Rack Extensions by Synapse Audio

Synapse Audio offers a choice of high quality rack extension plugins, tailored to Reason.


antidote - frontside

antidote - backside

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Antidote RE is a brand-new virtual-analog software synthesizer for Propellerhead Reason. This Reason-exclusive device manages to combine the highest audio quality, flexibility and a fast work flow in an extremely easy-to-use Rack Extension. Antidote has been specifically developed to complement Reason, and to perfectly integrate into its environment.


Antidote RE comes feature packed with two stereo oscillator banks, each emitting a stack of up to 50 virtual-analog oscillators per voice, in highest audio quality. Conventional synthesizers cannot even reach that in unison mode.  With all voices active, Antidote delivers up to 800 stereo oscillators. This oscillator power is not a gimmick, but a requirement to synthesize typical sounds found in today's dance music. Until now this was only possible with very few synthesizers, mostly hardware.

The available oscillator shapes not only comprise classic analog waveforms such as sawtooth, pulse and triangle. Each oscillator type has an additional feature (called a “Modifier”), which allows to apply extra features such as hard sync, pulse width modulation or to blend between different waveform shapes.


Antidote employs a multimode filter with the latest zero-delay feedback designs. This recent technology models the highly sought after sound of analog filters much more faithfully than previous designs. When adding resonance, in particular, the behavior of the filters is much closer to vintage analog hardware.

Filter designs in Antidote comprise the OTA low pass ladder, a filter topology frequently seen in analog synthesizers. Low pass roll offs range from 6 to 24 dB, so that anything from deep fat basses to thin bright sounds can be synthesized. The low pass filter reaches self-oscillation and is properly tuned, so that the filter can be used as an oscillator at high resonant levels. Two derivative filters yield a 12 dB bandpass and high pass response.

A unique feature in Antidote is the diode ladder filter, which models a rare analog filter circuit composed out of diodes (or transistors hooked up as diodes). This filter topology is widely known from the famous "silver box", and responsible for some unforgotten classic analog sounds, like growling basses and squelchy leads. To the best of our knowledge, this filter topology has never been realized before in a polyphonic synthesizer such as Antidote.


Three envelopes, two LFOs and the arpeggiator further shape the sound. The powerful modulation matrix, which can modulate almost any sound parameter, adds the necessary depth to realize complex sounds. Furthermore, CV inputs on the back panel can be used to modulate any sound parameter from any Reason device - the sky is the limit!


The arpeggiator module in Antidote features the well-known classic modes (up/down/...), with 20 preset rhythms to choose from. But there's more to it, of course - the arpeggiator both emits a gate and an accent signal, freely usable as a modulation source.


One of the big strengths of Antidote is its massive effect chain, which contain some of the best effect algorithms from Synapse Audio. A total of 8 effect modules is available, all of which can be used simultaneously.

EQ and Bass: A classic three-band EQ design followed by a bass enhancer. The bass enhancer is modeled from circuits found in some legendary analog synths, and allows Antidote to mimic their bass response. A simple yet invaluable tool to create fat analog bass sounds that cut through the mix.

Distortion: Full stereo distortion effect using 4x oversampling to minimize aliasing noise. Tone, Low- and high-pass controls can be used to further refine the distortion timbre at the output of the effect.

Phaser: 4-stage stereo phaser, based on the Synapse AP-12 phaser technology.

Chorus: Stereo chorus effect with adjustable delay time and feedback, allowing the unit to be used both as a chorus, as well as a flanger effect.

Delay: A comprehensive delay section with separate L/R controls, a color parameter for low/high pass echoes, and a modulation section to create a full, lush stereo delay sound.

Reverb: The reverb unit is based on the Synapse DR-1 rack extension, a modulated true stereo reverb modeled after high-end hardware. Its sound character is especially well suited for synthetic sounds and works exceptionally well on lead sounds.

Compressor: The smooth stereo compressor allows instant level reduction with attack times ranging down to the microsecond range, while minimizing artifacts as much as possible, and without introducing any latency.

The effect processor in Antidote can be used with external sources as well, and was designed with that option in mind. As a result, the processor intensive effects such as the reverb do not use any CPU when idle.

Built in content

Antidote comes with 500 patches sorted into the common categories (Arpeggiated, Bass, Lead, Pads, etc.) as well as 10 Combinator patches.

Update v1.1

- Wavetable synthesis added, with 8 different wavetables to choose from.

- Phaser can now be switched between 2, 4 and 6 stages.

- Rate Crush effect added to Distortion section.

- Key Follow source added to the modulation matrix.

- Performance improvements and bug fixes.

- 200 new patches added.

Update v1.2

- Sallen-Key low pass filter type added to the filter section.

- Two more wavetables added to the oscillator section.

- Reverse Delay effect added to the delay section.

- Back panel gains CV Outputs for both LFOs and all envelopes.

- New patches added.

Update v1.2.1

- Note/Gate CV inputs did not always work properly when connected to other Rack Extensions, fixed.

Update v1.2.6

- Three new wavetables added.

- Improved knobs.


About Synapse Audio

Synapse Audio has created software for professional music producers since 2000. Our focus is top-notch sound quality, as well as usability. Being musicians ourselves, we like to use tools that help us get our ideas realized quickly, without being slowed down by convoluted workflows.

Our products

Obsession - Analog Modeling
Obsession Cinemagic
DUNE 3 - Virtual Analog
World of Sequences
The Legend - Analog Modeling
The Legend Modern Analog
World of Cinematic Vol. 2
Downtempo Metropolis
Premium EDM Vol. 3
World of Ambient
Big Room
World of Cinematic
Premium Trance
Premium EDM Vol. 2
Premium EDM Vol. 1
Hydra - Multimodel FM synth
EKS Pro - Kick Drum synthesizer

Our Rack Extensions

 Obsession RE  The Legend RE  RE-160 Compressor  Fat Space Reverb  RM-1 Ring Modulator  AF-4 Analog Filter  DC-2 Dual Chorus  DR-1 Deep Reverb  AP-12 Analog Phaser  VE-3 Vintage Equalizer  Ninety Vintage Phaser  GQ-7 Graphic Equalizer

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