eurorack

Mutable Instruments - Marbles: Truchets

A reimagining of Mutable Instruments Grids drum pattern generator, now living inside Marbles. Truchets is built on Marbles 1.3, it adds a new T-side mode and new X-side features while keeping all original Marbles functionality intact.


For the latest update file go to the release page.
When you need instructions on how to update your marbles go to the original manual.


Contents

  1. Button Behavior
  2. Marbles Enhancements
  3. Activating Grids Mode
  4. Outputs
  5. Standard Controls
  6. X Shift Layer - Knobs
  7. X Shift Layer - Buttons
  8. Advanced Settings Layer
  9. Patching Ideas
  10. Credits


Button Behavior

T Mode and X Mode buttons use tap and long-press to navigate between modes:

Press Duration Behavior
Short tap (< 275ms) Cycle within current bank
Medium press (275ms–2s) Ignored (prevents accidental changes)
Long press (≥ 2s) Switch between banks (no blink/blink)


Marbles Enhancements

These features extend the standard Marbles functionality and are available outside of Grids mode.

X Modes

The X Mode button now has 5 modes split into two banks:

Bank LED State Name
Basic Solid Green Identical
Basic Solid Orange Bump
Basic Solid Red Tilt
Alternative Blinking Green Round Robin
Alternative Blinking Orange Envelope

Short tap cycles within the current bank. Long press switches between banks.


Round Robin (Blinking green)

Cycles through X1/X2/X3 outputs one at a time. Each clock pulse advances to the next channel. When clock is not patched the clocking signal comes from T2.

In normal green mode, all three X outputs share the same random sequence in a shift-register style — X1 gets the newest value, X2 gets the previous, and X3 the one before that. In round robin, only one output updates per clock tick while the other two hold their last value, cycling X1 → X2 → X3.


Envelope (Blinking orange)

Generates attack-decay envelopes on X outputs triggered by t1t2t3 or clock input.

Control Function
Spread Random envelope time distribution
Bias Envelope length
Steps Attack/decay ratio

X Range changes retrigger behavior:

LED State Retrigger Mode
Green (narrow) Hard reset on every trigger
Orange (positive) Only retrigger after attack phase (Serge-style)
Red (full) Only retrigger after envelope completes (legato)

With external clock, envelopes trigger round-robin style (one channel per trigger). With internal clock, all channels trigger independently.


X Ext Modes

X Ext cycles through 3 modes:

LED State Mode Function
Off Normal Standard behavior
Solid Green External Original external input behavior
Blinking Green Transpose Spread CV input becomes V/Oct transposition

In Transpose mode, the Spread CV input applies a pitch offset to all three X outputs. The input uses a V/Oct correction curve for tracking accuracy. While the hardware is not made for it this curve tries to fix that.


Explicit Reset

Press T Mode + X Mode to cycle through 4 states:

State T Section Reset X Section Reset
Off Disabled Disabled
1 Enabled (T Jitter input) Disabled
2 Disabled Enabled (X Steps input)
3 Enabled Enabled

After toggling, T Deja Vu and X Deja Vu LEDs flash for 1 second to indicate which sections are active.


Activating Grids Mode

Long press T Mode while on drum mode (solid red) to enter Grids mode (blinking red).

To exit, long press T Mode without changing anything in the advanced layer.

Grids mode outputs

Output Function
T1 Kick trigger
T2 Hi-hat trigger
T3 Snare trigger
Y Accent output
X1/X2/X3 Random voltages

X1/X2/X3 are following the standard Marbles behaviour. All X controls still function like the original firmware. X2 follows hihat pattern instead of master tempo source.


Standard Controls

Density Knobs

Knob Controls
Bias (T) Kick density
Rate Hi-hat density
Jitter Snare density

All three respond to CV input.

Deja Vu (T Side)

The Deja Vu section controls pattern looping:

Deja Vu Amount Behavior

Direction Effect
Left Chance to shift loop start point +1 step each cycle
Noon Neutral
Right Chance for density drift on steps (clears when unlocked)

When the knob is fully left the chance to shift is 100%.

Density drift is inspired by the Chaos parameter. The key differences: Chaos always adds hits (fills), while Density drift can both add and remove hits. Chaos is always random (even when the loop is locked), while Density drift locks with Deja Vu. Chaos re-rolls once per loop cycle, while Density drift is applied per step.


X Shift Layer - Knobs

Hold X Mode and turn knobs to access hidden parameters.

All shift layer parameters have a neutral position at noon (12 o’clock), meaning they have no effect on the sound until you turn them.

Groove Offset (x Bias)

Position Effect
Far left Kick +3 steps late
Center left Kick +1 and +2 steps late
Left Kick micro-timing late (up to 50%)
Noon Neutral
Right Snare micro-timing late (up to 50%)
Center right Snare +1 and +2 steps late
Far right Snare +3 steps late

Rate (Rate)

The same Rate/tempo control from the standard Marbles interface, moved here to free up the knob for hi-hat density.

Swing (Jitter)

Position Effect
Left Classic swing
Noon Neutral
Right Tresillo swing

Both swings go to 50% max.

Map X & Map Y (Steps & x Bias)

Change the pattern coordinates on the current bank.

Original Grids manual

Chaos (Spread)

Position Effect
Left Random tempo jitter (humanize)
Noon Neutral
Right Density Chaos (ghost notes / fills)

The left side of the chaos knob uses the normal Jitter logic from the other modes.

Accent Control (Deja vu)

Position Effect
Far left Kick accent only
Left Hi-hat accent only
Center-left Snare accent only
Noon All accents combined (original behaviour)
Right to far right All accents combined, lowering threshold

192 is the original grids threshold for an accent and is used on the left to noon side of the knob.

Lowering threshold creates more gates. If accent control is fully to the right an accent will always be fired when any of the outputs are firing.

Accent Variation (Length)

Position Effect
Left Random voltage window
Noon Neutral (5V gates)
Right Velocity-sensitive gates (stronger accents = higher voltage)

Both sides start as fixed 5V gates near noon. Turning the knob further from center widens the voltage window, reaching the full 0V–5V range at the extremes.

The random voltages are locked with the Deja vu function.


X Shift Layer - Buttons

Hold X Mode and press buttons to access CV routing and bank select.

Pattern Banks

Hold X Mode + tap T Mode to cycle through pattern banks:

LED State Bank
Solid Green OG Grids
Solid Orange Electronic
Solid Red Breakbeat
Blinking Green OG Grids (no interpolation)
Blinking Orange Electronic (no interpolation)
Blinking Red Breakbeat (no interpolation)

Interpolation vs No Interpolation: With interpolation (solid LED), patterns morph smoothly between the 25 positions in the 5x5 grid as you adjust Map X/Y (Same as the original Grids). Without interpolation (blinking LED), Map X/Y snap to the nearest of the 25 grid positions — no morphing, just the raw patterns.

CV Swap Routing

Hold X Mode + Press LED State CV Source
T Range Off No CV
  Green Steps CV → Map X
  Blinking Bias (T) CV → Map X
X Ext Off No CV
  Green Spread CV → Chaos
  Blinking Rate CV → Chaos
X Range Off No CV
  Green Bias (X) CV → Map Y
  Blinking Jitter CV → Map Y

The routing follows a left-to-right logic across the panel. The buttons (center) map to the shift layer knobs (right side): one press assigns the CV input next to that knob (green), a second press mirrors it to the corresponding CV input on the left side of the module (blinking).

Deja Vu CV Swap

Hold X Mode + Press LED State Function
T Deja Vu Off Normal behavior
  Green Deja Vu CV gates T-side lock
X Deja Vu Off Normal behavior
  Green Deja Vu CV gates X-side lock

When enabled, a gate signal (+2.5V) on the Deja Vu CV input flips the lock state.


Advanced Settings Layer

Hold T Mode and press buttons to toggle advanced settings.

Hold T Mode + Press Setting Off (default) On (LED lit)
T Deja Vu Loop playhead Shared playhead Independent playhead
X Deja Vu Loop start Dynamic (from current step) Always from beat 1
T Range Read mode Normal Henri
X Ext Accent hang Normal gates Hanging accents
X Range Knob swap Normal knob locations Knobs swapped
X Mode Explicit reset Off 4 states (see Explicit Reset)

Setting Descriptions

Independent Loop Playhead (T Deja Vu)

When on, the loop has its own playhead separate from the main pattern. When you unlock, playback stays in sync with where the pattern would have been.

Loop from Beat 1 (X Deja Vu)

When on, loops always start from step 1 of the pattern instead of the step where you activated the loop.

Henri Mode (T Range)

Switches pattern reading between Normal (original Grids algorithm) and Henri (alternate reading from Grids4Live Max plugin). Henri mode produces different rhythmic relationships between kick, snare, and hi-hat.

Accent Hang (X Ext)

When on AND an accent variation is active, accents will sustain until the next accent fires.

This turns accent into a sample and hold output driven by accent and the current accent variation.

Knob Swap (X Range)

When on, the Marbles knobs (Steps, Bias, Spread) directly control Grids coordinates (Map X, Map Y, Chaos). Marbles X parameters use stored alternate values. When off (default), Marbles knobs control Marbles X parameters and Grids coordinates comes from the shift layer.

When toggling, current knob positions are captured to prevent parameter jumps.

Knob swap is independent of CV swap. CV swap routes CV inputs to Grids coordinates, while knob swap changes which parameters the physical knobs control. Both can be used at the same time.

Explicit Reset (X Mode)

Now supports 4 independent states for T and X sections. See Explicit Reset for full details.

Gate length control (t Bias & Jitter)

While Holding T Mode the gate configuration parameters are still accessible.

Marbles manual about gate configuration


Patching ideas


Credits