Home Plugins Get it!

Free Your Sound!

Freedom by Bohrmann flickr.com You have the need for professional and state-of-the-art audio plug-ins - but don't have thousands of bucks to spend on it?

Then we believe you will love Calf studio gear!

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

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!

Calf Studio Gear...

Calf Icon 64x64 ...is 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


Visit Us @

Sourceforge Logo

...and get:
  • Bug report system
  • Feature requests and patch upload
  • Comments, votes and reviews
  • All released tarballs from Calf and
  • A complete version history

Audio Demos

Calf In The Field

Mioslave logo proudly produces exclusively with Calf audio plug-ins. Get some tracks (free CC license) on their website and have a listen to this package used in the field.


CALF Wallpapers Get a CALF studio gear wallpaper sized to fit your screen. Click on the thumbnail to see a preview and choose your resolution in the list below.


Calf is partially released under LGPL
(GNU Lesser General Public License)

The calfjackhost (Calf rack) is released under GPL
(GNU General Public License)
due to licensing restrictions of external code.

You are free to use, copy, share and modify this software.

GPL and LGPL are published by the

Free Software Foundation Logo

Calf is brought to you by...

Krzysztof Foltman

Krzysztof Foltman - The Head of the Pack

A versatile cross-platform programmer and senior software engineer, Krzysztof is interested in various technologies from Python and Linux to C++ and Win32. He also is a jazz/electronic musician wannabe and software musical instrument creator in his spare time. Krzysztof initiated the project in 2007 and is the main developer of the Calf codebase. He implemented most of the DSP routines and all delay effects as well as the framework Calf is based on. Moreover he designed the synthesizers of the Calf suite. Additionally he maintains the Git-repository and keeps an eye on code quality and effectiveness.

Markus Schmidt

Markus Schmidt - Studio Plugins and Design

A german designer, producer, musician and programmer, Markus joined the team in 2009 and signs responsible for the design of every visual aspect of Calf. Annoyed by the lack of high quality open source sound processing plug-ins he has supplied the Calf suite with limiting processors, enhanced dynamics modules, equalizers, the Analyzer, some modulation effects, lots of tools and different saturation effects. His other projects include traGtor - a GTK-UI for FFmpeg under GNU Linux, xplanetFX - HQ renderings of mother earth as a wallpaper and JAMMIN*INC - a pure CreativeCommons band.

Christian Holschuh

Christian Holschuh - Limiter, Analyzer, Transient Designer

A competent mathematician and physicist, Christian is one of the core developers of the lookahead limiter routine, the multiband limiter solution, the FFT Analyzer and the Transient Designer. As a member of JAMMIN*INC he directly profits from a professional audio processing suite under Linux and was highly motivated to pull one all-nighter after the other to create a musically sounding loudness maximizer.

Thor Harald Johansen

Thor Harald Johansen - Dynamics Foundation

A professional programmer from Norway, Thor is responsible for the development of the dynamics routine all the Calf plugins are based upon. After a lot of discussion and intense brainstorming with Krzysztof he built one of the best and most flexible level detection and gain reduction modules for audio production. His routine drives all compressors and the deesser and supplies the foundation for the expander plugins.

Damien Zammit

Damien Zammit - Gate routine and different plug-ins

Applying his mathematics skills to problems in biology, Damien also finds time to contribute new audio processing plugins to the open source community. Having released the Zam suite of audio plugins he has also made valuable contributions to Calf such as the Mono Compressor, Phono EQ and added the basal gate routine to the package.

Tom Szilagyi

Tom Szilagyi - Distortion Routine

While taking refuge from corporate IT consulting, Tom developed the TAP-plugin pack available for Linux audio workstations as well as Aqualung, a feature-rich cross-platform music player. His distortion routine taken from TAP Tubewarmth is the base for the saturation effects, namely Saturator, Exciter and Bass Enhancer. He kindly contributed his code to the Calf team, thus improving quality and functionality of the package a lot.

Hans Baier

Hans Baier - Filterclavier and Line Graph Improvements

Making a living as a crossplatform developer in Java and Python, free EDP trainer and author about Linux and UNIX, Hans once contributed the Filterclavier to the Calf plug-in suite. In late 2012 he re-entered the team with some improvements to the line graph displays. Read more about Hans @ hans-baier.de.

Further contributions:

Juuso Alasuutari

Implementation of LASH 0.6 support

Torben Hohn

Optimization of rendering code

Thorsten Wilms

Design of the formerly used little cow icon

SourceForge.net Logo