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FATMOO is a VST synthetizer, built with SynthEdit. it works on the Windows platform, and you need a VST host to use it. aaand, VST is a trademark of Steinberg Media Technologies GmbH.

it is basically a VA type synth, but with some deliberately unusual features.

first of all, the 2 main oscillators have variable fatness. they can range from square (approx) to sin (approx) to triangle to "less than triangle" form. the knobs give visual feedback about the current waveform.

second, all the usual parameters (OSC B pitch, cutoff, resonance, etc.) as well as oscillators fatness can be modulated with an LFO and an envelope. there are 6 LFOs and 6 EGs (envelope can also be inverted on parameters), you can mix them as you like.

third, for added fun, you can phase-modulate the LFOs in chain, eg. use LFO1 to modulate LFO2 and then LFO2 to modulate LFO3 etc. the small buttons next to the LFOs headers activate the modulation.

finally, OSC B can modulate OSC A's fatness (sorta FM, but with a different meaning for "F" :-). (well, actually, it sounds more like PWM than FM).

a few notes:

  1. I tried to optimize the synth as much as possible. typical usage in polyphonic mode takes about 15% on my Thinkpad (dual core Centrino @ 1.83GHz). much less, of course, in mono mode.
  2. if you overmodulate (especially OSC B pitch) you can get very unharmonic sounds. this may even be considered a feature :-)
  3. the OSC B Pitch control is very rude: it adds volts (in SynthEdit terms) to the base pitch, so -1 is one octave lower, -2 two octaves, etc. same goes with positive values. I may replace it with something more sensible in a future version, but for now take it as it is.

comments, critics and suggestions are very welcome.


ATTENTION: some of the modulation combinations may produce very high and/or low frequencies. please keep the main volume at a moderate level to avoid damaging your audio equipment and/or ears. I can not be held responsible for any damage the synth may cause due to misuse. by downloading, you agree to be using the synth AT YOUR OWN RISK. thank you for your attention.


there is no restriction at all on what you can do with the synth and with the source code included. have fun.

hysterical raisins can also download obsolete versions:


oha for the math help (when the math gets though, this guy can really dance). Jeff McClintock for a really great piece of software. Miller Puckette and the Pd community for another really great piece of software. the KVR community and all the free VST developers around the world for all the marvelous synths and stuff. you guys rock!