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bkFX - BlauKraut Effects suite
==============================

(c) 2012-2026 Dominique Wurtz

bkFX is a collection of audio effects for Windows and Linux platforms. The included effects range from engineering/utility processors to rather sophisticated multi-effect units. Features have been carefully designed to combine versatility with easy usability. bkFX is FREEWARE, see license terms below.

Key features:
* very low CPU usage
* parameter smoothing where it makes sense
* fully samplerate agnostic (above 44.1 kHz)
* supported platforms: Windows CLAP/VST3 32-/64-bit, Linux CLAP/VST3 64-bit

REMARK: Most effects in bkFX deliberately operate without internal oversampling for the reasons stated here:
http://varietyofsound.wordpress.com/2012/11/02/working-itb-at-higher-sampling-rates/
Depending on the type of effect, input signal characteristics and settings, digital aliasing or frequency response warping artifacts can occur. In this case, increasing the project samplerate is recommended. In all but the most extreme cases, working at 88.2kHz or 96kHz should yield excellent audio quality with acceptable CPU usage. For the final rendering of a project, an even higher samplerate might be advantaguous.

Version History
===============

0.10.0 Beta (2026-01-06)
* bkReverb: Add new core algorithm ("Type II"). Compared to the existing one, it features a slightly
  quicker echo density build-up and allows for a slower attack.
* bkReverb: Revamp high frequency damping parameter to achieve more consistent interaction with RT60
  and size parameters. Caveat: breaking change, sound of the reverb tail may noticably differ from previous
  plugin versions with "extreme" settings (i.e. small size, short decay, high damping). With
  typical settings, though, the difference should be subtle enough to not bother.
* bkLimiter: New Brickwall peak limiter optimized for transparency (i.e. low distortion and volume
  fluctuations) and ease of use
* bkComp: Minor algorithm improvements and fixes
* bkErosion: Add wide sine signal source

0.9.2 Beta (2025-10-03)
* FIX: Switch/list parameters were hidden in some popular DAWs (e.g. Ardour, Bitwig),
  rendering the plug-ins basically unusable! The fix was to report all parameters as automatable.
  Remark: I think the behavior of those applications is wrong in this regard. Most of those
  parameters are in fact not well suited for automation, so this is more of a work-around.
* bkFreqSplitter: Reduce CPU load of 4th order crossover filters
* VST3: Properly report discrete parameters to host

0.9.1 Beta (2025-04-21)
* bkComp: Report gain reduction metering to hosts that support it (e.g. Studio One, Reaper)
* bkFreqSplitter: Add 4th order crossover filters (24 db/oct)
* bkDelay: Reduce tape noise level
* Linux: Fix compatibility with glibc 2.41

0.9.0 Beta (2024-10-22)
* bkChorus: Add new Wobble mode which uses a sine LFO instad of triangle LFO.
* bkChorus: Revised Chorus+ mode. Should in general sound lusher with less flanging and periodic beating
* bkChorus: Add switch to phase invert wet signal which alters overall tone.
* bkComp: Replace Look-Ahead function by Peak Limiter
* bkComp: Various algorithm improvements
* bkDelay: Add Tape emulation mode
* bkDelay: Better balanced stereo field in ping pong mode
* bkDelay: More convenient Feedback parameter mapping
* bkReverb: Add pre-delay parameter
* bkReverb: Minor tweaks
* BUGFIX: VST3 compatibility issues

0.8.0 Beta (2023-01-29)
* NEW bkComp: a simple yet effective downward/upward compressor
* bkChorus: fix LFO phase when switching from Chorus+ to Chorus mode

0.7.2 Beta (2022-08-06)
* CLAP: fix potential crash
* CLAP: allow editing value by text input (if host supports this)

0.7.1 Beta (2022-07-13)
* Fix CLAP compatibility
* Linux: fix compatibility with major distros (e.g. Debian Stable, Ubuntu 20.04)
* CLAP: enable parameter modulation

0.7.0 Beta (2022-06-19)
* Add CLAP support (see cleveraudio.org)

0.6.1 Beta (2021-06-09)
* Fix Linux VST3 compatibility with Ardour and possibly other hosts

0.6.0a Beta (2021-06-06)
* re-package Linux VST3 plug-ins in "bundle" directories which is required to have them detected by certain hosts such as Carla

0.6.0 Beta (2021-06-05)
* NEW bkReverb: high-quality algorithmic reverberator. Equally suited for small acoustic ambiences and huge spaces.
* NEW bkDualFilter (replaces bkModFilter): two multi-mode filters that can be routed in serial or parallel
    Available filter modes: 4-pole ladder Lowpass, Highpass, Bandpass, 2-pole Sallen-Key LP, HP, BP, 2-pole Notch, 4-pole Allpass with positive or negative feedback, Comb filter with positive or negative feedback
* NEW bkChorus (replaces bkEnsemble): 
    Available modes:
    Chorus: classic two-voice chorus
    Chorus+: four-voice chorus
    Ensemble: chorus effect from classic string synths (taken over from bkEnsemble)
    Dimension: popular modern stereo expansion effect
    Dimension+: popular modern stereo expansion effect
* NEW bkErosion: a popular degrading effect. Besides the classic effect, can alternatively operate as a ring modulator.
* Switch to VST3 64-bit (VST2 dropped)
* bkClipper: add sinusoid fold-back waveshaping
* bkClipper: reduce aliasing

0.5.1 Beta (2014-11-26)
* new Linux 64-bit builds
* FIX: crashes with 32-bit versions

0.5 Beta (2013-08-28)
* bkFreqSplitter: improved frequency response when using all 3 bands
* bkModFilter: revised LP4 filter
* bkModFilter: revised/fixed HP2/HP4 filters
* bkModFilter: new 2-pole Notch and 4-pole Bandpass filter modes

0.4 Beta (2013-06-16)

* bkChannelTool: reworked "Width" parameter (200% -> pure side channel)
* bkDelay: new "Input" parameter: allows to sum delay input to mono or invert input stereo channels.
* bkDelay: replace "Stereo Spread" parameter by "Width" parameter (works like in bkChannelTool)
* support parameter value text input (unfortunately only supported by few hosts, e.g. H. Seib's VSTHost)
* support Cockos REAPER extension for text input of automation break point value
* bkChannelTool, bkDelay, bkEnsemble: fix crash in x86 builds
* bkDelay, bkModFilter: fix another potential crasher
* bkEnsemble: slightly randomize LFO rate across instances
* ditch bkPassthrough again since bkChannelTool uses almost no CPU as well and can thus be used for the same purpose

0.3 Beta (2013-4-15)
* new plugin bkEnsemble: ensemble chorus
* new plugin bkPassthrough: passes through audio unchanged. Useful e.g. for REAPER channel routing.
* bkDelay, bkPitch, parts of bkChannelTool: rewrote DSP code using SSE, more efficient.
* bkDelay: 2nd-order smoothing for delay time to allow truly artifact-free automation
* bkChannelTool: extended "Width" parameter range to 200% (enhance stereo image)

0.2 Beta (2013-1-6)
* bkChannelTool: BUGFIX: pan was reversed
* bkDelay: revised delay time parameters (breaks projects, sorry!)
* bkDelay: make feedback parameter value range more nonlinear to allow easier adjustment close to 0 dB
* bkDelay: adhere to host tempo changes
* bkDelay: more presets
* bkPitch: window size parameter now affects signal *after* pitch shifting (thus independent of pitch).
* bkPitch: smooth automation of window size now possible
* misc. internal improvements
* reference manual update

0.1 Beta
* initial release

System requirements
===================

* Intel(R) x86-compatible CPU with support for Streaming SIMD Extensions 3 (SSE3)
* Microsoft(R) Windows(R) operating system (Vista or later) or Linux
* CLAP or VST3 compatible 64-bit host application
* Linux: GNU libc >= 2.31.0

Installation
============

Windows VST3:
Copy .vst3 files into your system's VSTPlugins folder (usually C:\Program Files\Common\VST3).

Windows CLAP:
Copy .clap files into your system's CLAP plugin folder (usually C:\Program Files\Common\CLAP).

Linux VST3:
Copy .vst3 directories into your VST directory (usually ~/.vst3).

Linux CLAP:
Copy .clap files into your CLAP plugin folder (usually ~/.clap).

Legal Disclaimer
================

Microsoft(R), Windows(R), and Windows VistaTM are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries. 
ASIO and VST are trademarks of Steinberg Media Technologies GmbH
Other company and product names are trademarks or registered trademarks of their respective owners

License
=======

See license.txt

For licensing information of used open-source software, see opensource.txt
