Fenix IV modular synthesizer 2020-05-01T22:22:31+00:00

Fenix IV

Modular Synthesizer

All you need to play.

An intriguing set of modular building blocks

We think Fenixes are true synthesizer-instruments: they give you all the options you need to explore a very wide range of sonic possibilities. You can learn to play a Fenix quickly and you can still be developing your interaction with it in ten years’ time.  The first Fenix was born and bred to satisfy one artist’ wishes for an all in-one system. Our Fenix IV is also born out of this desire with ourselves as the artists.

The density of Fenix I,II and III meant it provided loads of sound in one box. Before eurorack boomed, most modular synthesizers required half a wall of space. Fenix provided all your options in a relatively small container. When Fenix II was released, it packed the most punch for its size anywhere on the market. With Fenix IV we think we continue this tradition.  We’ve extended the sounds by adding our best from the digital world. The intention is to provide a toolbox for you to make sound with, and not put too much of our flavour in the sounds themselves. Choices are made for maximum sonic variety. For example: we’ve upgraded the delay line from Fenix II with a musical element. In Fenix IV we are now providing a tuneable version so you can use it as a physical model of a string.

There is a flow to every Fenix. All the modules have the same direction for inputs and outputs: roughly left to right and top to bottom. This is the same in educational diagrams that talk about synthesizer structure. We managed to consistently apply this giant swipe from up left to down right across our Fenix too. You can distinguish types of signals on a Fenix by the colour coding – we’ve taken this helpful visual aid and extended it to giving the modules a coloured grouping that corresponds between the knobs and the jacks. Another feature of the Fenix family is the waterline that divides the knobs from the jacks. Keeping the knobs up top means your patching never gets in the way of your twiddling. This division also helps to maintain a sense of overview with lots of cables patched in.

We see the Fenix family as having a “Yes, and” mentality. The usual divide of tonal versus experimental or additive versus subtractive synthesis does not exist in a Fenix. You can have everything at the same time and you can have multiple  TYPES of oscillators, filters, lfo’s, envelopes and effects to do your patching with. We have added the usual analog versus digital divide to this “Yes, and“ mentality. There is no need to choose,  you can have it all.

All the modules in our Fenix IV – listed by colour grouping:

YELLOW – Oscillators and sound sources


  • Interface to external sound sources – has an envelope tracker and a gate and trigger threshold.

Fenix Oscillator

  • Oscillator from the Fenix II – classical analog multi-shape oscillator with three-way phase modulated sub-oscillator. Not that complicated. It makes sound.

Digital Oscillator

  • Unusual and usual digital oscillating algorithms. One of the four modes is a FM oscillator – we are considering the other three.

Chord Oscillator

  • Triple analog oscillator with digital chord control allowing you to patch chords: major, minor or otherwise.

ORANGE – Envelopes


  • Box standard envelope


  • The other box standard envelope


  • Hold my envelope…. Adds one more stage between attack and decay to add more punch to the peak of the envelope. Separate parallel decay stage with curves you can select. The ADSR stages are voltage controllable.

RED – Modulation

Noise & Probabilistic

  • Noise generator with adjustable probabilistic distribution. One part generates the classic analog noises: white, pink, brown, red and purple. The noise generator also has a analog sample-and-hold function. The digital part allows you to choose different distributions to base your noise one. Voltage controlled everything.


  • Fantastic advanced lfo with five waveshapes – including two physical models. We’ve released this as a separate module for eurorack. More info online.

Triple LFO

  • Plucked from the Fenix II. This is the triple-phase-shifted-voltage-controlled-triangle LFO that you know and love.

Regular LFO

  • Basic analog LFO from Fenix II with pulse and triangle outputs.


  • Classis analog slewlimiter from the Fenix II. Very useful for building portamento effects or changing modulation signals. Rise and fall are voltage controlled and switchable.

INDIGO – Filters

Ladder Filter

  • Variable slope analog transistor ladder filter. It has several outputs for various Db/oct levels.

Multiband Filter

  • Voltage controlled triple band filter that can be used to create formant-sounds.

SVF Filter

  • Inverted state variable filter with lowpass, highpass and bandpass inputs instead of outputs. This setup allows you to crossfade between sources by swapping their frequencies.

Lowpass gate

  • CV controlled low-pass gate. Makes for a smooth VCA & envelope alternative or a deep lowpass filter.

BLUE – Effects


  • Analog 9 stage phaser effect. Oh yes.


  • This module uses four adjustable levels to create new waveforms by very rapid switching between them. Instead of the levels, you can also use two incoming attenuverted signals.


  • Wave-folding soft-saturating distortion module.

Dual delay

  • Double digital delayline with various delay-themed algorithms to choose from. Reverb, delay, waveguide and chorus.

Ring modulator

  • Classic analog ring modulator. Don’t change a good thing.


  • Classic VCAs.

GREY – Utilities

Mixer 1-3

  • Three separate 3-input mixers with AC or DC coupled outputs and offset.

CV mixer 1-4

  • A selection of different CV mixers with inverters, attenuverters, offsets and precision summing.


  • CV controllable switch.


  • Forces a signal to be bigger than 0 volt.

Gate mix

  • Or-gate

Offsets & comparator

  • Dial in a level to compare to – trigger something if it is above or below that level.


  • Connect things to things.

Master output

  • 2 channel mixer with panning and VCA. Send things to your master mixing desk over the TRS jacks on the back.


Because you need sequences. Ours is an 8-step sequencer with the same step-mixing interface of the Fenix II.  You can connect steps together and use them together as an output, so you can have something happening on step 1 AND 5 on the same output.



  • Show you audio and CV signals.

USB interface

  • USB midi interface with 4 CV/gate outputs.

Time source

  • Three clock outputs with individual settings.


  • Built in to tune your oscillators to specific frequencies, and to perform calibration routines to maintain your Fenix during the decades to come.


  • Adjust your MIDI, CV and time settings.

A new member of the Fenix family – made by Stijn Haring-Kuipers and Lauri Koponen (TiNRS) with conceptual and practical guidance by master builder Bert Vermeulen (Synton/SyntoNovo).

If you want to be on the waiting list – please send an email to priscilla@thisisnotrocketscience.nl and include “I WANT A FENIX IV” in the subject.

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