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This site is no longer maintained and will be closed in a few months.
A new one is available at www.kokkinizita.net/linuxaudio


Yet Another Scrolling Scope. Main features: up to 32 channels, variable scrolling speed, automatic gain control, and very light on CPU usage. Beta release.

HOA NF filters

A set of IIR filters combining forward and inverse Near Field correction for Higher Order Ambisonics, up to 4th order. A 'textbook' implementation of such filters will not work when using single precision floating point. There is a simple solution for this explained in this note which also comes with the sources.


Aliki (alpha version released) is an integrated system for Room Impulse Measurement. It uses the logarithmic sweep method developed by Angelo Farina (university of Parma, Italy). A prototype version was presented at the 4th Linux Audio Conference. Development of Aliki continues as time permits... As part of the Aliki workshop at the LAC, the program was used to measure the IR of the concert hall at ZKM, Karlsruhe. You can see some pictures of the workshop here.


JACE is a Convolution Engine for JACK and ALSA, using FFT-based partitioned convolution with uniform partition sizes. This is a first alpha release. Main features:

- Any matrix of convolutions between up to 16 input and 16 outputs.
- Maximum length for each convolution is one megasample (nearly 22 seconds at 48 kHz).
- Allows the use of a period size down to 1/16 of the partition size.
- It's fast.


Jaaa (JACK and ALSA Audio Analyser, is an audio signal generator and spectrum analyser designed to make accurate measurements.


Update solving possible hangup due to uninitialised memory.

Japa (JACK and ALSA Perceptual Analyser), is a 'perceptual' or 'psychoacoustic' audio spectrum analyser.
In contrast to JAAA, this is more an acoustical or musical tool than a purely technical one. Possible uses include spectrum monitoring while mixing or mastering, evaluation of ambient noise, and (using pink noise), equalisation of PA systems.

Some screenshots: with default color scheme and warped F-scale or with alternate color scheme and Log F-scale


This is a small command line JACK app you can use to measure the latency of your sound card. It uses a phase measurements on a set of tones to measure the delay from the output to the input. Accuracy is about 1/1000 of a sample.


A command line JACK app generating white and pink gaussian noise.


High precision A-weighting filter for sound measurements. IIR implementation working at 44.1, 48, 88.2 and 96 kHz. Accuracy should be in the order of 0.1 dB over most of the frequency range (errors occur only close to FS/2). The tarball contains: C++ class, JACK in-process client and LADSPA plugin.

Ladspa Plugins


Third release, improved decoders now using phase aligned shelf filters.

A set of ambisonics plugins, mainly to be used within Ardour. Mono and stereo to B-format panning, horizontal rotator, square, hexagon and cube decoders. More to follow.



This plugin contains four versions of a digital implementation of the voltage controlled lowpass filter designed by Robert A. Moog. Many software versions of this filter already exist. Most use some limiting mechanism in order to keep the self-oscillation amplitude under control, but as far as I know, none of them attempt to accurately emulate the non-linear circuit elements of the original analog filter. To do this has been the main reason for developing this plugin.


This is a highpass filter, again based on a classic design by Robert Moog. First release, and leaves some room for improvement.

phaser1 is similar to the CSound module 'phaser1'. It's a series connection of 1 to 30 first order allpass filters with feedback. The frequency of the allpass filter can be controlled by an external modulation signal. Phaser1+LFO is the same thing, but the external modulation has been replaced by a built-in LFO. The 'LFO waveform' control ranges from a falling saw wave, over triangle, to a rising saw wave.

These two plugins are based on a CSound orchestra file by Sean Costello. There are two low frequency oscillators, each having three outputs that are 120 degrees apart in phase. The summed outputs modulate three delay lines.
The two versions are functionally identical. The second one upsamples the input to the delay lines in an attempt to mitigate the errors produced by the linear interpolation at the output. If you hear any difference please let me know which one you prefer.


This is a stereo reverb plugin based on the well-known greverb.


This plugin contains three anti-aliased oscillators, all based on the concept of using precomputed bandlimited Dirac pulses to construct the classical waveforms. They are both memory and CPU efficient. The first one produces a flat spectrum (impulses) and the second generates a sawtooth waveform. The third one (new in 0.3.0), provides a variable width rectangular waveform.
This is unfinished work, and I will return to it some day...

Sean Bolton has written a great set of bandlimited VCOs based on the same principles (from Stilson & Smith and Brandt). They also feature hard sync but wil take a bit more CPU cycles. You can grab his blepvco plugins here


There's one plugin in this first release, a four-band parametric equaliser. Each section has an active/bypass switch, frequency, bandwidth and gain controls. There is also a global bypass switch and gain control.

The 2nd order resonant filters are implemented using a Mitra-Regalia style lattice filter, which has the nice property of being stable even while parameters are being changed.

All switches and controls are internally smoothed, so they can be used 'live' whithout any clicks or zipper noises. This should make this plugin a good candidate for use in systems that allow automation of plugin control ports, such as Ardour, or for stage use.


Most of these plugins were developed to be used as modules in the incredibly versatile AlsaModularSynth created by Matthias Nagorni. This is why the basic frequency control inputs are all logarithmic (1/octave). You can find AMS, example patches using the plugins and other nice things from Matthias via the link above.

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