KrOn is a DSP and CV modulator allowing to control Scope Synths, Eurorack Modules and Hardware Synths which include CV inputs. It is compatible with V/Oct, and includes two modes for the Korg MS20 family (absolute and relative Hz/V). It is also pitch-compatible with VSTi thanks to the +12dB gain output (VSTi may need to work standalone to receive external signals. This was tested with VCV rack and Voltage Modular in standalone modes).

KrOn also includes Midi to CV conversion functions, saving the need for a Midi to CV converter. KrOn can convert Midi Notes, Aftertouch, Midi Control Changes, Key Follow, and more. It even includes a dedicated vibrato controller. Most midi signals can be smoothed to get rid of any scaling/quantizing with included envelope followers that can be set to various values by the user. 

If it was not enough, two audio inputs with envelope followers allow to use external modulators from Scope, VST, or Eurorack world and to mix them with the included modulators. That way, it becomes easy to create envelopes, modulations or triggers with any sound from your track, and to send all these modulations to one or several synths through the 8 outputs of KrOn.

You can also sync several KrOns and CV Synths together thanks to the “KrOn Sync” i/os, that allow to set the tempo once and for all on KrOn, and to transmit this tempo to all connected devices (requires compatible devices because of the calculations involved). Of course, KrOnSync is a choice, choice, and you can still use the internal bpm of each devices or your external midi clock equipment.

To work with CV hardware, KrOn requires an Expert Sleeper ADAT to CV interface (such as the ES-3, ES-8, etc…). Other interface may work or not depending on their calibration, but as long as it supports 1V/Oct, it should not be a problem. KrOn is also directly compatible with the MS20 signal follower (ESP) without the need for an Adat-to-CV converter if you just w ant to modulate the Cutoff and trigger the envelope of the MS20 (controlling the oscillators Pitch requires a CV signal on the MS20). To achieve “Perfect-Pitch” the destination oscillator(s) needs to be compatible with 1V/Oct or Hz/V, which is the case with most current hardware from major manufacturers.

If you do not own Hardware synths/Eurorack modules, KrOn comes with a few great Scope Synths to get you started immediately. KrOn “Max Pack” includes extra synthesizers with advanced features. Check the manual for more information (also included in the installation zip file). Also, check our “News” section as more functions have been added recently. KrOn is also the perfect companion for the S|C Prodyssey CV which includes 4 inputs for external signals, as well as BlackBox III osc&Filters.

Quick Examples

A few videos showing KrOn in action with hardware synths. Please forgive the quiality of the videos, made during the building of KrOn.
Refer to the soundcloud examples for a better quality.

KrOn+MS20+Minitaur. It is easy to control V/Oct and Hz/V with a single KrOn.  The MS20 has pitch and trigger controls, while the Minimax uses pitch and 2 envelopes with a delayed start, that modulate the filter and trigger the envelopes.

KrOn comes with a Midi-Note to CV extension allowing to convert any Midi keyboard into a CV keyboard. Here, it plays an Erika Synth Pico VCO that goes into the MS20 Filter. It is fast and accurate, and is available as freeware for all (see below for download link).

KrOn is great for Scope DSP Synths. Here with the FMZ “multi-synth”, ie 3 independant synths into the same device. KrOn+FMZ transorm your Scope into a multitimbral analog workstation. 

DSP Synths included with KrOn

KrOn comes with a few DSP synths, and is also compatible with the Sonic Core Modular Synth II, III, and IV.   The singularity of SpaceF CV Synths is their minimal use of included modulators, because all will be controlled by KrOn. They all include VCA and Filter Enveloppes and they rely on KrOn for LFOs, step sequencers, extra Enveloppes, Key Follower, Aftertouch, and many other modulators. This system allows synths to share common modulators and to run along hardware synths and Eurorack modules, and your DAW, in perfect sync.


its simplicity hides a fat and agressive analog-like synth. Volcano can be modulated by KrOn, by audio signals, By Scope Modular, or by hardware modulators from your Euroracks modules or hardware synths (with or witrhout the need for a “CV to Audio” conversion, depending on each modulator).


JunZ brings Volcano a step further by adding “Juno-style” oscillators and filters, a filtered noise generator and a sub with selectable shape.

Mini FMZ

MiniFMZ is a single FM Operator from the FMZ “multisynth”. All sections can be CV controlled.  The video shows it played standalone ( with midi keyboard/DAW Midi, i.e. no KrOn).

More free Devices

These devices are great extensions to KrOn and are available as freeware or as additions

K16 is a Blackbox III Modulator that is free for all KrOn and KrOn Max Pack users. 

Logiquencer was made to trigger the Korg MS20 through its signal follower (no need for Audio to CV converter). It can also provide triggers for Scope Synths.

Modular Patch with oscillators and filters modelled after Sequenctial Circuits vintage synths.

Convert Midi notes and Pitch Bend to CV. Supports legato Portamento.

It is included with KrOn and KrOn Max Pack, and you can also download it for free from PlanetZ Scope forums


KrOn Max Pack

The following synths are part of the “KrOn Max Pack” and can also be purchased on their own.


FMZ includes 3 FM Operators and can be used to create multitimbral sequences that will bring Scope into the territories of the best workstations. 

Advanced functions are such as the different pitch bend and portamento “per operator”, the VCA triggers and amp modulation, as well as the mono and stereo insert slots and 3 stereo outputs in addition to the main outputs


Magma is all about its parallel multimode stereo filters and special selection of oscillators that can give either soft or growling sounds. It includes two extra LFOs and 2 modulation adders to mix internal modulators and CV inputs together.

Check the video showing Magma and JunZ for a demo that is worth a million words.


Spirit comes free with FMZ .  It contains an FM Operator and a VA oscillator feeding ring modulators and a set of filters with Lowpass and formant capabilities.

It also includes 21 CV inputs to control filters and Amp of almost every section of the synth. Spirit is great to create 5-tracks sequences of FM, Ring and noise tones.