EssenceFM current version : 6.3

To update your EssenceFM download the firmware below and put the file on a FAT32 or exFAT-formatted USB drive.
The file must be exactly named efm_fw.bin. Plug the drive in your EssenceFM then in Global > System, press the Update button.
After a few seconds, you will be invited to power cycle your unit.



23 May 2023

  • Clipping indicator : menu texts will be displayed in red for a short period of time if any digital clipping happens. That allows you to be aware of clipping without having to go in the Global > Audio section.
  • Added 'Pass Through' effect : passes the audio through the selected output without any processing. Makes the EssenceFM more flexible when using external effects.
  • Temperaments (microtonal scales) now do take effect globally when you're in the Global > Tuning page. That improves usability, as you don't have to edit the patch/voice you're playing to make it use the scale you're editing.
  • Added 'Remove Unused' feature for voices and patches (see Global > Sorting). That allows to automatically clear voices that are not used by any patch, and patches that are not used by any performance.
  • Fixed incorrect real-time sound update when switching between some DX7 algorithm presets


28 Nov 2022

  • Fixed wrong frequency calculations when receiving MIDI MTS tuning
  • Fixed a display bug when resetting a tuning in advanced mode
  • Fixed advanced tunings not being saved when pressing Save on another tuning (using the MultiSave "Modified Elements" popup)


26 Jul 2022
  • Saving a patch into a different slot could reset effect settings of the current performance
  • Scaling pan envelope could make the curve go out of bounds


09 May 2022
  • Setting portamento time using MIDI CC#5 now works properly
  • Muting parts in performance while a note is playing now works properly


06 Feb 2022

Demo Video
  • [More Feedbacks] All 300 voices get an additional feedback, on operator #2, with its own Level and Source parameters
  • [More Play Modes] The EssenceFM only had a single mono mode for Parts (Patches), it was "Mono on Legato", which means notes could still overlap if you didn't play legato. To bring more fun and versatility we expanded the single mono mode to four different modes in addition to the polyphonic mode:
    • MonoLP: mono on legato, portamento triggered on legato (same as before)
    • Mono: true mono, portamento always triggered (new!)
    • MonoL: mono on legato, portamento always triggered (new!)
    • MonoP: true mono, portamento triggered on legato (new!)
    Reminder: to store mode and portamento settings for various patches, use a Performance
  • [Mono Behavior] Improved playability, last-note priority now handles any number of pressed keys instead of two previously
  • [Polyphonic Portamento] Portamento now takes effect in polyphonic mode. Try stacking various Poly/Mono sounds with different portamento inside a Performance for some cool effects!
    Note: during the upgrade, your performances will be updated to have portamento set to zero for all polyphonic parts
    Important: if you import a performance made on an older version than 6.0, portamento will be heard on polyphonic parts. Set it to zero to get your original sound back.
  • [Feedback Level Smoothing] Feedback level destination in the modulation matrix now doesn't produce stepping when modulation ratio is super small
  • [Operator Volume Smoothing] Quickly changing operators volume using the touch screen does not produce clicks anymore. Also, controlling operators volume via the modulation matrix is smoother
  • [Realtime Editing Improvements] Voice Volume, Transpose and Tuning parameters now takes effect immediately without needing to retrigger the note
  • [Envelope Point Alignment Helper] An horizontal line shows up when the envelope point you're moving is aligned with other points. That helps you finding the perfect position for envelope loops.
  • [Preview Button] Pressing Preview on patches that have no layers responding to the preview notes will play the first available layers. This is useful to make the preview button work on drum kits.
  • [Modulation Matrix] Added "Alternator" source. Alternates between 0 and 127 on each key press. Will you find uses for it ?
  • [Modulation Matrix] When setting up a new modulation, Source and Destination are both prompted instead of having to set them separately
  • [Modulation Matrix] Added filter envelope point Y positions as destinations
  • [Envelopes] Horizontal and vertical stretch feature for envelopes
  • [Voice/Patch List Export] In Global > Storage > Export you can export the full patch and voice list as a text (CSV) file
  • [Sound Engine] Operators' frequency is 64 times more accurate than before - Helps preserving a nice phase sync between operators
  • [DX7 Voice Import] Vastly improved DX7 voice import, although some parameters remain unsupported or with major differences. A lot of banks can be downloaded here: Try it!
  • [USB File Selector] Folders are displayed first, then files, all sorted by alphabetical order
  • [LFO Display] A cursor is displayed on the LFO waveform to show its current position
  • [Note Stacking] A new feature called "Prevent Same Notes From Stacking" is available in Global > Audio > Options, it allows the EssenceFM to behave more like an acoustic instrument where you can always have a single instance of a note at the same time. This also reduces polyphony usage on trills and may make the sound cleaner depending on what you play.
  • [Save behavior] Pressing Save now always shows the 'Save As' dialog, asking you if you want to overwrite the current element or save it to another location. Press Save again or press Ok on the touch screen to confirm.
  • [Edition Buffer] Before this new version, if you edited an element that was already edited but not saved, then tried to save it to another location ('Save As'), the initial element was resetted to its original state before any edition. Now this doesn't happen anymore, because the EssenceFM always keeps a copy of the element each time you edit it.
  • [Copy] Pressing the Copy button shows a quick message on screen to confirm it worked
  • [Synced Delay] Long Synced Delay replaces Long Tap Delay. The new delay is MIDI-syncable and can have its delay time changed smoothly, doing that will create a cool tape-like pitch effect, very noticeable if you change the length manually. The 'Tap' parameter does not exist anymore. When MIDI Sync is enabled, difference between L/R delay parameters is used to create a slight stereo effect.
  • [Fractional Multipliers] For each operator, the Frequency Multiplier parameter can take fractional values (1/2, 1/4, 1/8 etc.), making low ratios much easier to get than before
  • [MIDI Clock] More accurate BPM calculation from MIDI clock

B revision

  • Alternator works on patches with any number of layers
  • Envelope scale doesn't slightly lift bottom points anymore
  • Percentage parameters can also be resetted (to 100%) by double tapping on them

D Revision

  • Bug fix when using more than 64 events in the Voice Sequencer


11 Nov 2021

Features / UI

  • [Mono outputs] In performance mode, parts can now be assigned to any mono output (1L, 1R, 2L, 2R, 3L, 3R, 4L, 4R) in addition to the stereo pairs. In mono mode, panning is ignored.
  • [Envelopes] Moving the first point doesn't scroll the display anymore (prevents unwanted scrolls)
  • [Envelopes] Clearing a voice resets all volume envelopes to an ADSR-like shape for quicker editing. Pitch envelopes are reset with a segment before and after sustain. Units made with this firmware pre-installed come with all empty voices configured with these envelope shapes. If you want to get this on your updated EssenceFM you need to clear a voice then copy-paste it to all other empty voices. To make the process easier you can:
    • Press Dec then Paste multiple times to quickly overwrite all 128 voices from a bank
    • Copy whole banks by doing Copy-Paste in In Global > Sorting > Voice Bank
    Once you've overwritten all empty voices press the Voice button to get to the voice list, then press Save two times to save all edited voices. Note: saving a lot of edited voices can take a few seconds.

Bug fixes

  • [Panning] Panning can now go to 100% right
  • [Startup] Fixed a bug that could freeze the EssenceFM at startup
  • [Patch] Modifying the Round Robin parameter when the patch isn't edited yet do not reset its value to 1 anymore
  • [Misc] Display bug in Patch > Effects and Voice > Effects introduced in v5.3


22 Jul 2021


  • [XY Controller] Use the touch screen as an XY controller (Global > TouchPad). Both axis can be configured to send Control Changes internally or though MIDI out. It can control any FM parameter (via the Modulation Matrix) and effect parameters (CC47-93, see user manual).
  • [Layer Morphing] Morph between up to 4 layers inside a Patch, manually or using an orbital LFO. Morphing works by moving your finger on the touch screen or by using setting X/Y Speed and Depth parameters for the orbital LFO. Morphing is made for live use, its LFO settings aren't saved in the patch. Using fast speeds with pure sounds may exhibit volume stepping noises.
  • [Waveform List] Option to listen to the currently playing voice/patch while editing waveforms (instead of listening to the waveform alone)
  • [Waveform Editor] Fold-Back distortion was added as an additional tool to shape your waveforms. Press the Gain button then check the Fold-Back box to use it.
  • [Waveform Editor] Waveform area selection can be done by turning Knobs 1 & 2
  • [Modulation Matrix] Envelope segment durations can now be controlled even for segments located after the sustain point
  • [Modulation Matrix] New "Common RNG" source. Generates a single random number on Note On which can be used on multiple slots of the modulation matrix (the already existing RNG source generates a new number for each slot)
  • [Aftertouch] Aftertouch smoothing (Global > MIDI). Greatly reduces audio artifacts with MIDI controllers that send too few aftertouch messages.
  • [MIDI Player] Independent volume control for MIDI file playback
  • [Effects] BPM indicator for Delay and Long Delay effects
  • [Voice Editor] Reaching the Quartertones parameter bounds automatically increments/decrements the Multiplier, also reaching the Fine parameter bounds automatically increments/decrements Quartertones. That allows you to explore a wide range of operator frequencies without having to switch between parameters.
  • [Voice Editor] Pressing Copy on the voice editor when nothing is selected will copy the whole voice. Also works for Paste.
  • [Voice Editor] Operator frequencies are now displayed in the operators. Can be disabled by unchecking Op Frequencies in Global > Display
  • [Voice/Patch Editor] Undo/Redo is less confusing by considering tab change as an undo/redo step (editing something on tab A, then doing a change on tab B then pressing Undo won't immediately bring you back to tab A)
  • [Lists] Option to disable wraparound when scrolling lists (Global > Display > Input)
  • [Patch List] Button to show which Patches are used in Performances

Bug fixes

  • [Misc] Positive key scaling, negative velocity scaling and RTP-MIDI did not work correctly in v5.0
  • [Voice Editor] Modifying voice frequency parameters while using the Scale Override feature (patch) updated currently playing notes with wrong pitches


30 Apr 2021


  • [USB Host] Hot-plug support for USB drives and MIDI controllers
  • [USB Host] Improved compatibility with many devices including the Roli Rise and Seaboard
  • [Shimmer Effect] Improved sound quality
  • [Waveform edition] Phase shifting for waveforms
  • [Patch] When using round robin, you can now assign a value of zero to a layer to make it play everytime
  • [Modulation matrix] Controlling an operator's volume via the modulation matrix no longer ignores velocity. The update will automatically process your sounds to set Velocity Sensitivity to zero on operators that have their volume controlled by the mod matrix, to make sure your Voices sound the same after the update
  • [MIDI Sync] Voice Sequencer and LFOs now use their default tempo when MIDI Sync is enabled but no clock is received
  • [LFO MIDI Sync] Slower sync values for LFOs, down to 16 quarter notes
  • [Screenshot] Press the four quadrants of the screen to take a screenshot
  • [Voice Sequencer] Latch feature. Press Latch to keep the next notes active while you tweak the sounds or play other instruments. Stop it by unchecking the option, pressing Panic or releasing the sustain pedal
  • [Voice Editor] Muted operators now have their envelopes started, you can use them as modulation sources in the mod matrix. (this was previously possible only by setting an operator's volume to zero)
  • [Microtunings via SysEx] Non-realtime MTS (MIDI Tuning Standard) messages are supported. Go into Global > Tuning to allow reception.
  • [Aftertouch] Monophonic and Polyphonic aftertouch are now merged together in the modulation matrix
  • [Tunings] Master Tune now takes effect when using Advanced Tunings with fixed frequency notes

UI Improvements

  • [Save] Convenient save system: pressing Save on an element will automatically save all related elements (patches used by a performance, voices used by a patch, waveforms used by a voice...)
  • [Save] You can now 'Save As' an element even if it has not been modified
  • [Lists] Double-tap on Patch/Voice/Waveform lists to go into Edit mode
  • [Parameters] Double-tap on any parameter that has a center value (Pan, Tuning etc.) to reset it
  • [Performances] Switching performances now immediately takes effect when pressing on the list
  • [MIDI Sync] Clock dividers are now shown in a more musical way (quarter note divisions)
  • [USB Audio Rendering] Output file name is automatically incremented each time you do a new recording
  • [USB Mouse] If your can't easily access your EssenceFM to use its touch screen, you can plug a USB mouse to control it. The left click act like a press on the screen, while the right click provides access the physical key functions via a menu
  • [Patches/Voices List] Indicator to show which patches/voices respond to aftertouch and mod wheel

Bug fixes

  • [LFO] Didn't start at the right phase offset when used with Delay parameter
  • [Voice Sequencer] In looped mode, the Voice Sequencer looped 1 step too early
  • [Voice Sequencer] Wrong BPM when not sync'd to MIDI clock
  • [Filter] Releasing a key while controlling filter cutoff via the mod matrix created a jump in the sound
  • [Stuck notes] Stuck notes while switching from Mono to Poly mode via MIDI (CC 126 and 127) and while using USB-Host devices with other MIDI sources at the same time
  • [Import] Some Scala files weren't imported correctly
  • [Import] Importing a performance from USB while having the EssenceFM in Patch/Voice mode could mix up perf/patch/voice associations under some circumstances
  • [Voice List] Pressing 'Create Patch From' for voices with long names could freeze the unit

Other changes

  • Reset Page removed. Replaced by the backup feature introduced in the previous version. You can download the EssenceFM factory backup on this website in the Support > Sounds section, load it then choose which elements to save after your loaded it.
  • A single font is now enforced, to prevent alignment issues due to different font widths


13 Mar 2021
  • Full backup: unlike the Import/Export feature which helps sharing and fitting new sounds into existing banks, backups allow you to save and restore everything in your EssenceFM. It can be used as an additional security or to copy all your work from an EssenceFM to another one.
UI Improvements
  • [Envelope Editor] Scrolling automatically follows when envelope points are moved out of the viewing area with the knobs
  • [Voice Editor] Randomizing a sound and using Undo/Redo keys updates volume envelope and algorithm in real time
Bug fixes
  • [Modulation Matrix] Polyphonic Aftertouch wasn't useable with Patch Transpose
  • [Voice Editor] Pressing the Undo key when no operator was selected could randomly mute the EssenceFM
  • [Voice Sequencer] Freeze when hundred of events were triggered at the same time
  • [Patch] Corruption when a whole patch bank (128 patches) had more than 8320 layers in total
  • [Effects] Long Tap Delay did not sound exactly like it should


17 Feb 2021
  • Multimode filter with morphing capability between high pass and low pass modes, controllable via the modulation matrix
  • 48 user waveform slots instead of 24
  • The Voice Sequencer has the ability to keep its instances synchronized with each other, allowing you to play chords while keeping the patterns in sync
  • Scale override at the Patch level. Takes priority over the voice scale.
  • On-the-fly algorithm swap available as a modulation matrix destination. Selects between the 32 algorithm presets.
  • True mono mode at the layer level: the "Exclusion Group" feature can be configured to either soft-cut or hard-cut the notes, like on a monophonic synthesizer.
  • MIDI LFO sync ratio (clock) has been added to the modulation matrix destinations
  • New "Free Running" mode for operator phases, useful to use operators as LFOs
  • Added support for sostenuto pedal (CC 66 - only sustains notes that were held before pressing the pedal)
  • Added support for MPE in Patch and Voice modes. Select "Omni/MPE" for the Global Channel setting in Global > MIDI to enable it
  • New visualization system in Global > Audio allowing you to see all parts, their notes and allocated voices
  • Voice randomization: option to separately randomize the LFO
UI Improvements
  • Events in the Voice Sequencer can be moved using the main jog wheel
  • Ability to copy/paste between different envelopes types (volume, pitch, filter, panning)
  • Voice editor: Zoom scale on envelopes stays identical when switching operators
  • Voice editor: Double-tap operators to mute/unmute them
  • A default name is enforced when a new element (empty slot) is being edited
  • Waveforms can be moved to other slots
  • Black theme: better looking menu bar
  • New startup animation
  • Patch editor: indicator for currently playing layers
  • Very rare double-triggered key presses are prevented (improved debouncing)
Bug fixes
  • USB import no longer freezes when importing items without any free slot available
  • Modulation matrix: Pan as a destination didn't go up to 100% left / 100% right and didn't work in combination with RNG source
  • Performance/Patch mode: Importing a performance/patch from USB into the currently used performance/patch slot did not immediately apply effects
  • Exclusion Groups did not work under some circumstances (envelopes in Linear mode with Sustain Point set on the last point)
  • Voice allocation display glitch
  • Undoing a category change for patches/voices did not immediately update Patch/Voice lists
  • Copy key did not work on all text elements
  • Slight distortion noises could get into some notes while playing
  • Using very short filter envelope loops combined with resonance doesn't stops the EssenceFM from making any sound anymore. The filter will self-oscillate instead (it's usually not desirable to use it like that, since it will be loud and saturate the outputs)


26 Sep 2020
  • New effects: shimmer, long tap delay, mono mix
  • New graphical interface:

    The firmware update will show you the new theme. If you don't like it go into Global > Display > Appearance and re-select your previous theme. You might also re-select your background pattern and color settings.
  • Packed import/export system: multiple elements can be saved in a single file and imported into another EssenceFM while keeping the relations between elements (voices in patch layers, waveforms used by voices etc.)
  • Advanced sound randomization: choose to separately randomize frequencies, filter, volume envelopes, pitch envelopes, volumes and algorithm
  • Save As: keep the Save button pressed for 1 second to open the Save As dialog. A short press does a regular save like before
  • Filter Dry/Wet parameter was added to the modulation destinations
  • Multiple Recall was implemented, it works like Multiple Save to quickly find which elements you edited and recall them
  • Pressing the Perf/Patch/Voice buttons while you're on a sub-page brings you to the main page
Bug fixes
  • No more stuck notes using MIDI-RTP on Apple computers
  • "Solo" button in patch editor didn't work properly with more than 6 layers
  • When using a MIDI-USB controller plugged into the front USB port, events from the Voice Sequencer could very rarely miss their note off
  • Performance parts could be muted by pressing simultaneously Perf and Global buttons.
  • Some radio buttons didn't worked properly in firmware versions 3.1, 3.2 and 3.3
  • "Bank Change" enable/disable on Performance Parts wasn't handled correctly
  • Using the "Random Sound" feature cleared the modulation matrix without refreshing its display (now it doesn't clear the mod matrix anymore).
  • Receiving MIDI commands that modify the current Performance settings (Volume, Pan etc.) while saving could make the EssenceFM think the Performance is corrupted.


18 Jul 2020
Features/Bug fixes:
  • Advanced microtunings: choose arbitrary frequencies for each 128 notes
  • Lossless audio rendering to USB drive (.wav, 16 or 24 bit)
  • MIDI clock (BPM) as a modulation matrix source
  • More FM parameters are updated in real-time as you edit the sounds
  • Envelopes loops can now be set be after the sustain point
  • Inc/Dec buttons allow to move the cursor in the naming page, they also work for navigating into the Voice Sequencer events
  • Default behavior for the expression pedal can now be disabled (controls volume)
  • Fix: expression pedal MIDI filter wasn't working
  • Fix: in some rare cases, booting with a MIDI-USB device plugged in the front USB port could mix up the outputs assignations
  • Fix: freeze when touching the screen during boot, and on some algorithm configurations


09 Jun 2020
Features/Bug fixes:
  • Scala file support
  • Fix default voices using free waveform slots instead of waveform #0 (Sine) - If you changed those sounds or fixed them by yourself, it won't do anything.
  • DX7 32-voice and 1-voice sysex dump support via USB
  • 'Turn off' screen after a delay now works as expected and also shuts down the key backlight
  • Better detection of USB drives and USB-MIDI controllers
  • Real time envelope update when editing
  • In the modulation matrix, max ratio is now 400% (instead of 200%)
  • Global > MIDI: MIDI file player
  • LFO is now syncable to MIDI clock
  • Envelope loops can loop forever if you omit the sustain point
  • Global > Audio: Option to disable waveform interpolation
  • Larger range for pitch envelopes (8 octaves)
  • Algorithm navigation with the main wheel
  • See/edit all part volumes and pans on a single screen by pressing Performance two times
  • Fixed a bug where the sustain point was ignored in combination with mod. matrix changing the envelope speed
  • Globlal > Display : Angle compensation feature (contrast) for people having the EssenceFM lower than their eyesight.
  • Fixed a rare crash that could happen when removing/editing modulation matrix entries
  • Fixed a bug where performance effects could end up overwriting patch effects
  • New background patterns and color themes
  • Better support for exotic Wave files for import
  • Mute/Solo buttons for operators and patch layers
  • More digital gain available to boost output volume
  • Switching between Global and other modes now remembers the current page you were in
  • Many, many small ergonomics improvements

MASK1 current version : 3.5

To check which firmware is already installed on your MASK1, power it on while pressing the last two black keys. Current version will be displayed on screen. Press Param >> to acknowledge.



23 May 2024

  • Fixed OSC2 mask loop not working in normal mode
  • Fixed CC 56/57 not working (OSC1/OSC2 mask loop mode)



See below for installation instructions


05 Mar 2024

  • 512 different masks available instead of 256. Masks ranging from 256 to 512 are very unique and pulse-like, offering more sonic possibilities.
  • Editing both oscillators at the same time is now possible. Press both buttons simultaneously. The first button pressed sets which value is used as reference for editing, exactly like how the multi-envelope editing already works (eg. if masks are respectively 15 and 60 for Osc1 and Osc2, press Osc1 first to start from 15 when turning the knob, or Osc2 to start from 60).
  • Added a second 12dB filter on each voice. You will find its parameters under the name EXTRA in the filter section. When EXTRA = 12DB, the second filter is disabled. When set to 24DB, it is combined with the first filter to form a very characterful 24dB filter. The following modes (LP1-7, HP1-7) sets the second filter to fixed frequencies and modes independent from the first filter. This is to allow some sound shaping (eg. lowering highs when the main filter is used in high pass mode).
  • Added keyboard tracking parameter for the noise sample-and-hold generator.
  • Keep the VOICE button pressed and press OCTAVE+/- to change the voice used by parts 2-4 (before this update, this was only possible using program changes). Release the VOICE button to return to part 1. Voices for all parts are kept into memory.
  • New LOOP parameter for each oscillator. It makes the mask's delta envelopes loop indefinitely. Possible values are OFF (disabled), ON (mask is resetted to its initial value when delta envelope reaches its end - like a sawtooth LFO), BIDI (mask sweeps back and forth - like a triangle LFO)
  • LFO buttons light up to show LFO activity (can be disabled in GLOBAL if you do not like that)
  • Navigate faster in the voice list by keeping VOICE pressed while you scroll (+10/-10 increments)
  • LFO now fades in more progressively, in a more musical way as you increase the delay (DLAY) parameter
  • 600 user memory slots instead of 400
  • Cutoff reacts faster when quickly turning the knob
  • Fixed CC 25, 26, 27 and 28 (envelope levels) not received over their full range through MIDI. Filter envelope is a special case where zero corresponds to CC value 64. This is to allow access to negative values.
  • Fixed MIDI clock not received through USB
  • Some presets have their default LFO modulation lowered
  • New MIDI CCs were added to allow for external control of these new parameters, check the updated user manual


11 Jul 2023

  • Fixed ignored notes received through MIDI when disabling Local Keyboard


20 May 2023

  • Total polyphony is up to 12 voices instead of 10
  • Improved oscillator quality
  • Numeric display for the volume level
  • Improved factory voice presets


07 Apr 2023
  • Improved factory voice presets
  • Fixed freezes happening with the arpeggiator
  • Improved arpeggiator behavior with sustain pedal and live editing

How to update (PC)


Extract the ZIP file on your computer. Ensure the path contains no parenthesis. Follow the instructions in the PDF.

How to update (Mac)


Ensure you're using Chrome or Firefox. Install Java Runtime Environment if you do not already have it on your system.


Download the STM32CubeProgrammer utility, extract the ZIP file and install the software


Power on your MASK1 and connect it to your computer using a USB cable


then wait until this indicator turns green :


Launch STM32CubeProgrammer


On the right side, select USB* for Port then press Connect


On the very left side, press the second icon. Press Browse to select the firmware file (.bin) you downloaded.
Ensure the same boxes are checked as on the picture, then press Start Programming


After a few seconds, a popup shows that the connection was lost. This is normal. You can now disconnect the USB cable and close the program. Your MASK1 is ready to use.

If this procedure did not work and the MASK1 is stuck with a black screen, disconnect and reconnect its power supply, refresh this page and try again.
Never disconnect the power or USB cable during an update.