Simple simulation of an electronic organ like e.g. Vox Continental. This is a toolbox for creating an electronic organ program with JACK MIDI input and JACK audio output for Linux.

Read the Changelog, the README and download the actual source and the latest debian builds from bitbucket or a debian sid package from my repository.

The Software

Connie is a JACK application. It has one MIDI input and a stereo audio output. The sound is generated by sampling lookup tables with calculated waves at 12 equal tempered frequencies for one octave. The upper octaves were generated by sampling with greater sample steps. This solution allows a moderate cpu load and makes the proggie eeepc-friendly.
The sound of each note is ramped on and off to reduce the key click. For each sounding note four stops are mixed:
The subharmonic 16' (one octave lower)
The unison stop 8'
The octave stop 4' (one octave higher)
The mixture stop 2 2/3' (octave+fifth), 2' (superoctave), 1 3/5' (superoct.+major third), 1' (superoct.+octave)

To cover a broad variation of sounds three voices from two lookup tables can be mixed:
Flute - a sine wave
Reed - a bandlimited rectangle wave
Sharp - a bandlimited sawtooth wave
For the reed/sharp voice I've created own samples of bandlimited signals for each octave. These samples are mixed at octave border to minimize the ugly "sound jump". This combination allows a much wider sound range from very soft to very harsh. To get the typical cheesy "Connie" sound you have to fiddle with theese voices. I'll do more experiments with the waveforms and the lookup tables - but my first goal was to hear some noise ;) Drawbars (vol=0..8) control the four stops, the three voices and the intensity of the vibrato and percussion.

The vibrato works as a combined stero am and fm to create a sound like a very simple leslie - massive work has to be done, maybe with the help from some experts out there...
The development moved to bitbucket.

Vox Continental

The Vox Continental creates the sound from twelve individual tunable LC oscillator boards with a six stage octave diver. The resulting 84 frequencies (RC filtered rectangular signals) are mixed with a four contacts at key press and summed for the four stops. The different voices (flute and reed) are created by summing the original mix and a two stage RC filtered signal. The fixed switchable vibrato signal (RC filtered rectangular) introduces a fm at the oscillator boards.

Find a lot of info and the organ schematics for Vox Continental.

Debian repository

You can access my debian repository. Update your /etc/apt/sources.list or put a cryptomys.list file into /etc/apt/sources.list.d:
    deb ./
    deb-src ./
After "apt-get update" get my keyring
    apt-get install horo-keyring
Now you can install connie or get the source:
    apt-get install connie
    apt-get source connie

VOX is a registered trademark of VOX AMPLIFICATION LTD..