Firmware Files and Release Notes (ER-301)

Rapid development in Progress! 
The ER-301 is undergoing frequent firmware releases.  There is a bug report and feature request discussion happening over on the Forum.  Your input is greatly appreciated!

How to install firmware on the ER-301:
  1. Download the zip file from one of the links below.
  2. Copy the zip file (without unzipping) to the FRONT microSD card.
  3. Power up and insert the microSD card into the FRONT slot of the ER-301.
  4. Move the STORAGE switch from EJECT to ADMIN (i.e. mount the card).
  5. Navigate to the UPDATE FIRMWARE screen (all the way to the right).
  6. Press UPDATE.
  7. Select the zip file that you copied in step 1.
  8. Once the files are installed, press REBOOT.
There is a possibility that quicksaves and presets made with a newer version of the firmware are not backwards compatible. So to be safe you should make a copy of your ER-301/sc directory before switching to a newer firmware.

v0.2.x (unstable)

I am working on the next firmware release.  You can try it out and read about it here: v0.2.x Release Thread

v0.1.6p15 (stable, last updated May 12, 2017) 96kHz or 48kHz

You can choose either the 96kHz firmware for highest fidelity or the 48kHz firmware for the greatest number of simultaneous units.  I plan to add the ability to hot-switch between 96kHz and 48kHz using one firmware but for now you can just keep both firmwares on your uSD card and switch between them using the 'Update Firmware' screen.

The pre-release discussion thread (soon to be closed) for this firmware version is here.


  • INVISIBLE: Rewrote the underlying GUI framework to make it more amenable to plugin development.
  • INVISIBLE: Big changes in the audio engine were done to get ready for the upcoming bus units.
  • FIXED: button debouncing time was incorrectly configured resulting in little to no debouncing.
  • FIXED: audio dropout when inserting LIMITER unit
  • FIXED: upon activation, input channel selection UI resets to collapsed state
  • FIXED: SAMPLE PLAYER's fade time parameter not getting updated when moving fader and stereo sample is loaded
  • FIXED: fixed potential race condition when deleting slices (hard to test though)
  • FIXED: zipper noise when changing modulation gain/bias via knob
  • FIXED: WET/DRY parameters were not clamped to [0,1]
  • FIXED: some obvious parameters were not being set when loading a mono in preset into a stereo context (and vice versa)
  • FIXED: when parameter is focused, pressing CANCEL now restores the original value (rather than zeroing it)
  • FIXED: bouncing cursor does not match selected spot sometimes
  • ENHANCED: slice offset parameter added to SAMPLE PLAYER
  • ENHANCED: scrolling in SAMPLE PLAYER's slice view now wraps at the begin/end of the sample
  • ENHANCED: added hard sync to SINE OSC unit
  • ENHANCED: you can now undo the following actions: clear chain, delete unit
  • ENHANCED: now in some units, if you can focus press a parameter to get its contextual view
  • ENHANCED: keyword filtering added to the unit selection screen
  • ENHANCED: 24 quicksave slots
  • ENHANCED: OUT1-4 can be routed to chain inputs
  • ENHANCED: units can be renamed
  • QUESTIONABLE TWEAK: replaced SAMPLE PLAYER's linear fade with a cosine fade
  • NEW UNIT: Custom Unit (encapsulate a chain of units)

Patch 2

  • FIXED: firmware updater crashes when pressing the update button

Patch 3 (The Neil Parfitt patch) 

  • FIXED: focus pressing a control caused it to lose focus
  • FIXED: fixed some visual issues with fonts (0, r, and t)
  • FIXED: sub-chain edits were not being reflected in the parent parameter's miniscope
  • FIXED: local sources are placed first, in the source selection screen
  • FIXED: accidentally, left out the SINE unit's level parameter from UI
  • ENHANCED: GUI animation settings added (slow, normal, fast, disabled)
  • ENHANCED: Custom Unit names are randomly generated
  • ENHANCED: Custom Unit control editor, pressing S1 will cycle through options
  • ENHANCED: Unit presets that are saved in ER-301/sc/presets/units/chooser now show up in the unit selection screen.

Patch 4 (The sunshinelover patch) 

  • FIXED: Characters were being inserted on button release (should be on the press) in the keyboard screen.
  • FIXED: "Prompt" setting for reloading quicksaves on boot was not working.
  • FIXED: Unit names were not restoring properly when loading presets due to incorrect saving logic.
  • FIXED: Crash when inserting unit and front SD card is not mounted.
  • FIXED: Suggested filenames are no longer erased when typing (press SHIFT+HOME to clear the text box).

Patch 5

  • FIXED: Crash in sample slice view.
  • FIXED: Disabled wrapping around in slice view.
  • FIXED: Cursor not showing in channel setup.
  • ENHANCED: Focus press unit header to switch between unit's control view and menu view.
  • ENHANCED: Normal press unit header to left justify the unit.
  • ENHANCED: Unit bypass now implemented.

Patch 6

  • FIXED: Crash when CPU is overloaded.
  • FIXED: Removed zombie sub-screens in admin menu.
  • FIXED: 6-track recorder is back with cleaner UI (and internals).
  • ENHANCED: 6-track recorder now has presets and it's state is saved with quicksaves.
  • ENHANCED: file/folder dialogs have been consolidated and improved.
  • ENHANCED: At anytime, SHIFT + channel buttons 1-4 will mute/unmute the corresponding chain.
  • NEW UNIT: I've been stress testing the firmware with this CV-able STRESS unit.

Patch 7

  • FIXED: Mono version of STRESS unit crashed on load.
  • FIXED: Garbage values in frequency measurement display over gate control in the CUSTOM unit.

Patch 8

  • FIXED: limited pitch modulation range on CUSTOM unit
  • FIXED: In Chain Preset Saving, the button release from pressing "Save" was inadvertently activating the "New Folder" option on the next screen.

Patch 9

  • FIXED: creating a new folder while saving chain/unit presets caused .lua to be appended to the folder name.

Patch 10

  • FIXED: Got rid of the intermediate "switch" state on the units.
  • FIXED: 6-track recorder UI behaved weirdly when recording buffers overflowed.
  • ENHANCED: added context-sensitive hints to the 6-track recorder setup screen.
  • ENHANCED: audio is faded out/in whenever you mute/unmute a chain
  • ENHANCED: chain is now auto-muted before you clear or link/unlink channels

Patch 11

  • FIXED: freeze when automatically restoring (w/o prompt) the last quicksave on boot.
  • FIXED: incorrect "failed to load quicksave" error message when loading quicksaves made before patch 6.

Patch 12

  • FIXED: Sometimes unit subscreen contents are blank after returning from a menu action.
  • FIXED: When loading a quicksave, 6-track configuration is only loaded if not already recording.
  • FIXED: Track-and-Hold unit was not tracking when used in a mono chain.
  • FIXED: Unit bypass menu item was not working when the unit was collapsed.
  • ENHANCED: Changed default unit settings for MIXER gain and PLAYER speed.
  • ENHANCED: ADSR parameters have been extended out to 10sec.

Patch 13

  • FIXED: LOOPER's fade on reset functionality was missing.
  • FIXED: Sequential channel bleed on the G inputs.

Patch 14

  • FIXED: SHIFT+HOME (ZERO) now uses the press event rather than the release event.
  • FIXED: LOOPER preset will now restore buffer characteristics (max loop length and # of channels).
  • FIXED: Negative start parameter values in the LOOPER unit didn't wrap around.
  • FIXED: SAMPLE PLAYER would not stop at previous slice when speed is negative. 
  • ENHANCED: LOOPER start parameter has been changed to proportion of maximum loop length (was seconds).
  • ENHANCED: Changed default frequency settings for SIN OSC and LADDER FILTER.

Patch 15

  • FIXED: PLAYER gets stuck if the active slice is at the exact beginning or exact ending of a sample.

v0.1.5p23 (Bleeding Edge) 96kHz or 48kHz

FIXED: overflow in feedback path of LADDER FILTER unit
FIXED: tune(v/oct) subchain of SAMPLE PLAYER was accidentally disabled
FIXED: deleting active slice did not deactivate it
FIXED: reduced SINE OSC unit output amplitude
FIXED: lower frequency range for SINE OSC unit
FIXED: frequency faders are now log-scaled

- FIXED: occasional crash when quicksaving a large number of units
- FIXED: can't delete sample when its status pending
- FIXED: pressing shift in sample pool brings up obsolete screen
- STOPGAP: mute DAC on crash
- STOPGAP: units are presented in a fixed order in the (currently primitive) unit insert menu
- ENHANCED: replaced tanh with cubic mode in LIMITER unit
- ENHANCED: gains are modulatable in EQ3 unit (but still needs more attention)
- NEW UNIT: Sine Oscillator (exponential FM only for now)
- NEW UNIT: Ladder Filter (4-pole LPF with non-linearity in feedback)

- fixed crash when playing a slice in reverse at a speed above x2.5
- removed display of logs during loading/saving of presets
- added popup messages to many situations
- fixed cursor ending up off screen after loading chain preset
- crash using quicksave screen while cpu load screen (admin+scope) is showing
- increased button debounce time to 100ms

- support for 8-bit and 32-bit integer WAV files added
- capped CPU usage for PLAYER unit when playing at higher speeds without reducing fidelity

bug fixes
- crash when ejecting card that is in use (i.e. loading samples)
- occasional crash when deleting slices in player unit
- scrolling freaks out when chain is shorter than display
- buttons obscured by large amplitude waveforms
- parameter scopes don't update their targets when there is a change in the subchain.
- MIXER meters don't update their targets when there is a change.
- made preset loading more robust against file corruption

- save state of engage/punch buttons in presets

bug fixes
- increased debounce time from 1ms to 50ms

bug fixes
- cleaned up some inconsistencies in the sample pool UI: better error messages and proper clearing of multi-selections.
- added extended WAVE file format support (some converters write in this format)
- added broadcast WAVE format (BWF) support (some portable recorders write in this format)

bug fixes
- default load path for unit preset did not use unit type
- fixed "crash" when aggressively modulating sliced sample playback speed
- clearing a chain now clears the input assignment

ui enhancements
- non-modulatable faders now have scopes that monitor unit output

- renamed mix parameter to dub
- added wet/dry parameter to facilitate input monitoring

- added pre and post gain level meters

- added new parameters: pre-scale, # of levels, post-scale

clocked delay
- time factor parameter has been substituted with 2 modulatable parameters: numerator and divisor

new units
- sample and hold
- track and hold
- rational vca
- period meter

new settings
- enable dev mode (please ignore this for now, it's just for me)

bug fixes
- empty chains now pass audio

new settings
- quicksave restore on start-up: yes, no, prompt
- set snap to zero-crossing commands

  • Display a message (instead of crashing) when you try to load a non-preset file from the preset load screen.
  • Removed the bypass button because bypassing is not implemented yet.
  • Some missing arrows fixed in the sub display screens.
  • CPU load now only shows the load for critical threads.

The journey starts here.