Eurorack Reference / modules /4ms/ensemble-oscillator audit site v0.1 — milestone 3
4ms/ensemble-oscillator

Ensemble Oscillator

4ms

A polyphonic voice of sixteen sine-based oscillators combining additive, FM, phase-distortion and wavefolding synthesis techniques, with oscillators quantized to user-selectable scales or harmonic series for exploring the boundary between chords and rich evolving textures.615

Capabilities 4

Polyphonic Oscillatorpolyphonic-oscillator
16 sine-based oscillators with FM, phase distortion, and wavefolding; oscillators quantized to user-selectable scales615
Quantizerquantizer
615
Wavefolderwavefolder
Three Warp algorithms: analog-style fold (up to 6 folds), Chebyshev polynomial (up to 16th order), and linear segment (8 shapes)615
Waveshaper / Wavefolderwaveshaper
615

Jacks 12 — 10 in / 2 out

NameSignalVoltageDescription
Inputs (10)
Balancecv-5V to 5V615
Cross FMcv-5V to 5V615
FreezetriggerTrigger input that freezes/unfreezes oscillator frequencies. Toggles freeze state each time a trigger is received.615
LearngateGate/trigger input used in Learn mode to add notes to a scale. Also used as the audio input for firmware updates. Outside of Learn mode, any gates received are ignored.615
Pitchcv-2V to 6V1V/oct input that transposes all oscillators after quantization. Also used in Learn mode to input note pitches. Voltages -2V to +6V.615
Rootcv-2V to 6V1V/oct CV input controlling the pitch of the lowest (root) oscillator before quantization. Voltages between -2V and +6V (8 octave range).615
Scalecv-5V to 5VCV input selecting scale within the current group. Negative voltages select lower-numbered scales, positive select higher-numbered scales, relative to knob position.615
Spreadcv-5V to 5VCV input with linear response controlling oscillator spread. Negative voltages reduce spread, positive voltages increase spread.615
Twistcv-5V to 5V615
Warpcv-5V to 5V615
Outputs (2)
Out AaudioAudio output. In mono mode (Out B unpatched), carries the sum of all oscillators. In stereo mode, carries panned oscillators per the Stereo Mode setting.615
Out BaudioSecond audio output for stereo operation. When patched, oscillators are panned between Out A and Out B per the Stereo Mode setting.615

Parameters 19

NameTypeRangeBehavior
# Oscillatorsknob1 – 16Shift function (Freeze + Spread): sets the number of active oscillators from 1 to 16. Default is 16. Reducing count decreases density and increases perceived loudness. Disabled frozen oscillators lose their frozen frequency.615
BalanceknobControls balance/mix between oscillators. Also accesses Crossfading shift function when Freeze is held.615
Cross FMknobControls the amount of FM between oscillators. At minimum there is no modulation; turning up creates complex harmonics. The algorithm (which oscillators modulate which) is set by the Cross FM switch.615
Cross FM SwitchswitchSelects FM algorithm. Up: root oscillator modulates all others. All: each oscillator modulates the next higher one. Down: highest oscillator modulates all others.615
CrossfadingknobShift function (Freeze + Balance): controls steepness of crossfading between scale notes. Fully CCW disables crossfading (oscillators snap to nearest note). Center applies small crossfading (default). Fully CW applies maximum crossfading (always blends two nearest notes).615
DetuneknobAdjusts detuning of oscillators after quantization. Root oscillator is not detuned; odd-numbered oscillators are detuned upward, even-numbered downward. Small amounts create lush stereo fields; larger amounts create beat frequencies and dissonance.615
FreezebuttonFreezes/unfreezes a subset of oscillators. Frozen oscillators do not respond to pitch controls but still respond to Twist, Warp, Cross FM, and Balance. Hold while turning knobs to access Shift features (#Oscillators, Crossfading, Stereo Mode, Freeze Mode).615
Freeze ModeknobShift function (Freeze + Twist): selects which subset of oscillators is frozen. Three options: freeze only the root oscillator (highest setting), freeze the bottom half (e.g. 1-8 of 16), or freeze odd-numbered oscillators (lowest setting).615
LearnbuttonEnters/exits Learn mode for creating and saving custom scales. Flashes green on successful save. Hold for 4 seconds to restore the selected factory scale. Also used to enter/confirm steps during calibration.615
PitchknobTransposes all oscillators after quantization, preserving intervals. Used to tune to other equipment or provide pitch-sweep effects. Holding Shift while turning fine-tunes the pitch. Fine-tune amount is saved across power cycles.615
RootknobControls the pitch of the lowest (root) oscillator before quantization. Adjusting causes oscillators to crossfade between notes in the selected scale. When used with Pitch, the range exceeds human hearing from about 1Hz to over 20kHz.615
Scaleknob1 – 10Selects one of ten scales within the current group. In Learn mode, selects the slot where the new scale will be saved.615
Scale SwitchswitchSelects one of three scale groups: 12TET (equal temperament semitones), Octave (any intervals repeating over octaves), or Free (no restrictions on intervals). In Learn mode, determines quantization constraints applied to entered notes.615
SpreadknobAdjusts spacing between oscillator pitches before quantization. At minimum, all oscillators are in unison. Turning up spreads them towards higher frequencies while leaving the root note stationary. Also accesses # Oscillators shift function when Freeze is held.615
Stereo ModeknobShift function (Freeze + Warp): selects panning algorithm for stereo outputs. Three settings: odd oscillators to Out A / even to Out B (lowest); lower half to Out A / upper half to Out B (middle); root oscillator to Out A / rest to Out B (highest).615
TwistknobApplies phase distortion to each oscillator. At minimum, no distortion (pure sine). Turning up morphs the waveshape depending on the Twist switch setting (Ramp, Pulsar, or Crush). Also accesses Freeze Mode shift function when Freeze is held.615
Twist SwitchswitchSelects phase distortion algorithm: Ramp (morphs to sawtooth), Pulsar (narrow pulses), or Crush (bit-crushes the oscillator phase).615
WarpknobApplies wave-folding to the phase-distorted oscillator waveform. At minimum, no folding (sine). Turning up increases folding. Type of folding set by Warp switch. Also accesses Stereo Mode shift function when Freeze is held.615
Warp SwitchswitchSelects wave-folding algorithm: Fold (analog-style, up to 6 folds), Cheb (Chebyshev polynomial, up to 16th order), or Segment (linear/triangle-wave based, 8 shapes).615

Firmware history 2 versions

VersionReleasedNotes
1.1615
1.0.2b615

References 2

  1. [615]
    4ms Ensemble Oscillator Manual v1.1fmanual
    verified 2026-05-21
  2. [616]
    4ms Ensemble Oscillator product pageproduct_page
    verified 2026-05-21