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 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
- Activating Grids Mode
- Outputs
- Standard Controls
- X Shift Layer - Knobs
- X Shift Layer - Buttons
- Advanced Settings Layer
- Patching Ideas
- Credits
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.
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:
- T Deja Vu Button: Tap to toggle loop lock on/off
- Deja Vu Length: Sets loop length (when locked)
- Deja Vu Amount: Controls loop behavior (see below)
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.
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 Model 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 Model and press buttons to toggle advanced settings.
| Hold T Model + Press | Setting | Off (default) | On (LED lit) |
|---|---|---|---|
| T Range | Read mode | Normal | Henri |
| X Ext | Accent hang | Normal gates | Hanging accents |
| T Deja Vu | Loop playhead | Shared playhead | Independent playhead |
| X Deja Vu | Loop start | Dynamic (from current step) | Always from beat 1 |
| X Mode | Explicit reset | Off | On |
Setting Descriptions
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.
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.
Explicit Reset (X Mode)
Original Marbles 1.3 setting. When enabled, reset input resets the pattern to step 1 or to the first step of the loop window when looped.
Gate length control (t Bias & Jitter)
While Holding T Model the gate configuration parameters are still accessible.
Patching ideas
- Grids mode can still feel really random by turning Chaos fully clockwise or counter clockwise and having a high swing value.
- Use a small amount of Jitter for a humanized feel.
- Turning on Henri mode can give you a B side of a beat. Turning it on and off can give some nice breaks.
- Self patching Marbles X side to any grid parameter can give great results.
- Having a high spread and steps on the X side can give random gate outputs driven by the Grids gate generation. Essentially creating 7 gate outputs.
- Having a offset module patched to Map/Chaos cv in can give you direct control over these parameters without using the shift layer. Think of Stages, Shades or Blinds
Credits
- Original Marbles & Grids firmware by Émilie Gillet (Mutable Instruments)
- This very handy grids pattern website by Michael Forrest
- VCV Rack Topograph for all the A/B Testing by Dale Johnson
- Henri mode based on Grids4Live by Henri David