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Firmware Release Notes

For instructions on how to upgrade your ER-101 firmware: ER-101 Programmer Application.
ER-102 Users:  You only need to update your ER-101 firmware when a release is marked with an asterisk (*). 

Pending Bugs
  • None (yet)
Pending Feature Requests
  • Ability to set root note (rt) for chromatic display.
  • operation to extrapolate an entire voltage table from a smaller set of voltages

  • Bug Fix: Random MATH operator had a minimum output value of 1.

  • Bug Fix: CV outputs overflow when clock divider > 1 and SMOOTH is enabled.
  • Bug Fix: While editing a MATH transform, the focus LED (orange) gets turned off when you push the RESET button or receive a gate on the RESET input.
  • Feature enhancment: Show nP (number of pulses) when focus pressing the PATTERN or TRACK.

  • Bug Fix: Problem controlling the orange LEDs when using the ER-101 with the ER-102.

  • Feature enhancment: Flash actual loop step number when setting loop points with PATTERN focused.
  • Bug fix: Copying across snapshots in HOLD MODE has bugs.
  • Bug fix: Math transform gets applied when pinning the math screen.
  • ER-102 users: Do not use this firmware for your ER-101, it has problems controlling the orange LEDs.

  • Fixed version discrepancies in the manual.
  • Feature enhancement: On start-up, load last saved or *loaded* snapshot.
  • Feature enhancement: Pattern-based looping (press LOOP buttons while PATTERN is focused to quickly loop patterns).
  • Feature enhancement: Blank snapshot (displayed as '--') can be loaded to start a fresh snapshot.
  • Bug fix: Crash if you turn knob during startup splash screen.
  • Feature enhancement: Hold INSERT button, select SPLT with the RIGHT knob to split steps or patterns.
  • Feature enhancement: Added help indicators to the track config screen.

  • Bug fix: clock display was overwriting the MATH overlay
Known Issues
  • During startup, ER-101 might display the message "14 bit" even though you have an older 12-bit device.  This has no impact on the operation of your module.

  • Improved stability of the ER-101/102 communciation.
  • Lots of little user interface improvements.
  • Simultaneous Clock Divide and Multiply 

    - now you can divide the clock as well as multiply the clock 
    - generate clocks that just multiply or just divide cannot achieve, such as 2/3 or 5/7 of the original clock 
    - "focus press" the TRACK button to get to the track configuration screen and adjust the divider and multiplier amounts 
    - NOTE! The multiply amount has been moved to the STEP display and the divide amount is shown in the DURATION display (just like a ratio 2:3, 1:2, 13:19 and so on) 

  • The main purpose of this release is to add support for the ER-102 Sequencer Controller.
  • Bug fix: GATE output is set low when the corresponding track is deleted.
  • Bug fix: Suppress voltage display when showing track configuration.
  • Bug fix: BLUE and 22JT voltage tables were incorrectly swapped.
  • Bug fix: Reset all timing counters to zero when PAUSE button is pushed.  
  • Feature enhancement: added qt (quantize) operation to the MATH transform.


  • Bug fix: more robust synchronization with external step sequencers via RESET (i.e. handle reset pulses that arrive soon before or after the clock edge)
  • Bug fix: pausing the sequencer no longer affects the ER-101's estimate of clock period that is used in the clock multiplication algorithm.
  • Plus some internal optimizations in preparation for the ER-102 Sequencer Controller.


Track Configuration

Once the TRACK display is focused, you can press and hold the TRACK focus button to see the TRACK configuration for the current track. There are 4 configuration items shown in the CV-A, CV-B, DURATION and GATE windows:

CV-A: note display (Nt) vs number display (Nr) for table A
CV-B: note display (Nt) vs number display (Nr) for table B
DURATION: clock multiplier (1x, 12x, 24x, 48x, or 96x)
GATE: gate mode (Gt) or trigger mode (Tr)

Just press the focus button next to each configuration item to cycle through the values.

Note Display

When note display is enabled for a particular track and table then the VOLTAGE window will show:

{octave:0-8}.{note:A-G}.{percent of a whole tone:0-99}

Here are some examples
C2 --> 2.C.00 
A#3 --> 3.A.50 
Bb5 --> 5.A.50 
G(half-sharp)4 --> 4.G.25 
G(sharp-and-a-half)4 --> 4.G.75 

Repeatedly pressing the VOLTAGE focus button (or turning the RIGHT knob while holding this button) cycles through 3 levels of granularity:

Fine: +/-2mV or +/-2 cents or +/-1% of wholetone
Coarse+/-100mV or next/prev chromatic note
Super Coarse: +/-1V or +/-1 octave

The last used setting is remembered and saved with your snapshots.

- Some notes in the 12ET (chromatic) reference table were tweaked up or down by a few cents to make the note display more consistent (more specifically, I switched from round-down to round-to-nearest). This means that old snapshots from previous firmware versions will have some notes displayed oddly (i.e. G#3 --> 3.G.49 instead of 3.G.50, etc.). The reason for this is that while the resolution of the note display is +/-2 cents, the output resolution of the ER-101 is only +/-2.4 cents, so there is a small bit of nudging required here and there.

Trigger Mode

Once you have enabled triggers for a particular track (as above procedure) then all gates for this track become triggers with a duration equal to the steps's GATE value multiplied by 0.1ms. So if a particular step has GATE=10 then the trigger will last 10 x 0.1ms = 1ms. Particularly when pinging a filter, different trigger lengths will sound different. The range for triggers is 0.1ms to 9.9ms in 0.1ms increments.

-If you enable note repeat (ratchet) while in trigger mode, then the trigger length defaults to 0.5ms and the GATE value now determines how many times the trigger will fire during the duration of the step. Notice, this is slightly different from gate mode's note repeat.
-While in trigger mode, smoothing duration defaults to 50% of the step duration.

Clock Multiplication

This one is pretty simple. Once you enable clock multplication for a given track, then that track will just behave as if it was given a faster clock. For example, if you configure a track's clock multiplier to 48 then for each single pulse of the global clock, the track in question will receive 48 pulses and thus run 48 times faster. In this track, a step with DURATION=48 will last for exactly one single cycle of the global clock. 

A multiplied track will go out of sync with other tracks if you change the clock multiplier or wiggle the global clock frequency while the sequencer is playing. In these cases, just send the ER-101 a RESET to put things back in to sync. This is typical behavior for clock multiplication modules.

MATH Transform per TRACK

Each track now has its own transform via the MATH button, rather than one global transform shared by all tracks.

Last Saved Snapshot

On power up, the ER-101 will load the last saved snapshot.

User Reference Tables

There are now 8 user reference tables (USr1 to USr8) that can be used to store your own customized voltage tables. They are accessed and copied the same way as other reference tables. You alter the contents of a user reference table by copying a track's voltage table (A or B) and pasting it onto the desired user table. These tables are not included in the snapshots and are not affected by loading of a new snapshot. These user tables are truly just like another reference table and are always available, unless overwritten by a firmware upgrade.


  • Feature Enhancement: Transferring pulses between adjacent steps. You can now adjust a step boundary (thus keeping the pattern/track duration unchanged)  by just holding down the DURATION button and using the RIGHT knob to steal pulses from or give pulses to the next step (LOOP points are considered). While you are transferring pulses, the VOLTAGE display will temporarily show explicitly how the duration of the current and next step are changing. This method is especially useful for making rhythmic changes to your sequence without losing sync with other material.
  • Feature Enhancement: Note repeat (also known as ratcheting) for each step. If you press the GATE button while the GATE parameter is focused then the continuous trigger (i.e. ratchet) mode is toggled for that current step (indicated by the 2 dots lighting up in the GATE display). Ratcheting means that the gate will repeatedly fire for the duration of the step. The value of the GATE parameter still indicates the length of the gate signal. The step DURATION and GATE together determine how many times the gate output will trigger. For example, if the step DURATION is 16 and the GATE is 4 pulses (on the display shown as '0.4.') then the gate will go high for 4 pulses, low for 4 pulses, high again for 4 pulses and then low again for 4 pulses.
  • Feature Enhancement: In addition to the focus buttons, you can now use the LEFT knob to change the transform when setting a MATH operation.
  • Bug fixOn some power supplies the ER-101 might leak a 366Hz tone on to the power rails. The reason was that the PWM frequency for the orange LEDs was mistakenly set to audio range (366Hz) and below the cutoff frequency of the ER-101's power filter. The fix was to set the PWM frequency to 200kHz, well above the cutoff frequency on the power filter for the ER-101.
  • Bug fix: The ER-101 might freeze when you set LOOP points in a sequence with all steps having zero DURATION. This has been fixed now.