinFAIDIDE/FutureEqualizer - Equalizer with a funny harmonic boost function. This eq computes harmonics from the 3rd peaking eq frequency with 4 Range Modes and let you tweak the gain and resonance as you want. Four modes are available using the range knob, first quarter: replicate 3rd filter one octave above, second quarter: replicate 3rd filter with a 3-notes major chord and one octave above, third quarter: replicate 3rd filter with a 3-notes minor chord and one octave above, last quarter: replicate 3rd filter one and two octave above.
- Luftikus - a digital adaptation of an analog EQ with fixed half-octave bands and additional high frequency boost. As an improvement to the hardware it allows deeper cuts and supports a keep-gain mode where overall gain changes are avoided.
- https://github.com/brummer10/GxMatchEQ.lv2 - Matching Equalizer to apply EQ curve from on source to a other source.
Frequency Response Correction
- Frequency Response Correction - Java. The program provides different filter functions to equalize the source signal in a way that it is linear in its frequency response after passing the room and its characteristics.
Audio Mastering Suite
- Audio Mastering Suite - Java, works for Windows, Mac and Linux. Features: - Native signal processing by using the resolution and sampling frequency of the source material. - The supported audio format is wav (PCM) 16/24Bit with 44.1kHz, 48kHz, 88.2kHz, 176.4kHz, 96kHz or 192kHz sampling frequency. - High quality resampling of any audio format into 16Bit/44.1kHz by applying "Bandlimited Interpolation". - 64Bit floating point signal processing. - The signal processing chain (order of components) is freely configurable. - Audio monitoring switchable between input and output signal.
- JAMin - the JACK Audio Connection Kit (JACK) Audio Mastering interface. JAMin is an open source application designed to perform professional audio mastering of stereo input streams. It uses LADSPA for digital signal processing (DSP)
- YouTube: 140_groove + jammin - audio routed through "Jammin".
- XO Wave - a digital audio workstation designed to meet the needs of audio and video professionals, with a focus on CD Mastering and audio for video work. XO Wave provides professional-grade capabilities for manipulating audio, with a familiar and elegant interface. Support for direct recording from any Core Audio device, importing and exporting files in a variety of formats (including songs from iTunes playlists), CD burning, multi-track editing, support for many Audio Units, and QuickTime synchronization and export, make XO Wave a great tool for all kinds of audio work, including podcasting, vodcasting, CD Mastering, mixing and more! Java.
- GCDMASTER - Easy and Powerful CD Mastering
- matchering - a novel Containerized Web Application and Python Library for audio matching and mastering.It follows a simple idea - you take TWO audio files and feed them into Matchering: TARGET (the track you want to master, you want it to sound like the reference) REFERENCE (another track, like some kind of "wet" popular song, you want your target to sound like it). Our algorithm matches both of these tracks and provides you the mastered TARGET track with the same RMS, FR, peak amplitude and stereo width as the REFERENCE track has.
- https://delamanchavst.wordpress.com/2013/10/24/fr33some - fr33some is a 3-band, stereo splitter. You can use it to define 3 frequency ranges for low, mid and high frequencies, and output each band to a different stereo output, for individual processing. Windows VST.
Windows / Mac
- https://vladgsound.wordpress.com/plugins/limiter6 - modular effect designed to limit dynamic range and to suppress peaks instereo and mono audio signals. Windows VST, macOS VST/AU.
Compression / limiting
- VLevel - a tool to amplify the soft parts of music so you don't have to fiddle with the volume control. It looks ahead a few seconds, so it can change the volume gradually without ever clipping. Because the volume is changed gradually, "dynamic contrast" is preserved.
- DPL1 - a look-ahead digital peak limiter, the kind you would use as the final step to avoid clipping when mastering or mixing. It can be used as an effect on individual instrument tracks as well. Latency is 1.2 ms rounded up to the nearest multiple of 8, 16 or 32 samples depending on sampling frequency. This amounts to 56 samples at 44.1 kHz, 64 samples at 48 kHz, and twice those values for 88.2 or 96 kHz.
- http://users.notam02.no/~kjetism/radium/compressor_plugin.php - The system compressor in Radium is also available as an independent audio plugin. The unique interface: Accurately visualize the sound compression. Rapidly helps you find good compressor settings. With the Radium Compressor, you spend less time listening and finetuning. The interface quickly makes you find the sound you want. Other Features: Top class audio quality. The DSP code is implemented by Julius O. Smith III. Julius O. Smith III is a professor in Music and EE at Stanford University, and he is one of the legends in audio research. The compressor is based on code Julius has written for Faust. OSS/$
- https://sourceforge.net/projects/molot/ LV2 and LADSPA versions of the Molot Lite compressor. "Molot Lite" is cut-down version of Molot compressor 0.3.
- https://github.com/magnetophon/CharacterCompressor - A compressor with character. A bit experimental: It works and sounds wonderfull, but has too many parameters, so is a bit fiddly to use. Also; I have no idea what to name the parameters, or how to explain a lot of them.
- Xhip Compressor - designed to loosely model a circuit I designed myself. It is like a pedal or what you might find in a channel-strip. It isn't designed to function as a limiter and it doesn't have instant response, look-ahead, low distortion or any of that stuff. That is exactly what makes it useful.
- Xhip Limiter - A counterpart to the compressor for limiting with the most simple design possible. This limiter is designed for maximal sustain and minimal distortion. It aims to be as transparent as possible in terms of timbre without using any advanced techniques.
x42-limiter / dpl.lv2
- x42 Digital Peak Limiter - (aka dpl.lv2) is a look-ahead digital peak limiter based on Fons Adriaensen's DPL-1. It is intended to be used as final step to avoid clipping when mixing or mastering, but can also be used on individual tracks as well. It comes in mono and stereo variants, the stereo version applies the same gain reduction to both channels. Latency is 1.2 ms, rounded up to the nearest multiple of 8, 16 or 32 samples depending on sampling frequency. This amounts to 56 samples at 44.1 kHz, 64 samples at 48 kHz, and twice those values for 88.2 or 96 kHz.
- https://github.com/x42/darc.lv2 - a general purpose audio signal compressor.The compression gain is controlled by threshold and ratio only: Makeup gain is automatically set to maintain equal loudness at -10 dBFS/RMS with a soft knee. It is available as LV2 plugin and standalone JACK-application.
- LazyLimiter - A clean yet fast lookahead limiter written in Faust. It uses somewhat of a 'brute force' algorithm , so it's quite CPU-hungry.
- https://github.com/magnetophon/CompBus - A group of compressors mixed into a bus, sidechained from that mix bus.It can have any number of compressors with any number of channels per compressor.
Audio Compressor & Limiter
- Audio Compressor & Limiter - Java
- https://github.com/DanielRudrich/SimpleCompressor - Code and theory of a look-ahead compressor / limiter.
- RoughRider3 - one of the most popular dynamics processors on the planet, with well over a half a million downloads over its decade-plus lifespan, and is in heavy daily use by producers the world over. With Audio Damage's RoughRider3, the original is to include an external sidechain input, the ability to turn off the built-in "warming" filter (the FULL BANDWIDTH button), and much more accurate metering.
- https://github.com/mzuther/Squeezer - Flexible general-purpose audio compressor with a touch of citrus
- nova67p - a parallel parametric equalizer plugin combined with a compressor. The compressor can optionally operate in frequency dependent and split-band modes. In this case the plugin operates as a parallel dynamic equalizer.
- https://delamanchavst.wordpress.com/2013/11/20/sixtyfive-compressor-dbx-165a-style-is-now-free/ sixtyfive is a vintage-style, RMS Compressor, inspired by the dbx® 165A, a classic 1970’s compressor found in many studios, but it also adds a couple of new twists. It’s a soft-knee RMS compressor with a vintage flavour. The RMS detection and soft-knee help to give a smooth and musical compression experience, the non-linear response imparts character and the gentle saturation brings colour and warmth. As well as all of the originals features, this version adds parallel compression, extended knob ranges and peak metering
- GTA - a vintage style ‘character’ compressor, designed like its muscle car name-sake for brute power, pure speed and to make a loud noise. It is stripped down for ease of use and has a unique vintage colouring on top.
Rough Rider 2 Compressor
- Rough Rider Compressor - a modern compressor with a bit of "vintage" style bite and a uniquely warm sound. Perfect for adding compression effects to your drum buss, it also sounds great with synth bass, clean guitar, and backing vocals. Definitely not an all-purpose compressor, Rough Rider is at its best when used to add pump to rhythmic tracks. Rough Rider is available as both 32- and 64-bit VSTs for Windows, and as a Universal Binary AU/VST for OSX.
- OTT - a free re-creation of a popular aggressive multiband upwards/downwards compressor set-up used by many dubstep and electro producers, by Xfer Records
- W1 Limiter - a clone of Waves L1, with identical output, as well as an approximation of Waves L2.
- abGate - a LV2 noise gate plugin in the LV2 format to manage noise. A noise gate is a component which attenuates an audio signal when it falls below a set threshold, so it can be applied to an audio track which has one or more periods of silence where no noise should be apparent.
- Xhip Gate - A gate effect including side-chain input and a few other additional features. Ideally the trigger/threshold detector and envelope generator would be separate plug-ins, although this is not so practical in the majority of cases. Instead a general-purpose AhR envelope is used.
GT10QM / GT10QS
- GT10QM / GT10QS - Versatile noise-gate plugin with mono (M) and stereo (S) versions. This plugin provides the usual controls in a dynamic gate processor: threshold, range, attack, release and hold. But also features some extra parameters to allow an accurate adjustment. The gain control is useful to bring the input sound level in the correct VU meter range to be able to tune the threshold right. Even though the internal processing is performed in floating point at 32 bits, it’s helpful to adjust the input gain in a standard range to achieve an optimum level visualization. Together with VU meter, there is also a gain reduction meter that aids to set up the controls. Besides the power of dynamic section controls (DYN), there is also a filtered side chain section (SC). Here it is possible to adjust a low pass filter (LPF) and a high pass filter (HPF) and listen the actual side chain signal after filtering with the “Key” button. This side chain flexibility is very interesting to avoid unwanted noises to start triggering the gate.
- https://github.com/rghvdberg/gator - Developing a programmable gate plugin using DPF
- https://github.com/ycollet/psi-plugins - midi_gate: an enveloped stereo MIDI gate, sidechain_gate: stereo sidechain gate (with hysteresis) based on Steve Harris's Gate plugin
- https://github.com/sonejostudios/SuperCutSequencer - Cut "On/Off" Sequencer (8 steps with smooth) synced to Midi-Clock Beats and Midi-Clock Start/Stop
- https://github.com/jeremysalwen/Stutter-LV2 - This is a simple plugin for creating a "stuttering" effect for your audio. It is in the LV2 format.
- moot - a flexible audio mute plugin with a number of additional features. The mute switch (Hit Me) can be assigned to a single midi keyboard key and act in 3 ways: as a latch (one press mute, release stays muted, next press unmute, release stays unmuted), in default mode (hold down to mute, release to play audio), in invert mode (hold down to play audio, release to mute). Windows VST2.
- gator - creates a random steppy, gated effect, triggering volume between 2 adjustable values by a tempo-sync'd probability-based step sequencer. An LFO can modulate the volume when triggered and trigger pulse length, attack and release can shape the sound. Windows VST2
- StormGate1 - an unique and innovative amplitude rhythmic gating effect which lets you draw the gating patterns freely by hand or with the aid of powerful drawing tools. PC VST format and MAC VST and AU formats.
- A1TriggerGate - "There are many sequenced / rhythmic gates out there, but honestly nothing really satisfied me yet. So I decided to write my own plugin for this task..." - Windows/Mac
Calf Vintage Delay
- Calf Vintage Delay - based on bpm-oriented delay time settings. Additionally the delayed signal is processed by a filter to simulate old tape-machine based delay effects. Some options of the stereo distribution of the delayed signal makes it very flexible and wide-ranged in sound.
- TAL-Dub - a vintage style delay effect. It can be used for a wide range of delay effects from clean to extreme distorted, resonating never ending delays :-)
TAL-DUB-II is an extended version of TAL-Dub-I with a completely new sound engine. A 4x oversampled distortion stage allows to add vintage distortion to the delayd signal, but its also possible to make clean delays. A sinus LFO has the possibility to modulate delay time and low pass filter cutoff. Adjustable LFO stereo width is also included. An analog sounding 6dB low pass filter with resonance and a 3dB high cut filter are also parts of TAL-DUB-II. Different routing options open a wide range of possibilities.
TAL-DUB-III is an easy to use delay device with some special features. Its no tape delay emulation and has its own sound. It has an alias free saturation stage, a non-linear 6dB low pass and a 3dB high pass filter that are included in the feedback path of the device. An input drive knob allows to adjust the saturation level. Pop-up menues show the current values of volume, delay-time and feedback knobs. A tab button allowing to adjust the delay time for live sessions.
- https://github.com/WolfSound/MidSide - MS Delay/Mixer VST plug-in. It can be use for widening effects of an input stereo signal.
- Xhip mDelay - dual delay with stereo, cross and ping-pong modes. It has an LFO and can be used to create anything from flangers and chorus to ordinary delays and strange detuned echos all the way up to extreme pitch modulation effects.
- https://github.com/qbroquetas/IV-XDelay - a free and open source delay VST effect modelled after a renowned vintage tape recorder. Its aim is to provide music producers with a fun and useful tool that sounds and works like vintage tape echo boxes, as well as to serve as an educational tool for anyone interested in audio development and digital signal processing.
- https://github.com/MrBollie/bolliedelayxt.lv2 - The evolution of my bolliedelay.lv2, features full control over two seperate channels, HPF/LPF on both, the delay path and feedback path, fractional delay, that enables modulation
- https://github.com/tesselode/cocoa-delay - a free, open-source delay plugin in VST format. It focuses on clean design, easy operation, and a warm, lively sound.Notable features: Delay time drift, for giving the wet signal a slight wow/flutter effect; Adjustable wet level ducking based on the input signal; Static, ping-pong, and circular pan modes; Drive section based on open-source Airwindows saturation code
- Pitched Delay - kvraudio.com DC12 entry.
- BOWECHO - Quad Modular Delay. Use the key R7P1R64720175164548606433 to unlock the demo version. OS X, Windows and Linux.
- YouTube: SevenDelay Demo
- https://github.com/linuxmao-org/regrader - A delay effect where the repeats degrade in resolution (unofficial port)
- https://github.com/unclechu/faust-channel-delay - Faust DSP for delay channels independently.
- Tapiir - a simple and flexible audio effects processor, inspired on the classical magnetic tape delay systems used since the early days of electro-acoustic music composition. It provides a graphical user interface consisting of six delay lines, or "taps", which can introduce an almost arbitrarily big or small delay to their inputs and can be feed back to each other. A wide set of effects can be easily achieved by properly configuring and connecting the delay lines: complex echo patterns, resonances, filtering, etc. Delays, interconnections and gains can all be controlled in real time.
- Tom Pong is a ping pong delay VST Plugin. Windows only. A ping pong delay is a delay which alternates from one speaker to another. If the balance is set to 0.5, a stereo signal will invert itself each time the delay buffer is played back. If the balance is set to either side of 0.5, the signal bounces back and forth between the speakers. Tom Pong can be synced to the host sequencer, or delay times can be set by sample count. Feedback and output level are also adjustable.
- combover - a comb delay, and four more comb delays, and a step sequencer that does odd things, and a pool of prime numbers that make stuff happen, and some mix n match pitch detection. It also has an xy pad and wet / dry controls that let some stuff through and other stuff not. It does crazy stuff, you should stop reading these words and find out for yourself.
- https://www.fullbucket.de/music/fbdelay.html - windows vst
- YouTube Classic Delay by Kjaerhus Audio
- Spaceship Delay is a delay audio effect featuring classic modern and vintage sounding delays
- https://www.kvraudio.com/kvr-developer-challenge/2016/#dc16-12755 - Windows/Mac only
- Regrader - provides a delay effect in which the repeats degrade in various ways to provide a malevolent twist on the ears.Echoes disintegrate, are decimated, piercingly oscillate and are finally mangled into a sound reminiscent of a jet engine processing gravel. Each of the modules within Regrader have different routing possibilities to finely tune your carefully sculpted noise. Think industrial or dark sound design to find a purpose for the plugin or see what others say.
- Shoegaze VST - Features: reverse delay, a staple of shoegaze, feedback, minimal interface, no DRM, For Windows only.
- Cocoa Delay - a free, open-source delay plugin in VST format. It focuses on clean design, easy operation, and a warm, lively sound.
See also #Convolution
- Multiverb is an audio plug-in that produces a reverb effect on a monaural or stereo audio track. It is available as both a VST plug-in for Windows (Win32 and Win64) and an LV2 plug-in for Linux. Multiverb implements an acoustic system that is an interconnection of multi-port acoustic elements. For a full technical description of the Multiverb algorithm please see my paper in the Journal of Multidisciplinary Engineering Science and Technology (JMEST).
- https://github.com/professorwub/MultiverbLV2 - doesn't build? lv2-plugin
- https://github.com/michaelwillis/dragonfly-reverb - A hall-style reverb based on freeverb3 algorithms
- mverb - Studio quality, open-source reverb. Its release was intended to provide a practical demonstration of Dattorro’s figure-of-eight reverb structure and provide the open source community with a high quality reverb.
- REV1 - a reworked version of the reverb originally developed for Aeolus. Its character is more 'hall' than 'plate', but it can be used on a wide variety of instruments or voices. It is not a spatialiser - the early reflections are different for the L and R inputs, but do not correspond to any real room. They have been tuned to match left and right sources to some extent.
- https://sourceforge.net/projects/zitzreverb/ - forkish?
- KR-Reverb FS - an easy to use Reverb processor based on features found on our commercial product KR_Space. KR-Reverb FS is designed for ease of use by adjusting internally the equalization and damping controls to optimal levels for producing a warm reverb sound suitable for a wide range of applications.
- Protoverb - an experimental reverb based on the idea of a "room simulator". Most algorithmic reverbs try to avoid resonances or model the reflections of sound from a rooms walls. Protoverb does the opposite. It builds up as many room resonances as possible, modeling the body of air in the room. It therefore does not need to modulate or colour the signal. The result is a very natural sounding reverbration with some interesting features: Long standing frequencies resonate louder, as if the air takes some time to get excited. Multiple instruments don't mash into a diffuse mud, they stay distinct. If you play a short melody, the room seems to repeat a ghost echo of that melody. Those properties are indeed found in churches and large halls, but they're rarely found in conventional algorithmic reverbs.
- https://github.com/linuxmao-org/fogpad - A reverb effect in which the reflections can be frozen, filtered, pitch shifted and ultimately disintegrated (unofficial port)
- Xhip Reverb - A reverb effect designed to avoid an ultra-smooth fade-to-noise decay.
- Teufelsberg Reverb - Put the sound of cold war surveillance into your music. Convolution.
- Kushview - Create Creepy Robotic Effects, Schroeder Reverb - AU/VST/VST3/LV2
- https://github.com/coreyker/KBVerb - Faust reverb
Sostenuto, "infinite sustain"
- Infamous Plugins: Stuck - a clone of the electro-harmonix freeze. It drones the note being played when the "Stick It!" port is set to 1 (or the CV port input goes above 1), causing the note to be "stuck". Once the port falls below 1 the drone is released with a decay set in seconds. The drone is added to the dry signal (so original signal is passed through at all times un-processed). This plugin is pretty useless except in live situations, though I'd love someone to creatively prove me wrong.
- Richter - a two LFO tremolo, the interaction of which creates far more complex volume oscillations than can be created with a single LFO. The rate and depth controls of each LFO can each be modulated by two more LFOs to create variations in frequency and depth, and tempo sync is available on all oscillators. VST, VST3, and Audio Unit, Windows, Mac, and Linux.
- https://github.com/dsheeler/tremelo.lv2 - an audio-plugin in LV2 format that modulates the amplitude of the input signal. The modulation is sinusoidal with adjustable amplitude and frequency.
- Xhip Tremolo - a standard tremolo with the addition of a couple features. One is that it has phase adjustment for the LFO, allowing it to produce a "wide" tremolo panning effect. Second is that the waveform can be adjusted between pulse-like, linear and saturated which produce different characters mimicking various old tremolo effects.
- https://github.com/Houston4444/plujain-ramp - Rhythmic tremolo LV2 plugin
- Flutterbird - a free, open-source effect plugin for adding pitch and volume fluctuation to incoming audio. It can be used for traditional wow/flutter effects as well as more chaotic, extreme modulation. Flutterbird has four separate oscillators with adjustable speeds that can be mapped to either pitch or volume.
- https://www.meldaproduction.com/MTremolo - VST, VST3, AU and AAX interfaces on Windows & Mac, both 32-bit and 64-bit
- https://github.com/jkbd/scannervibrato - A LV2 plug-in for the Chorus or Vibrato modulation effect used in different tonewheel organs. Based on a physical informed model implemented in Faust.
- Xhip Phaser - standard phaser effect with a variable number of stages. This phaser doubles as a frequency dependent delay, chorus effect and vibrato because it allows you to use up to 128 stages.
- https://github.com/jpcima/stone-phaser - A classic analog phaser effect, made with DPF and Faust
- https://github.com/jpcima/stone.lv2 - initial test
- https://sourceforge.net/projects/teliasopia - Lv2 plugins with GUI
- vm.lv2 - various plugins with a programmable stack-based virtual machine to modify up to 8 LV2 Control, CV, Audio, Atom and MIDI signals. To be used when that specific simple filter plugin you desperately need does not yet exist.
- https://github.com/jd-13/Songbird-Formant-Filter - Songbird is a modulated vowel/formant filter. Select two vowels and then modulate between them using either the manual slider or the LFO. There are five vowel sounds and two modulation modes available to choose from. The "freq" modulation mode allows you to modulate a single filter between the two vowels chosen, to create a powerful vocal sound. The "blend" mode provides a more subtle effect, modulating the mix between two parallel filters. Songbird is ideal for creating both vocal bass sounds and subtle filter sweeps.
- Xhip Vocal - A simple phoneme synthesizing filter made from several parallel formant filters. This filter provides AEIOU formants with control over center frequency and Q with smooth interpolation between formant sets with the phoneme control.
- https://github.com/pdesaulniers/wolf-lfo - Multi-FX LFO plugin (VST, LV2 and Jack)
- https://github.com/QuentinFAIDIDE/FutureLowCut - Old Low-Cut LV2 Audio Filter Plugin
- https://github.com/igorski/transformant - VST plugin that acts as a multi channel formant filter
- https://github.com/dozius/DtBlkFx - a Fast-Fourier-Transform (FFT) based VST plug-in.
- https://github.com/jpcima/rezonateur - Virtual-analog 3-band resonator
- https://github.com/sufystudios/LV2LPFMassberg - simple low pass filter using biquad.
Windows VST / Mac
- sfilter - creates a stepped filtered sequence, to create gating, sweeps or rhythmic modulation of filter cut-off. It uses a variable state filter, varying between 2 adjustable cut-off values according to a tempo-sync’d step sequencer. An LFO can also modulate the filter for extra movement
- pfilter - creates a steppy, gated effect, but using filter cut-off instead of volume to give a wider range of possibilities. It uses a variable state filter, triggered between 2 adjustable cut-off values by a tempo-sync’d probability-based step sequencer. An LFO can modulate the filter when triggered and trigger pulse length, attack and release can shape the sound
- sumo - an effect plugin to make any sound as fat as you like. It’s good for fattening up leads and basses, adding some weight to pads, making your vocals chubby and your drums obese
- DtBlkFx - a freeware Fast-Fourier-Transform (FFT) based Multi effect VST plug-in for Windows and Mac. Precision parametric equalizing with sharp-roll off, adjust individual harmonics of a sound. Harmonic based (or comb) filtering, including active harmonic tracking. Various types of noise control, change contrast between loud and soft frequencies, clip frequencies or apply sound smearing. Frequency shifting, harmonic and non-harmonic shifting, including active harmonic repitch.
- DvnKeyFilter - Give more expressiveness in your monophonic melodic lines with DvnKeyFilter!! It's a low pass filter with the cutoff frequency controlled by key tracking and a second parameter "Expression" assignable to any midi cc (or disable it and use your DAW envelope).
- Soundemote: Flower Child Filter - aptly named for its goal to have a clean and resonant sound. There is also a switch for an aggressive growling version that is sure to cater to your more destructive side.
- You Wa Shock ! - VST/Winamp effect to brighten up and maximize any truck you hand it.
- https://github.com/Umcaruje/tfchorus - an LV2 and LADSPA port of TF Chorus by TraumFlug. The great, unique chorus effect was found in the Armstrong package of an old PPA. Any information about this plugin seems to have disappeared from the internets. There was no license, except that it is implied to be "free, open source software" (see src/tfcho_orig.cpp, the original source) and that the rest of Armstrong is released under GPLv2. For now let's say this port is under the same license as the original, whatever it may be.
JPC Ensemble Chorus
- https://github.com/jpcima/ensemble-chorus - Digital model of electronic string ensemble chorus
- https://github.com/SpotlightKid/ykchorus - A chorus audio effect plugin based on DSP code by Togu Audio Line (TAL), inspired by the one found in certain well-known Japanese vintage analog synthesizers (You Know which).
- https://github.com/BramGiesen/ringModulator_lv2 - A simple LV2 example in C++. Just for experiments.
- https://www.meldaproduction.com/MRingModulator - performs classic ring-modulation effects using one or two oscillators. With a clean interface that gives easy access to more advanced controls like our adjustable phase difference and shape features, including editable custom waveforms and harmonics.
- ring thing - a multi-flavour ring modulator, with frequency and mix level controlled by an XY pad and each axis modulated by it’s own tempo-sync LFO. The modulation in both axes is shown graphically on the XY pad.
- Wolf Shaper - a waveshaper plugin with a graph editor. It passes the input signal through a function, which you can design using curves. This processing results in a more harmonically rich signal.
- https://github.com/sjaehn/BShapr - Beat / envelope shaper LV2 plugin
- https://github.com/nickolas360/waveshaper - powerful LV2 waveshaper plugin.
- https://www.meldaproduction.com/MWaveShaper - goes beyond a traditional wave-shaping plugin. Unlike the conventional approach of providing a few predefined patterns, MWaveShaper lets you construct your own shape creating a much greater range and control over your sound.
- https://www.meldaproduction.com/MWaveFolder - an analog-inspired distortion module with a unique character ranging from mild harmonic enhancement to complete sound destruction.
- https://www.meldaproduction.com/MComb - an extremely powerful multi-comb filter plugin. Using its 2 extremely versatile modulators it becomes a powerful processor, which can follow a simple LFO, react to input levels, MIDI note, input pitch...
- SDRR - built to satisfy almost all of your saturation desires. It provides a comprehensive set of controls to manipulate the character of the saturation to make it fit exactly. SDRR offers four different main modes: TUBE, DIGI, FUZZ, DESK and reacts dynamically to the input signal. Each mode has its unique crosstalk behavior, which can be switched off or exaggerated. A unique RMS level difference metering mode makes level matching an easy task. SDRR can be different things: a saturation, a compressor, an EQ, a bit-crusher, a subtle stereo widener, or simply add some movement to your tracks with the DRIFT control. Add warmth, depth and character to your tracks with SDRR.
- IVGI - can deliver very soft and subtle saturation, that feels at home on the master buss. It is equally capable of very dense and dirty distortion effects to spice up single tracks. IVGI's base sound is comparable to the DESK mode in the big brother SDRR. Windows/Mac VST.
- https://github.com/naptastic/nap-smash.lv2 - LV2 saturation plugin
- http://x42-plugins.com/x42/x42-whirl - x42-whirl is a designed to imitate the sound and properties of the electromechanical rotating speaker device that brought world-wide fame to the name and products Don Leslie. It is a standalone version of the effect that came to be with the setBfree synth. Rather than simulating the net effect of the electromechanical device, x42-whirl physically models the properties, which results in very accurate representation of the sound of the real device. Since all individual parts are modelled, x42-whirl not only provides advanced control, but also facilitates customizations, some of which are not feasible in the mechanical device.
- Arcangel - a jack effect for arctan distortion. Sounds nice and grungy without clipping at high levels, and sounds nice at lower levels.
- https://github.com/moddevices/mod-distortion - Analog distortion emulation developed by mod team (lv2). The effects were developed suposing you have a -15dB input signal (measured with digital peak meter) when you play loud, so its recommended that you ajust your input gain to this level. We recommend that you use only the stable plugins: -DS1 -Big Muff Pi
- https://github.com/moddevices/gx_vobtb.lv2 - Fuzz Tonebender plugin
- https://github.com/LiamLombard/DS1.lv2 - Simulates a Boss DS1 distortion pedal.
- https://github.com/jpcima/quadrafuzz.lv2 - Multi-band fuzz distortion plugin
- Jk-drive - The plugin does basic wave shaping distortion with 2x oversampling. It produces both even and odd order hamonic distortion.
- deteriorate-lv2 - A set of plugins to deteriorate the sound quality of live inputs. The set contains two plugins: A basic granulator, a basic downsampler
- YouTube: deteriorate-lv2 - demo
- Deathcrush is a distorsion plugin, made up of some raw effects (such as bitcrusher and compressor) to really ruin your gentle sounds.
- https://github.com/unclechu/lv2-ladspa-bit-crusher - Bit Crusher Audio Plug-In (LV2 and LADSPA)
- https://github.com/grejppi/bitrot - A set of LV2 and LADSPA plugins for glitch effects
- WubFlip - It sort of flips high or low values beyond a threshold making a dirty distorted mess of the sound that might be useful for people making wanting big dirty breaks or synths or something like that. Play around with the sliders. The upper threshold slider needs to be higher (to the right of) than the lower threshold slider otherwise you'll get no sound. The difference between them effects the sound. Then the multiplier slider effects how much "flipping" gets done. LADSPA.
- Carve - a wave shaping distortion with several available waveforms and two distortion units, which can be configured in serial, parallel or stereo, and blended with the dry sound. VST, VST3, and Audio Unit, Windows, Mac, and Linux
- Danaides - Sequenced Sound Mangler
- Misstortion VST by Nimble Tools - Does its best to be like Logic's Clip Distortion, which makes it very useful for the Hardstyle genre. Hard clip: Simple hard clip distortion. Soft clip: Hyperbolic soft clip distortion. Symmetry: Make your waveform asymmetrical for more finetuned distortion.
- https://github.com/pdesaulniers/misstortion - Fork of Misstortion that allows building it as an LV2 plugin
- https://github.com/creativeintent/temper - a digital distortion audio plugin targeting VST, VST3, and AU for OS X and Windows. It builds upon traditional waveshaping techniques using modulated filter coefficients to produce a unique phase distortion. The primary signal processing loop is written with Faust, and compiled with JUCE for the various build targets.
- Gorgon - Distortion. Glitchmachines Subvert is the evolution of Gorgon. The download contains the unlocked installers. OS X and Windows.
- https://www.meldaproduction.com/MBitFun - a serious tool for extreme distortion lovers. It converts the audio into limited fixed-point precision form, from a 1 single bit up to 16 bits per sample, and lets you access each bit, applying several operations.
- FuzzPlus3 - vintage fuzz pedal model, plus a new filter, self-feedback, and a modern procedural user interface. Windows/Mac
- thrummaschine - a 3-band distortion effect with independant, LFO-driven filters. Make your bass, mid and high frequencies oscillate at different speeds, shapes and pan, with whatever flavour and level of distortion you dial in for each band
- Imperfection - an effect plugin to put some lofi back into your pristine 64bit audio. Who wants hi fidelity reproduction when you can reduce the quality, take out some of that bottom end, add a smear of saturation and bring your noise floor back up. Hmmm, perfectly imperfect
- bent - a circuit-bent resynthesis effect. It will recreate the incoming audio into an approximation of itself using a waveform-morphing audio oscillator. Depending on the volume and pitch of the audio, it will gate, stutter and morph the output in sync with your host tempo
- freq show - screws around with your audio and ouputs an unholy version of whatever you fed it
- GClip - Free VST wave-shaping signal clipper. Clip peaks off audio with abrupt or smooth wave-shaping. Graph and waveform displays assist in setting the clip level according to the source material. Oversampling can be enabled to reduce aliasing.
- DvnBitCrusher - It's a bit crusher effect that offers sample rate reduction down to 200Hz, bit depth reduction, distortion unit and low pass filter, dry/wet mix and gain stages at the input and output.
- https://github.com/zamaudio/zamvalve - Valve distortion plugin. Faust >=0.9.62 and LADSPA SDK is required to compile this LADSPA plugin.
- Frequency Shifter - a VST™2.4 software effect for Microsoft Windows® written in native C++ code. Frequency shifting up to ±5000 Hz. Optional LFO with five waveforms. Four frequency ranges, three mix modes.
- https://www.meldaproduction.com/MFreqShifter - an extremely versatile frequency shifter. Unlike pitch-shifters it doesn't keep harmonic relationships and can provide everything from mild stereo expansion to complete sonic destruction.
- Autotalent began as the result of a week of recreational signal processing in May 2009. It's a real-time pitch correction plugin. You specify the notes that a singer is allowed to hit, and Autotalent makes sure that they do. You can also use Autotalent for more exotic effects, like the Cher / T-Pain effect, making your voice sound like a chiptune, adding artificial vibrato, or messing with your formants. Autotalent can also be used as a harmonizer that knows how to sing in the scale with you. Or, you can use Autotalent to change the scale of a melody between major and minor or to change the musical mode. LADSPA.
- talentledhack - an LV2 port of Tom Baran's Autotalent, with added features and improved performance.
- AT1 - an 'autotuner', normally used to correct the pitch of a voice singing (slightly) out of tune. Compared to 'Autotalent' it provides an improved pitch estimation algorithm, and much cleaner resampling. AT1 does not include formant correction, so it should be used to correct small errors only and not to really transpose a song. The 'expected' pitch can be controlled by Midi (via Jack only), or be a fixed set of notes. AT1 can probably be used on some instruments as well, but is primarily designed to cover the vocal range. It's also usable as a quick and dirty guitar tuner.
- https://sourceforge.net/projects/zitaretuner/ - 'fork' of above
- x42-autotune - aka fat1.lv2, is an auto-tuner based on Fons Adriaensen's zita-at1. The main differences to zita-at1 are that the LV2 plugin version reports its latency to the host, saves the state with the session and the MIDI input has sidechain semantics.
- TAL-Vocoder is a vintage vocoder emulation with 11 bands that emulates the sound of vocoders from the early 80’s. It includes analog modeled components in combination with digital algorithms such as the SFFT (Short-Time Fast Fourier Transform). This vocoder does not make a direct convolution of the carrier and modulation signal as other digital vocoders maybe do. It includes an envelope follower for every of the eleven bands. This vocoder is optimized for voice processing and includes some algorithms for consonants to make the voice more intelligible. The carrier signal is a VCO (Voltage Controlled Oscillator) with a Pulse, Saw, Noise and SubOsc. But it’s also possible to use the left stereo input as carrier. This way every sound source can be used as carrier signal.
- vocoder (JACK standalone). It's a complete rewrite of the old vocoder, now done in C++ using FLTK.
- VocProc - an LV2 plugin for pitch shifting (with or without formant correction), vocoding, automatic pitch correction and harmonizing of singing voice.
- mod-pitchshifter - Pitch Shifter lv2 effects
- https://github.com/magnetophon/VoiceOfFaust - Turns any monophonic sound into a synthesizer, preserving the pitch and spectral dynamics of the input. The name was chosen because I use it mostly to turn my voice into a singing robot, and it's made in Faust.
- PitchBox - a small software application for transforming your voice or music in real-time. PitchBox was developed for shows and exhibitions, and was hence tuned for that purpose. As such, most of the efforts have been done in proposing ear-catching and attractive audio effects, and on reducing the latency as much as possible. On the other hand, fewer efforts have been done in making it easy to install and setup, or in the amount of features it provides. If you want to use the audio effects of PitchBox within an audio editor, most of them are available as LADSPA and VST plugins.
- https://github.com/maxwellpollack/repitch - real-time polyphonic MIDI-controlled audio pitch shifting
- https://github.com/seungwonpark/melgan - Unofficial PyTorch implementation of MelGAN vocoder (compatible with NVIDIA/tacotron2)
- Vintage Vocoder - real-time audio effect - VST and DXI plug-in for PC/MAC. Originally a commercial product published by Sonicism Digital Audio Solutions in 2002. This software was used for the robot voices and sound effects in the computer game Freelancer.
- GVST - GSnap - Free VST pitch-correction. Use with subtle settings to nudge off-key vocals back in line. Extreme settings can create sounds like the famous T-Pain or Cher effect. MIDI control mode allows you to fit a recording to a new melody.
- La Voz Cantante - a 512 channel vocoder. The modulator input - usually a sung or simpjy spoken voice - is analyzed with respect to its spectral content, which is then applied to the other sound source. The latter may be any externally supplied signal ranging from pink noise, synth pads, guitar or even drums. Alternatively, there is an internal, MIDI driven synth which is optimized for best speech reproduction fidelity. You can blend the high frequencies with noise for more natural sounding plosives and fricatives. Threre is also a noise gate, a compressor and a stereo reverb on board.
Windows / VST
- MIDI Choir - will take a single-pitched audio source and transpose it in real time according to the supplied MIDI notes. My main motivation to create MIDI Choir was to be able to sing harmonies live, however the product may also be used for studio work
- https://en.wikipedia.org/wiki/Phase_vocoder - a type of vocoder which can scale both the frequency and time domains of audio signals by using phase information. The computer algorithm allows frequency-domain modifications to a digital sound file (typically time expansion/compression and pitch shifting). At the heart of the phase vocoder is the short-time Fourier transform (STFT), typically coded using fast Fourier transforms. The STFT converts a time domain representation of sound into a time-frequency representation (the "analysis" phase), allowing modifications to the amplitudes or phases of specific frequency components of the sound, before resynthesis of the time-frequency domain representation into the time domain by the inverse STFT. The time evolution of the resynthesized sound can be changed by means of modifying the time position of the STFT frames prior to the resynthesis operation allowing for time-scale modification of the original sound file.
- pvc - PVC is a collection of phase vocoder signal processing routines and accompanying shell scripts for use in the transformation and manipulation of sounds. It is written in C and designed to be used in a UNIX environment.
- pv in WaoN project is yet another phase vocoder implementation for my understanding of the process behind WaoN and others. Here is what you can do: time streching/shrinking without pitch changing (by rate option) and pitch shifting without time streching (by pitch option)
- pvoc is a collection of LADSPA units and a command line tool for time compression/expansion of sound data making use of the phase-vocoding technique.
- https://github.com/lucianodato/noise-repellent - An lv2 spectral noise reduction plugin.
- https://github.com/lucianodato/speech-denoiser - A speech denoise lv2 plugin based on Xiph's RNNoise library. RNNoise is a library that uses deep learning to apply noise supression to audio sources with voice presence. 
- https://github.com/chaserhkj/jack-aec - Acoustic echo cancellation for Jack Audio, using WebRTC AEC library
Response and convolution
kinda messy section
- https://en.wikipedia.org/wiki/Frequency_response - the quantitative measure of the output spectrum of a system or device in response to a stimulus, and is used to characterize the dynamics of the system. It is a measure of magnitude and phase of the output as a function of frequency, in comparison to the input. In simplest terms, if a sine wave is injected into a system at a given frequency, a linear system will respond at that same frequency with a certain magnitude and a certain phase angle relative to the input. Also for a linear system, doubling the amplitude of the input will double the amplitude of the output. In addition, if the system is time-invariant (so LTI), then the frequency response also will not vary with time. Thus for LTI systems, the frequency response can be seen as applying the system's transfer function to a purely imaginary number argument representing the frequency of the sinusoidal excitation. Two applications of frequency response analysis are related but have different objectives.
For an audio system, the objective may be to reproduce the input signal with no distortion. That would require a uniform (flat) magnitude of response up to the bandwidth limitation of the system, with the signal delayed by precisely the same amount of time at all frequencies. That amount of time could be seconds, or weeks or months in the case of recorded media. In contrast, for a feedback apparatus used to control a dynamic system, the objective is to give the closed-loop system improved response as compared to the uncompensated system. The feedback generally needs to respond to system dynamics within a very small number of cycles of oscillation (usually less than one full cycle), and with a definite phase angle relative to the commanded control input. For feedback of sufficient amplification, getting the phase angle wrong can lead to instability for an open-loop stable system, or failure to stabilize a system that is open-loop unstable. Digital filters may be used for both audio systems and feedback control systems, but since the objectives are different, generally the phase characteristics of the filters will be significantly different for the two applications.
- https://en.wikipedia.org/wiki/Transient_response - the response of a system to a change from an equilibrium or a steady state. The transient response is not necessarily tied to abrupt events but to any event that affects the equilibrium of the system. The impulse response and step response are transient responses to a specific input (an impulse and a step, respectively).
- https://en.wikipedia.org/wiki/Impulse_response - impulse response function (IRF), of a dynamic system is its output when presented with a brief input signal, called an impulse. More generally, an impulse response refers to the reaction of any dynamic system in response to some external change. In both cases, the impulse response describes the reaction of the system as a function of time (or possibly as a function of some other independent variable that parameterizes the dynamic behavior of the system). In all these cases, the dynamic system and its impulse response may be actual physical objects, or may be mathematical systems of equations describing such objects.
- https://github.com/x42/jack-ir - a standalone JACK application to conveniently capture impulse responses of external devices using the commandline.
- Aliki - an integrated system for Impulse Response measurements, using the logaritmic sweep method developed by Prof. Angelo Farina.
- DRC - a program used to generate correction filters for acoustic compensation of HiFi and audio systems in general, including listening room compensation. DRC generates just the FIR correction filters, which can be used with a real time or offline convolver to provide real time or offline correction. DRC doesn't provide convolution features, and provides only some simplified, although really accurate, measuring tools.
- REW - free room acoustics analysis software for measuring and analysing room and loudspeaker responses. The audio analysis features of REW help you optimise the acoustics of your listening room, studio or home theater and find the best locations for your speakers, subwoofers and listening position. It includes tools for generating audio test signals; measuring SPL and impedance; measuring frequency and impulse responses; measuring distortion; generating phase, group delay and spectral decay plots, waterfalls, spectrograms and energy-time curves; generating real time analyser (RTA) plots; calculating reverberation times; calculating Thiele-Small parameters; determining the frequencies and decay times of modal resonances; displaying equaliser responses and automatically adjusting the settings of parametric equalisers to counter the effects of room modes and adjust responses to match a target curve.
- https://en.wikipedia.org/wiki/Convolution - In acoustics, reverberation is the convolution of the original sound with echoes from objects surrounding the sound source. In digital signal processing, convolution is used to map the impulse response of a real room on a digital audio signal.
In electronic music convolution is the imposition of a spectral or rhythmic structure on a sound. Often this envelope or structure is taken from another sound. The convolution of two signals is the filtering of one through the other.
- deconvolv - convolution and deconvolution of WAV files. Supported signal processing functions: correlation, convolution, de-convolution, convolution with Hilbert transformation, de-convolution with Hilbert transformation.
- https://github.com/PaulBatchelor/convolute - Convolves two audio files quickly.
- The HISSTools Impulse Response Toolbox: Convolution for the Masses - this paper introduces the HISSTools project, and its first release, the HISSTools Impulse Response Toolbox (HIRT); a set of tools for solving problems relating to convolution and impulse responses (IRs). Primarily, the aims and de- sign criteria for the HISSTools project are discussed. The elements of the HIRT are then outlined, along with motivating factors for its development, underlying technologies, design considerations and potential applications.
- https://github.com/HISSTools/HISSTools_Impulse_Response_Toolbox - HISSTools first release is a set of tools for working with convolution and impulse responses in Max. This set of object addresses various tasks, including measuring impulse responses, spectral display from realtime data/ buffers, and buffer-based convolution, deconvolution and inversion.
- ExpoChirpToolbox - an impulse response (IR) measurement tool chain in Pure Data, available for Windows, OSX and Linux. It implements the Exponential Sine Sweep method which has been so succesfully advocated by Angelo Farina. The toolbox is in developement, and has functionality for the generation of test signals, recording test responses, IR editing and basic IR analysis. The edited IR can be applied as a convolution filter in the toolbox.
- BruteFIR - a software convolution engine, a program for applying long FIR filters to multi-channel digital audio, either offline or in realtime. Its basic operation is specified through a configuration file, and filters, attenuation and delay can be changed in runtime through a simple command line interface. The FIR filter algorithm used is an optimised frequency domain algorithm, partly implemented in hand-coded assembler, thus throughput is extremely high. In realtime, a standard computer can typically run more than 10 channels with more than 60000 filter taps each.
- IR - a no-latency/low-latency, realtime, high performance signal convolver especially for creating reverb effects. Supports impulse responses with 1, 2 or 4 channels, in any soundfile format supported by libsndfile. 
- x42 Zero Config Convolver - A preset-only IR Reverb/Convolver. No parameters, no file-loading, just presets. This convolution effect allows processing with variable buffersize, up to a the nominal block-size. It is intended for use with Ardour 6, a LV2 host that provides realtime-priority information to this plugin for efficient background processing.
- https://github.com/johnflynnjohnflynn/jLibrary - FFT, convolution and general Pure Data library. jTabConv: Convolve two tables by multiplication in the frequency domain using FFT. jTabLookup; Fill a table with values processed by cross-connected object(s).
- https://github.com/LCAV/pyroomacoustics - a software package aimed at the rapid development and testing of audio array processing algorithms. "Suppose, for example, you wanted to produce a radio crime drama, and it so happens that, according to the scriptwriter, the story line absolutely must culminate in a satanic mass that quickly degenerates into a violent shootout, all taking place right around the altar of the highly reverberant acoustic environment of Oxford's Christ Church cathedral. To ensure that it sounds authentic, you asked the Dean of Christ Church for permission to record the final scene inside the cathedral, but somehow he fails to be convinced of the artistic merit of your production, and declines to give you permission. But recorded in a conventional studio, the scene sounds flat. So what do you do?"
- https://github.com/andrepxx/audio-tools - Tools for audio work, especially for measuring impulse responses of audio equipment.
- https://github.com/HiFi-LoFi/KlangFalter - Convolution audio plugin (e.g. for usage as convolution reverb). macOS
- http://distrho.sourceforge.net/ports - lv2 port
- SpecMatch - can be used to adapt the sound produced by a Guitarix setting to another recorded sound. It can also be used independently of Guitarix (cf. specmatch --help). Then you will need another convolver like the LV2 Convolution Reverb to use the produced filter. You can also use just the Python modules (e.g. from specmatch import SmoothedIR).
- Jconvolver - a Convolution Engine for JACK, based on FFT convolution and using non-uniform partition sizes: small ones at the start of the IR and building up to the most efficient size further on. It can perform zero-delay processing with moderate CPU load. Jconvolver uses the convolution engine designed for Aella, a convolution application for reverberation processing (to be announced later). This distributes the calculation over up to five threads, one for each partition size, running at priorities just below the the one of JACK's processing thread. This engine is a separate library that will be documented as soon as I can find the time.
- https://github.com/brugal/gtrfx/tree/master/jconv - a Convolution Engine for JACK using FFT-based partitioned convolution with multiple partition sizes. It's a command line version of what will be the core of the Aella reverb processor, but without the special reverb feautures, preset management, reverb envelope editing etc. that Aella will have.
- https://github.com/greenm01/jcgui - A little host for jconvolver
- https://sourceforge.net/projects/conviction - Frontend to manage the jack convolution engine jconv.
- https://github.com/wardnijman/Hijack-Filter - a vst/au plug-in which recreates a (analog) filter response with the use of a recording of a filtered train of impulses. It is created with the use of the JUCE framework. The plug-in is already in a working state, but still under construction.
- http://x42-plugins.com/x42/x42-convolver - Simple zero-latency convolution processor. (Mono, Mono To Stereo and True Stereo(2 in, 2 out, 4chan IR file: L -> L, R -> R, L -> R, R -> L) modes are supported. The main use-case is cabinet-emulation and generic signal processing where latency matters
- zeroconvo.lv2 - Zero-Config Convolver
- https://github.com/polyeffects/polyconvo.lv2 - modified from zeroconvolv2 to allow patch file setting and gain control. It is a LV2 plugin to convolve audio signals.
- https://github.com/wardnijman/Hijack-Filter - a VST/AU plug-in which recreates a (analog) filter response with the use of a recording of a filtered train of impulses. It is created with the use of the JUCE framework. The plug-in is already in a working state, but still under construction.
- HybridReverb2 - a convolution-based reverberation effect which combines the superior sound quality of a convolution reverb with the tuning capability of a feedback delay network. The sound quality of a convolution reverb depends on the quality of the used room impulse responses. HybridReverb2 comes with a set of room impulse responses which were synthesized with tinyAVE, an auralization software which was developed at the Institute of Communication Acoustics, Ruhr-Universität Bochum (Borß and Martin, 2009; Borß, 2009a). These room impulse responses are designed for a speaker setup with two front and two rear speakers (Borß, 2009b). For a full surround sound effect, you will need two plugins, one plugin which uses a "front" preset for the front channels and a second plugin which uses the corresponding "rear" preset for the rear channels.
- https://github.com/jpcima/HybridReverb2-impulse-response-database - This is the large impulse response database for HybridReverb2, redistributed under a Creative Commons ShareAlike license.
- https://github.com/hzeller/folve - a FUSE filesystem that convolves audio files on-the-fly including gapless support. Need to have precision-filtered audio adapted for your speakers and room (or just for effects), but your audio system doesn't have plug-ins for Finite-Impulse-Response filters and just can read files ? Folve is for you!
- Voxengo Deconvolver - offers a very convenient environment in which to deconvolve large sets of recorded files for use with convolution plug-ins that support only a small subset of available bit-depths. Windows $.
- https://github.com/JWBverheesen/cabinet-simulator - an lv2 cabinet simulator
- keFIR - provides music producers and sound engineers with a zero-latency FIR filter effect designed to help them enhance their tracks and generate astonishing sounds. Windows VST.
- https://github.com/steveb/firce - Genenerates LV2 Impulse Response plugins from audio files
- OpenAir Library - Demo, download and share acoustic impulse responses for auralization
- Download free impulse responses - L96 – Medium Hall, T600 – Natural Hall
- https://github.com/zamaudio/impulses - A collection of impulse responses in 48kHz 24 bit
- https://github.com/uduk/uduk-convolution - Fast direct convolution of two audio sources
- truc is a multi-effect VST plug-in, with 4 banks of effects controlled by the movement of 2 pucks. The top puck controls the level of each effect bank, the bottom puck modulates any 4 of 13 parameters within the effect banks. This allows continuous morphing of the sound by moving the pucks to vary the impact of each effect bank. As well as manually controlling each puck (either by mouse or midi controller) you can lock the pucks together and/or set them to move automatically, either randomly or by a configurable LFO, all in sync with your project tempo. Windows VST.
- truc2 is a multi-effect plug-in with 4 different effect modules and two automated XY pads to modulate their levels and parameters. It is designed to add variation and movement, anywhere along the scale of subtle to overkill and is suitable for any material. The 4 effect modules are DIRT, GRAIN, RING and DELAY. The first XY pad modulates the volume/mix level of each module, whilst the second XY pad modulates any 4 of the 15 automatable parameters. Both XY pads can be moved manually and additionally automated with a variety of LFO shapes, speeds and depths. Windows VST.
- https://delamanchavst.wordpress.com/2013/10/24/kitchen-sync - Windows VST.
- https://delamanchavst.wordpress.com/2013/10/23/machin - Windows VST.
- SynthTrack - an effect plugin. Applied to audio tracks, this plug-in applies Filter ADSR and LFO effects to synths on flat chords or moving sound waves. With this effect you can create chopping effects to your favorite sounds. It's ideal for creating the typical rhythmic gated pad sounds. With the envelope controlled step sequencer it's even possible to turn your pad sound into a powerful arp-like sequence. This plugin synchronizes to the host sequencer / DAW tempo. Windows/Mac VST.
- http://maxproject.wixsite.com/maxproject/vsti - Windows/Mac VST.
- Disto:Fx Free (Dirty Sound Destructor) - a multi-fx with distortion/dynamic shaper/saturation/filter/ring modulator/phaser/EQ and Input-Output control units. macOS AU/VST, Win VST 32-bit/64-bit.
- Amplio 2.0 - (VST Effect) is a way to enhance boring and dull sound. It's three band Equalizer with adjustable bands and additional multiband effect modules. Plugin was originally designed to enhance drum patterns, but version 2 is powerfull enough to be used on any type of sound.
- Hysteresis - delay effect with stutter, lowpass filter and modulation effects thrown into the feedback signal path. Process anything from drums and percussion to synth lines and sound effects. On top of being able to create incredibly wild signal glitch mutations, it can also be used to generate classic delay effects.
- Fracture - features a buffer effect, a multimode filter, three LFOs and a delay. The order of the effects in the processing chain can also be reconfigured. This plugin is geared toward adding glitchy articulations and abstract textures to your projects. Use it on anything from drums and percussion to synth lines and sound effects. Fracture’s intuitive interface and diverse features make it simple to give your projects a unique technical edge.
- ExEf - Extreme Effect, is an extremely powerful and flexible Real Time effect engine running on a PC under LINUX. It is designed to work with guitars, microphones and other instruments. It can run both in X Window System and command line. It supports both recording an post-processing. For easy start, try some presets! Requirepments include PC - Pentium MMX or above (Alpha may work as well), Full duplex soundcard.
- guitarix is a virtual guitar amplifier for Linux running on Jack Audio Connection Kit. It is free as in speech and free as in beer. The available sourcecode allows to build it on other UNIX-like systems, too, namely for BSD and for MacOSX.
- https://github.com/brummer10/GxPlugins.lv2 - A set of extra lv2 plugins from the guitarix project.
- https://github.com/snappy46/GuitarixDroid - Android app to select Guitarix preset using your favourite wifi connected android device
- YouTube: GuitarixDroid
- Rakarrack is a richly featured multi-effects processor emulating a guitar effects pedalboard. Effects include compressor, expander, noise gate, graphic equalizer, parametric equalizer, exciter, shuffle, convolotron, valve, flanger, dual flange, chorus, musicaldelay, arpie, echo with reverse playback, musical delay, reverb, digital phaser, analogic phaser, synthfilter, varyband, ring, wah-wah, alien-wah, mutromojo, harmonizer, looper and four flexible distortion modules including sub-octave modulation and dirty octave up. Most of the effects engine is built from modules found in the excellent software synthesizer ZynAddSubFX. Presets and user interface are optimized for guitar, but Rakarrack processes signals in stereo while it does not apply internal band-limiting filtering, and thus is well suited to all musical instruments and vocals. Rakarrack is designed for Linux distributions with Jack Audio Connection Kit.
- GNUitar is guitar effects software that allows you to use your PC as guitar processor. It includes the following effects: wah-wah, sustain, distortion, reverberator, echo, delay, tremolo, vibrato, and chorus/flanger.
- CP-GFX is simply a Cross Platform Guitar Effect Processor. The aim of the project is to create an extensible and easy to use program which is easy to port to different platforms an operating systems. Currently in development are Linux x86 and Win32 builds.
- RedFX - FX Processor (for guitar mainly) Effects: Noise Filter, Compressor, Wah, Distortion, Tremolo, Phaser, Flanger-Vibrato, Pitch Shifter, Delay, Reverb, EQ.
- Ecamegapedal is real-time effects processor software with a graphical user interface for controlling the effect parameters. It is meant to be used as a virtual guitar-fx or studio effects box. In addition to real-time operation, it also supports reading from and writing to audio files. All audio object and effect plugin types provided by the Ecasound libraries are supported. This includes ALSA, JACK, OSS, aRts, over 20 file formats, over 30 effect types, LADSPA plugins, and multi-operator effect presets. The implementation is based on the Ecasound and Qt libraries.
- https://github.com/brugal/gtrfx - Guitar effects program with plug-in in support allowing you to play guitar through your computer. Includes custom plug-ins for distortion, gain, recording, piped audio input, pitch tuner, etc. Supports alsa, jack, lasdpa audio plug-ins, and jconv convolution engine for guitar cabinet simulation.
- rack - ncurses jack ladspa-rack
- https://github.com/forart/ayemux - a program that patches LADSPA audio plugins using Jack to create a real time audio fx system similar to Guitar Rig. Patches of plugins can be saved as racks. Each rack can have multiple states. The states and racks can be switch via a midi foot controller.
- ToneLib-GFX - a collection of guitar amps, speaker cabinets and effects implemented in software for use with your computer, Windows PC or MAC. The software comes as a Standalone Application and as plug-ins for use with the most popular DAW (digital audio workstation) recording software. The Tonelib-GFX also supports 3rd party impulse responses (IRs), offering even greater tonal flexibility.
- https://github.com/andrepxx/go-dsp-guitar - implements a cross-platform multichannel multi-effects processor for electric guitars and other instruments, based upon concepts and algorithms originating from the field of circuit simulation. The software takes the signals from N audio input channels, processes them and provides N + 3 audio output channels. The user may, for example, connect the signal from individual instruments to separate input channels of his / her sound card / audio interface. The input signals are then taken and put through dedicated signal chains for processing. The software provides one dedicated signal chain for each input. The output from the last processing element in each chain is then sent to one of the output channels, providing one output channel for each of the input channels. The remaining three output channels include a dedicated metronome, which creates a monophonic click track, as well as a pair of "master output" channels providing a stereo mixdown of all processed signals, say for monitoring purposes.To manipulate the signal, the user may choose from a variety of highly customizable signal processing units, including the following.
- TAP-plugins is short for Tom's Audio Processing plugins. It is a bunch of LADSPA plugins for digital audio processing, intended for use in a professional DAW environment such as Ardour. These plugins should compile and run on any recent (that is, not seriously outdated) GNU/Linux system. They don't require any special libraries besides the standard GNU C and math libraries, which are expected to be provided on the machine used for compiling.
- https://github.com/moddevices/tap-lv2 - LV2 port for the TAP (Tom's Audio Processing) plugins
- CAPS is a collection of audio plugins comprising basic virtual guitar amplification and a small range of classic effects, signal processors and generators of mostly elementary and occasionally exotic nature. LADSPA.
- LSP (Linux Studio Plugins) is a collection of open-source plugins currently compatible with LADSPA and LV2 formats. Phase Detector, Delay Compensator Mono, Delay Compensator Stereo, Delay Compensator X2 Stereo.
- Infamous Plugins is a collection of open-source LV2 plugins. It hopefully helps fill some holes, supplying non-existing plugins for linux audio. There is little interest in creating ANOTHER compressor, or ANOTHER EQ when myriad other excellent lv2 versions of such already exist. At least until I become interested in making one of those things and feel I can do something different...
- ArtyFX - a plugin bundle of artistic real-time audio effects. The aim of this plugin collection is to allow the designing of your sound just as you desired using a fast, efficient workflow.
- Calf Studio Gear - available exclusively for LINUX-based operating systems and runs as a stand-alone effect rack connectable through Jack sound server or as plug-ins in every audio host that is able to fire up LV2 compilant devices, e.g. the highly recommended Ardour Audio Workstation. Play your SF2 sample banks, create filthy organs, fatten your sounds with phasers, delays, reverbs and other FX, process your recordings with gates, compressors, deesser and finally master your stuff with multiband dynamics - for free!
- mda-vst - Windows VST, including Bandisto - Multi-band distortion. BeatBox - Drum replacer, Combo - Amp & speaker simulator, De-ess - High frequency dynamics processor, Degrade - Sample quality reduction, Delay - Simple stereo delay with feedback tone control, Detune - Simple up/down pitch shifting thickener, Dither - Range of dither types including noise shaping, DubDelay - Delay with feedback saturation and time/pitch modulation, Dynamics - Compressor / Limiter / Gate, Envelope - Envelope follower / VCA, Image - Stereo image adjustment and M-S matrix, Leslie - Rotary speaker simulator, Limiter - Opto-electronic style, limiter, Loudness - Equal loudness contours for bass EQ and mix correction , Multiband - Multi-band compressor with M-S processing modes, Overdrive - Soft distortion, Re-Psycho! - Drum loop pitch changer, RezFilter - Resonant filter with LFO and envelope follower, Round Panner - 3D panner, Shepard - Continuously rising/falling tone generator, Splitter - Frequency / level crossover for setting up dynamic processing, Stereo Simulator - Haas delay and comb filtering, Sub-Bass Synthesizer - Several low frequency enhancement methods, Talkbox - High resolution vocoder, TestTone - Signal generator with pink and white noise, impulses and sweeps, Thru-Zero Flanger - Classic tape-flanging simulation, Tracker - Pitch tracking oscillator, or pitch tracking EQ, Vocoder - Switchable 8 or 16 band vocoder, VocInput - Pitch tracking oscillator for generating vocoder carrier input
- MDA-LV2 is an LV2 port of the MDA plugins by Paul Kellett. It contains 36 high-quality plugins for a variety of tasks. This is a more or less faithful port of both the effects and instrument plugins. The only functional difference in code is to support LV2-style toggle ports (> 0.0 is on, rather than 0.5). All the plugins have been tested, and thanks to several bug fixes this collection should be more reliable than the original.
- Steve Harris' LADSPA Plugins
- SAFE Plug-ins (SAFE stands for Semantic Audio Feature Extraction) are a series of DAW plug-ins that allow the user to provide timbral descriptions of the audio they are processing. The plug-in then analyses the audio and saves the anonymous data to our server. This data is collected from all users and analysed to give a general synopsis of the types of sound that a given descriptor is used for. All this information can then be used to create a series of ‘semantic plug-in settings’. Users will be able to load plug-in settings by typing in descriptive words regarding the timbre of the sound being processed. The more people who upload descriptors to the server the more perceptually representative the downloaded plug-in settings will get.
- https://github.com/falkTX/zam-plugins - Collection of LV2/LADSPA/VST/JACK audio plugins for high quality processing.
- x42-plugins - professional audio processing units available as LV2-plugins and JACK-applications
- DISTRHO Mini Series - This collection currently includes: 3-Band EQ, 3-Band Splitter, Ping Pong Pan
- Flo's Audio Plugins - completely free and open source (GPLv3), cross-platform (Windows and Linux, MacOS soon) by being available as VST (and maybe soon as LV2 and AudioUnit). So far, the plugins are somewhat guitar-related, but other tools might come in the future.
- https://github.com/danilobellini/hexd-plugins-lv2 - distortion, gain, highpass, lowpass
- https://github.com/remaincalm/dpfports - remaincalm effects suite ported to DPF environment
- Russolo Suite - a collection of LV2 plugins (and in the future, hopefully, VST) developed by Valerio Orlandini and named after the Futurist musician Luigi Russolo. For the moment, the attention is focused on the first part of this project: a sufficiently crazy synthesizer, called (what a surprise) Crazynth, and a do-it-all effect, called Omnifono.
- https://github.com/Anchakor/Ankh-Plugins - Audio plugins for use with LV2 supporting hosts. Currently consists of distortion, 3-band distortion, 4-band compressor plugins.
- https://github.com/linuxmao-org/njl-lv2 - NJL plugins by Nick Lamb ported to the LV2 specification by James Morris
- https://github.com/olegkapitonov/Kapitonov-Plugins-Pack - Set of plugins for guitar sound processing. LV2 and LADSPA.
- https://github.com/klem23/noise_factory - LV2 audio plugins for digital music on linux
- https://github.com/pjotrompet/Freaked - So far this contains- A pre-delay which can be very long and blurry- A Reverb Tail, can be very long. Together these two makes a nice Reverb- A Distortion, based on Filter techniques. a awesome real-time granulator programmed by Mayank Sanganeria.
- Computer Music Toolkit (CMT) is a collection of LADSPA plugins for use with software synthesis and recording packages on Linux. See the license before use.
- https://github.com/kronihias/mcfx - a suite of multichannel vst plug-ins or standalone applications (standalone currently meter and convolver only)
- https://github.com/linuxmao-org/shiru-plugins - A set of music plugins created by Shiru, unofficial DPF ports
- ELE - the Excellent Low-latency Effects
- ExEf - Extreme Effect, is an extremely powerful and flexible Real Time effect engine running on a PC under LINUX. It is designed to work with guitars, microphones and other instruments. It can run both in X Window System and command line.
- https://github.com/laudrup/Creox4 - a real-time sound processor. You can plug your electric guitar or any other musical instrument directly to the PC's sound card and start experimenting with various sound effects. Creox has a nice user-friendly GUI, a preset support, a low-latency DSP engine and each effect parameter can be altered "on the fly".
- Louderbox - a complete 8 band audio processor. Louderbox is intended to be used with software stereo and R[B]DS generators (but perfectly usable for other things (such as web "radio") using the jack audio connection kit under Linux (and possibly other systems but this is untested). LADSPA.
- Mustajuuri - an audio signal processing application and toolkit. It is designed to meet wide range of needs. The first and foremost is real-time effects processing. Mustajuuri can process guitar, vocals or any instrument with ease. It is also useful if you have a virtual reality system with more than 10 loudspeakers and you wonder how to control them all :-)
- BetabugsAudio (archived) - here you will find the plug-ins that we have available for download. These will have download buttons beneath them. Any GUIs without a download button are currently in development and not presently available. All other completed GUIs that are currently in need of a caring and affectionate programmer are available for viewing on the "job ads" page.
- https://github.com/guysherman/si-plugins - distortion, hi/low filters
- https://github.com/jdsierral/Spaco - a AU, VST and VST3 plugin suite related to spatialization.
- ScorchCrafter Guitar FX DAW Plug-ins - A group of audio DAW plug-ins targeting Windows (VST), Mac (VST/AU), and Linux, mostly for Guitar Amplifier simulation, with the C-120 being the flagship product (which started off long ago as a closed-source VST). Open source, mostly under GPL.
Windows VST / macOS AU
- GVST - several free VST effects and instruments for Windows. For the main part they are designed to be simple, light-weight and efficient, although some are more ambitious and some more experimental. Effects; GBand - Band-pass filter. GChorus - Chorus effect. GClip - Wave-shaping signal clipper. GComp - Compressor. GComp2 - Compressor. GDelay - Delay effect. GDuckDly - Ducking delay effect. GFader - Signal gain (-100 to 0 dB). GGain - Signal gain (-12 to 12 dB). GGate - Gate. GGrain - Granular resynthesis. GHi - High-pass filter. GLow - Low-pass filter. GLFO - Triple LFO effect. GMax - Limiter. GMonoBass - Bass stereo imaging effect. GMulti - Multi-band compressor and stereo enhancer. GNormal - Noise generator for avoiding denormal problems. GRevDly - Reverse delay effect. GSnap - Pitch-correction. GTune - Chromatic tuner.
- ReaPlugs VST FX Suite - Want to use some of the comprehensive FX plug-ins that REAPER provides, but stuck in another host? Haven't made the switch yet? Fear not -- you can download ReaPlugs, a package of FX that includes many of the plug-ins that come with REAPER, for free!
- Anarchy Rhythms - a hybrid between an effect and a drum machine. It takes an audio input and applies a user-controlled matrix of amplitude modulation, bandpass filtering, feedback loops, internal oscillation and compression. It allows you to compose rhythmic patterns from the sonic timbre of the input.
Anarchy Effects is a cross-platform bundle consisting of 5 audio plugins, each of which does a different novel form of frequency domain processing. VST versions now comply to VST 2.4 standard and plugins in different formats are available for both Mac and PC. Features: Parameter automation using MIDI controllers or VST automation. Complies with VST 2.4 standard. 32-bit & 64-bit versions for Mac (VST/AU) & PC (VST).
- SpectralAutopan – assigns different pan positions to the different component pitches in the input signal. The effect pitch has on pan position is controlled by control points, which can change in pan position and pitch according to LFOs. This adds stereo depth and motion to sounds.
- Corkscrew – mixes together multiple pitch-shifts of the input signal, increasing or decreasing their pitches in parallel, and fading them in/out at the extremes of their range. This creates the illusion of a sound that seems to continually rise or fall, but doesn’t actually change in average pitch.
- HarmonicAdder – creates harmonic resonances by pitch shifting the dominant frequencies in your input signal by the various intervals in the harmonic series (octave, octave+fifth, two octaves, two octaves+major third etc). These harmonics can be mixed with the dry input signal to make it more resonant, or used on their own as a new sound.
- LengthSeparator – bisects the input signal according to the lengths of its component frequencies. Short sounds become the ‘transient’ part, long sounds become the ‘stable’ part. These parts can be isolated (ie the other part removed), or assigned different pan positions to create stereo movement.
- Convoluter – applies a convolution matrix to the spectral representation of the input signal. This bends the sound along the continuum between pure sine tones and pure noise.
- GeoSynth - a vst instrument made several years ago, but never released – I wasn’t as excited as I’d hoped about the sounds it made. But it’s here now so you can judge for yourself. There’s no doubting that it’s a great idea, whether the sounds light your candle or not.
- SwarmSynth - a vst instrument which uses a flocking algorithm to control a bank of oscillators as they move through an envelope-constrained 5 dimensional parametric hyperspace.
- Svep Phaser - Flanger - Chorus (VST + AU + AAX) - Svep is a stereo modulation filter effect suitable for any sound. All parameters are easily editable in one screen and the clean and responsive user interface encourages creativity. Tweak it to produce anything from old-school phasers to subtle choruses.
- SyndtSphere - VST + AU. basically a sphere version of the polyphonic synthesizer Syndt. With a minimalistic approach, it features a unique experience of ”surfing” between presets. All parameters are morphed according to the proximity of the different presets. By rotating a sphere that consists of more than 70 professionally created states, anyone can dial in the perfect sound without having to deal with specific parameters. In addition to the sphere, a ping-pong delay and a few more global settings are available.
- http://destroyfx.smartelectronix.com/ - windows/mac
- http://www.smartelectronix.com/index.php?selected=home - many devs, mostly Windows VST
- https://github.com/IBEngineering/ModularEffectBox - box of modular effects for guitar (teensy)
- http://www.rs-met.com/freebies.html - Windows VST
- Tweakbench - free VST instruments and free VST effects
- http://www.contralogic.com/vst-plugins/ - Windows VST