SY66 is an advanced Phase or Frequency Modulation (FM) synthesizer for Native Instruments Reaktor.  It can be played with a midi controller, or your own voice and comes with a wide assortment of sounds designed to take advantage of a standard 8 knob hardware format.  These macro knobs control different aspects of the synthesizer and give the artist and performer a chance to be creative without being mired in details and parameters.  Just load, play and twist for fun!

New in version 1.5: Zero Delay Feedback Ladder and State Variable Filters. New knobs and controls including separate unipolar and bipolar knobs. Master Level control with brickwall limiter and soft-mute. New sounds and updates to existing sounds. More macro control assignments for quick sound design and performance. Modwheel integration into most sounds for direct control. Updated manual, bugfixes and structure improvements.

Instrument designed, built and documented by Jonathan Adams Leonard and including work by Martijn Zwartjes, Stephan Schmitt, Max Zagler, and Eric Wiegand.

You can hear demo tracks of SY66 on Soundcloud

SY66 v1.5 may be downloaded here.  (requires Reaktor v6.0)

Online Manual

If you find SY66 useful in your music productions or sound design work, please make a donation to support updates and future capabilities via paypal to

10 thoughts on “SY66

  1. Jim Hurley says:

    Great job and great sound.

  2. Si Robinson says:

    Nice work! I’ve only played with a couple of presets and made slight changes, but it can certainly come up the (sonic) goods. I look forward to spending more time with it.

  3. bluedad says:

    Sounds fantastic! Hope to spend more time with it.
    Nice work, thanks.

  4. Ryan Dean says:

    Truly a work of beauty. I feel so inspired every time I work with this synth and the sounds it produces are beyond comprehension.

    Cant thank you enough!

    • jonathan says:

      Hi Ryan, thanks for the kind words! I am still working on the fix that you mentioned. The issue is entered with NI.

  5. […] Download SY66 here. […]

  6. Fantastic sounds – immensely inspiring ensemble! Many thanks for creating and posting it on the Reaktor Forum Jonathan!

  7. […] Module has released version 1.5 of SY66, a free synthesizer instrument for Native Instruments […]

  8. Thank you for your work on SY66 and for sharing it! I am truly impressed with the SoundCloud demos of it and have now downloaded it.

    And I think you have given me a good reason to finally update to Reaktor 6. 😀

    Best to you!
    Shannon McDowell

  9. Aesthete says:

    Danke !

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