Beads - firmware update, release candidate

Thanks to everyone for the massive amount of feedback I have received after the launch of this module! It certainly got used more in these past two months, than during the final year of polishing and testing that lead to its release.

Note: if your module was sold to you after May 2021, it already contains an up-to-date firmware!

Audio quality

  • A CPU overload issue causing crackles on the left channel in 48kHz/stereo mode with some specific combinations of SIZE and DENSITY has been fixed, through several code optimizations having no negative impact on the module’s functionality.
  • When recording restarts after FREEZE is disabled, the duration of the crossfade between the tail of the buffer and the incoming audio has been increased, thus reducing vastly the risk of clicks.
  • When the module operates as a delay, a smooth transition zone has been added between each of the multiplication factors selected by the TIME setting. This prevents the glitches that occurred when TIME was modulated and the play-head abruptly jumped from one position to another.
  • When the module operates as an externally clocked delay, and when the clock rate changes (abruptly, or because of swing or jitter), a crossfade is applied between the old and new delay time, eliminating clicks.
  • When the module plays slices (delay mode + FREEZE enabled), it waits for the completion of the currently playing slice before sampling the TIME parameter and deciding which slice to play next. Again, this prevents clicks when TIME is modulated.
  • The modulation of the secondary delay tap (DENSITY past 12 o’clock, free-running) has been tamed to avoid noticeable warbling or pitch-shifting effects.
  • A fade-out and fade-in is applied during the transition between granular and delay mode.
  • The algorithm responsible for preventively fading out grains to make room for new ones behaves more cautiously. This reduces, by a negligible amount, the overall thickness of the grain cloud (since at a given time, several grains will enter their release stage earlier than scheduled), but reduces the risk of grains being abruptly cut when “grain-stealing” occurs.
  • The power consumption of the module exhibits less bursty patterns, eliminating the whine observed with some PSUs.
  • Linear interpolation is applied to the frequency parameter when generating the dry (continuous) signal in granular wavetable mode.
  • The filters used for band-limited wavetable synthesis have been improved, eliminating the amplitude drop observed for the highest notes.


  • The response curve of the attenurandomizers has been slightly adjusted, with a smaller virtual notch at 12 o’clock, and a more progressive transition between small and extreme values. Graphing Calculator
  • The response curve of the SIZE control has been adjusted. The deadband in the backward/forward transition zone at 10:30 is smaller, the reclaimed space giving access to even shorter grains.
  • The interaction between the PITCH knob and its attenurandomizer has been adjusted. In particular, when the attenurandomizer is fully CW or CCW without any CV in, the main knob still provides an additional transposition control.
  • When turned CCW, the reverb amount knob no longer eliminates the wet signal, but instead, stops sending any signal to the reverb. This allows the tail of the reverb to fade out more gracefully when the knob is turned towards its minimum position.
  • The root note of the wavetable oscillator has been transposed down by one octave.
  • The software low-pass filter on the PITCH CV input has been disabled, to shorten its response time. On the hardware side, the 8x averaging performed by the MCU provides enough denoising anyway.
  • When the grains are externally triggered and the DENSITY knob is repurposed as a probability control (from 12 o’clock to fully CW), a quadratic response is used for the probability value. It makes it easier to get sparse grains, even with a fast clock.
  • Less hysteresis is applied on CVs controlling quantized parameters (such as the selected wavetable, or the selected slice). Sequencing these parameters yields more predictable results, since the risk of sending a voltage in the transition zone is reduced.
  • The range of the feedback control has been increased by 30%.

New features

  • Four FM wavetables have been added, with modulator:carrier ratios of 1:2, 1/2:1, 3:1, and 8:1.
  • Assign + FREEZE now enables or disables the auto-saving of the buffer. The current setting is indicated for a short amount of time by the brightness of the FREEZE button (bright = on, dark = off).
  • The visual indication that the frozen buffer is being backed up (fast blinking of the FREEZE button) has been made more subtle: instead, the FREEZE button is only dimmed while this process takes place.
  • When the module operates in the delay zone (SIZE turned fully CW), the SIZE attenurandomizer is repurposed as a delay bandwidth control, from dark to full to thin. This parameter can also be further modulated by the SIZE CV input.
  • The audio quality LED fades out every time the recording head crosses over the last point at which FREEZE has been disabled. This gives a visual representation of how much material fits in the buffer.
  • The audio quality LED temporarily changes color when the input gain is being manually adjusted.
  • When the input gain is manually set, the flavor of the clipping applied to the input signal, when it saturates, varies according to the quality setting. The two digital modes incur no distortion when the signal is within limits, but past that threshold, hard-clipping is applied. The two tape modes apply soft-clipping, which may gently add harmonics to the signal even when it is within limits.

The update file is available here: (1.7 MB)

Note: if your module was sold to you after May 2021, it already contains an up-to-date firmware!

The update procedure is explained at the end of the manual.


Wonderful. Thank you!

This is great Émilie, can’t wait to try it!

Happy ! Thank you. :blush:

Nice additions as well as the bug fixes! :sunglasses:

One word : THANKS ! :pray:
:clap: :clap: :clap: :blush:

Now, Beads is playing Silver Apples of the Moon by itself!


Wow and thank you.

“Four FM wavetables have been added, with modulator/carrier ratios of 1:2, 1/2:1, 3:1, and 8:1.”

i’m sorry but 1:2 and 1/2:1 aren’t the same ratio?!?!

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This is not the same thing because we are talking about wavetables made of single cycle waveforms, not about a continuously running FM algorithm.

When the ratio is 1/2:1, the modulator doesn’t complete its full cycle before the waveform is repeated. When the ratio is 1:2, the modulator can complete its full cycle.

Another way to look at it is that the 1/2:1 version is a hard-synced (with a forced phase reset) version of the 1:2 version.

Or that the 1/2:1 version employs a half-sine instead of a full one as a modulator signal.


[chef’s kiss]


Amazing, thank you for the hard work!

Many thanks for this great and hard work!

Oh my goodness.

It’s been said many times before but deserves repeating. @pichenettes your attention to detail and dedication to support is absolutely astounding. Yes some are bug fixes but the little details in these fixes that result in improvements (smaller grain sizes etc) plus the new stuff, as @erstlaub puts it, are [chef’s kiss].


Wow, now that’s not just dotting the i’s and crossing the t’s, that’s rebuilding the whole pen :slight_smile:
Do we need to re-calibrate the unit after the firmware upgrade?

No! Never with Mutable Instruments’ official releases!


Thanks! Excited to try the new firmware later today.

Wonderful update!

I like to do gated reverb shots, unfortunately by controlling the send instead of the wet you get the tail which softens this effect. For the rest of applications I agree is better though.

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Thank you for this! :grinning:

I can confirm that the issue I had when posting Beads constant high pitched noise on outputs is now completely gone! No more high frequency spikes, in fact no more noise at all.

Also the bonus features and updates are very nice indeed! I especially like the reverb tail naturally decaying when quickly turning the reverb knob CCW.

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Happy dance! I’m really glad that the software fix worked, because the hardware fix would have required something like 1000µF of capacitors. :rofl: The back of the board would have been littered with tiny metal cans…