Calf studio gear is designed to give you a professional production environment for your open source operating system. It's focused on high-quality sound processing and a highly usable interface.

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.

Calf Multi Chorus

Multi-tap stereo chorus with adjustable number of voices. Adds warmth and richness, especially if you give it a lot of CPU power. A lot of options make this effect highly flexible in expression.

Development: Krzysztof Foltman

Calf Phaser

A pretty basic stereo phaser with all typical settings (center frequency, modulation depth, LFO rate number of stages, feedback, amount, L-R LFO phase difference and amount). Provides a LFO reset button for consistent song playback. The number of stages goes up to 12.

Development: Krzysztof Foltman

Calf Flanger

Simple stereo flanger with linear interpolation. If "zipper noise" of basic flanger effects is driving you mad, try this one!

Development: Krzysztof Foltman

Calf Rotary Speaker

Work in progress (read: still sounds rather boring). Can morph between slow and fast mode when switched using MIDI, control ports or automation.

Development: Krzysztof Foltman

Calf Pulsator

Calf Pulsator is something inbetween an autopanner and a tremolo, but it can produce funny stereo effects as well. Pulsator changes the volume of the left and right channel based on a LFO (low frequency oscillator) with different waveforms and shifted phases.

Development: Markus Schmidt

Calf Ring Modulator

Calf Ring Modulator extends the typical ring modulation by two LFO which are able to modulate different aspects of the modulation to produce crazy effects.

Development: Markus Schmidt

Calf Reverb

Simple reverb with basic controls and relatively neutral sound. No dreaded metal barrel sound, but at the expense of higher CPU use and less time density. Like most artificial reverberators, it is not suitable for every instrument, but try it on vocals, guitars or Calf synths, and you will like it.

Development: Krzysztof Foltman

Calf Vintage Delay

A very simple simulation of tape echo, with a filter in a feedback loop and BPM-based time setting. The number of controls is limited, but all the essential stuff is there. Suitable for synths, guitars and almost anything else.

Development: Krzysztof Foltman

Calf Compensation Delay Line

Compensation Delay Line is a metric based delay to compensate differing positions of microphones or speakers.

Development: Vladimir Sadovnikov

Calf Reverse Delay

The Reverse Delay reverses the input signal while feeding the delay buffer resulting in a reversed sound effect.

Development: Drgreenthumb

Calf Compressor

Smooth sounding dynamic compressor with a variety of settings, written by Thor Harald Johansen. RMS/peak modes, A-weighting, metering - feels like real studio gear!

Development: Thor Harald Johansen, Krzysztof Foltman

Calf Sidechain Compressor

Based on Thor's compression routine, the Calf Sidechain Compressor is the universal tool for any problem concerning sound dynamics. A highly flexible filter stage in the sidechain lets you eliminate dynamic rumbling, clipping sibilants and similar disturbances. The sidechain offers split modes, too.

Development: Markus Schmidt, Thor Harald Johansen

Calf Multiband Compressor

The first multiband compressor with real plugin capabilities on linux audio worksations - four channels with separate compression stages will blow up the loudness of your tracks. This one is also based upon Thor's compression routine.

Development: Markus Schmidt, Thor Harald Johansen

Calf Mono Compressor

Single banded compressor based on a different compression routine than the main Calf Compressor.

Development: Damien Zammit

Calf Deesser

Due to it's flexibility in sound and options Thor's compressor constitutes the core of Calf Deesser. An optimized filter stage in the sidechain gives you great control over dynamic highs. This deesser offers a split mode for special purposes.

Development: Markus Schmidt, Thor Harald Johansen

Calf Gate

Because of the flexibility of Thor's compression detection we were able to use it as a solid base for a noise gate. The controls may seem a bit unusual but they provide high flexibility in detecting and eleminating your noise floor - Calf Gate bites off your sustain!

Development: Damien Zammit, Thor Harald Johansson

Calf Sidechain Gate

The same flexible sidechain filter stage that is used in the Calf Sidechain Compressor turns Calf Gate into a very precise gating plugin. Especially in drum recordings Calf Sidechain Gate offers complete control over the audibility of your drums. You want to cut away the complete lower end of a playback leaving the bassdrum where it is - a split mode makes it happen.

Development: Markus Schmidt, Damien Zammit, Thor Harald Johansson

Calf Multiband Gate

Four channels with separate gate stages provide enough flexibility to clean up really problematic material like a humming and noisy narrator. This one is also based on Damien Zammit's gate routine.

Development: Markus Schmidt, Damien Zammit, Thor Harald Johansson

Calf Limiter

The broadband Limiter included in the Calf suite uses lookahead technology to smoothen the gain reduction process while preventing your signals from rising above the selected threshold.

Development: Christian Holschuh, Markus Schmidt

Calf Multiband Limiter

The Multiband Limiter brings presence, punch and loudness to your mix. Combined with the Multiband Compressor Calf is a good choice for mastering your material to a professional level. The weighting of single bands prevents certain ranges of the signal from being cut off or pressed to the background.

Development: Markus Schmidt, Christian Holschuh

Calf Sidechain Limiter

The Sidechain Limiter is mainly acting like the Multiband Limiter but provides an additional stereo channel to feed material into which is supposed to always stay in front of your mix. This channel is limited and weighted in the same manner the frequency bands are treated.

Development: Markus Schmidt, Christian Holschuh

Calf Sidechain Limiter

The Sidechain Limiter is mainly acting like the Multiband Limiter but provides an additional stereo channel to feed material into which is supposed to always stay in front of your mix. This channel is limited and weighted in the same manner the frequency bands are treated.

Development: Markus Schmidt, Christian Holschuh

Calf Transient Designer

Transient Designer is used to modify the envelope of percussive signals (signals with a defined attack or transient) like drum sounds or percussion instruments. It is able to remove or to boost the attack or the release of a signal independent from its real gain in contrast to the operation of compressors or expanders. The Calf Transient Designer is able to add a defined sustain phase to the signal. A customizable filter for the envelope narrows the frequency range triggering the Transient Designer.

Development: Christian Holschuh, Markus Schmidt

Calf Filter

Selectable 12dB/24dB/36dB rolloff, lowpass or highpass with inertia/smoothing for cutoff for more "analog" sound when tweaking. Particularly useful for drum loops or guitars in house music.

Development: Krzysztof Foltman

Calf Filterclavier

This filter is controllable via MIDI and follows the received Note-On signals with its frequency settings.

Development: Hans Baier [

Calf Envelope Filter

This plug-in is also known as Auto-Wah - a filter following the envelope of a signal. The Calf version provides a couple of filters to choose from together with some fine grained settings of the envelope to frequency calculation like setting a curve from convex over linear to concave. Additionally there's a sidechain input to use a different signal for the envelope than for the processing itself.

Development: Markus Schmidt

Calf Emphasis

This device adds or substracts different frequency response curves in order to create standard compliant material for different media like emphased CD or vinyl records.

Development: Damien Zammit

Calf Vocoder

Modulates the frequency response of a carrier signal by measuring the response of a modulator signal in realtime. In other words, let your guitar speak. Lots of settings like the amount or quality of bands will give complete control over sound and CPU load.

Development: Markus Schmidt, Christian Holschuh

Calf 5-Band Equalizer

Based on different filters these series of equalizers was invented to provide some specialized tools for everyday's signal processing. A gain of +-36dB and maximum slew rates for the peak filters offer great flexibility for eliminating or creating resonances and shaping your frequency range. All bands are capable of processing stereo, left, right, M-S mid or M-S side individually. An Analyzer in the display provides a visual representation of your settings. This version offers two shelving filters and 3 peak filters. It's the right choice for some minor frequency range adjustments.

Development: Markus Schmidt, Krzysztof Foltman

Calf 8-Band Equalizer

Based on different filters these series of equalizers was invented to provide some specialized tools for everyday's signal processing. A gain of +-36dB and maximum slew rates for the peak filters offer great flexibility for eliminating or creating resonances and shaping your frequency range. All bands are capable of processing stereo, left, right, M-S mid or M-S side individually. An Analyzer in the display provides a visual representation of your settings. This version offers a low and a high pass, two shelving filters and 4 peak filters and is the perfect replacement of a channel strip EQ.

Development: Markus Schmidt, Krzysztof Foltman

Calf 12-Band Equalizer

Based on different filters these series of equalizers was invented to provide some specialized tools for everyday's signal processing. A gain of +-36dB and maximum slew rates for the peak filters offer great flexibility for eliminating or creating resonances and shaping your frequency range. All bands are capable of processing stereo, left, right, M-S mid or M-S side individually. An Analyzer in the display provides a visual representation of your settings. This version offers a low and a high pass, two shelving filters and 8 peak filters and is designed to handle the real problems.

Development: Markus Schmidt, Krzysztof Foltman

Calf 30-Band Equalizer

This graphical equalizer is able to use different filters for the manipulation of your material.

Development: Drgreenthumb

Calf Saturator

Universal distortion tool. Saturator can act as a guitar distortion as well as a harmonics generator. Some useful filters before and after the distortion stage and gapless adjustment between 2nd and 3rd harmonics give you a great flexibility in sound. The saturation stage is taken from Tom Szilakyi's TAP-plugin pack.

Development: Tom Szilagyi, Markus Schmidt

Calf Exciter

Filtered distortion to add brilliance to your tracks. The saturation stage is taken from Tom Szilakyi's TAP-plugin pack.

Development: Markus Schmidt, Tom Szilagyi

Calf Bass Enhancer

Harmonics for fattening the lower end. The saturation stage is taken from Tom Szilakyi's TAP-plugin pack.

Development: Markus Schmidt, Tom Szilagyi

Calf Tape Simulator

Calf Tape Simulator modifies signals as if they were recorded on a tape machine or tape deck. It is able to simulate different aspects of magnetical recordings like loss of brilliance, noise, softer transients, distortion/compression of the signal and mechanical tape threading path problems.

Development: Markus Schmidt, Christian Holschuh

Calf Vinyl

Calf Vinyl offers six sound generators (Motor, Static, Noise, Rumble, Crackle, Crinkle) with individual pitch and gain, droning (controlled by rpm) and heavy filtering up to ancient gramophone sounds.

Development: Markus Schmidt

Calf Crusher

The Calf Crusher lets you crush your signal by reducing the bit resolution. The reduction can be done in a linear or logarithmic way while the logarithmic way results in a much smoother sound in low volume signals. On top of that, the edges, which are created by the bit reduction, can be anti-aliased. This lets you create a numerous variety of sound effects for your signal.

Development: Markus Schmidt, Christian Holschuh

Calf Mono Input

Since Calf doesn't provide mono versions of the plugins yet, it is essential to split your signal into stereo signals when used in an audio production environment like Ardour. The Mono Input has some useful functions to deal with the split process like phase inversion and balance.

Development: Markus Schmidt

Calf Stereo Tools

This device is a toolbox for handling stereo signals. It is able to change M/S microphone signals to L/R and vice versa. Switching the phase, muting a channel, widening the stereo base or delaying one of the channels up to 20ms are some of the features of this input or mastering tool.

Development: Markus Schmidt

Calf Haas Stereo Enhancer

The Haas Stereo Enhancer widens your stereo material via a simple delay line.

Development: Vladimir Sadovnikov

Calf Multi Spread

Calf Multi Spread spreads your mono signal into stereo without any additional delay line – just by distributing the frequency spectrum equally between left and right. Choose the amount of filters per band and the direction of the distribution.

Development: Markus Schmidt

Calf Multiband Enhancer

Multiband stereo base and additional harmonics for widening your stereo image on four different frequency ranges.

Development: Markus Schmidt

Calf X-Over 2 Band

The X-Over series in Calf provides a comfortable and flexible way to split a signal in different frequency bands for feeding dedicated speaker setups or building your own multiband effects setups. This device separates the signal into two different frequency bands.

Development: Markus Schmidt

Calf X-Over 3 Band

The X-Over series in Calf provides a comfortable and flexible way to split a signal in different frequency bands for feeding dedicated speaker setups or building your own multiband effects setups. This device separates the signal into three different frequency bands.

Development: Markus Schmidt

Calf X-Over 4 Band

The X-Over series in Calf provides a comfortable and flexible way to split a signal in different frequency bands for feeding dedicated speaker setups or building your own multiband effects setups. This device separates the signal into four different frequency bands.

Development: Markus Schmidt