Mod Medusa

Shakmat Modular 12HP
LFO RANDOM FUNCTION

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Four-output Euclidean LFO. Replaces triggers of an algo-rhythmic sequencer with full waveform cycles. Symmetry, shape, tables, correlated/independent modes, VCA, assignable gate.

Patch Ideas · 8

★ Quad correlated modulation
Clock into CLK · Main mode · four outputs modulate VCF cutoff, VCA level, FX send, pan · peak sync ON for beat-aligned swells
▸ Show diagram
Patch diagramPatch diagram with 6 modules and 5 connections. Modules: MOD MEDUSA, Clock, VCF, VCA, FX Send, Pan. Signals: 4 cv, 1 clock.MOD MEDUSAClockVCFVCAFX SendPanMode: MN · P Sync: ON · Uni: bipolarClockclkOut 1cvOut 2cvOut 3cvOut 4cvOutclkCutoffcvCVcvLevelcvCVcv1231. backward2. inverted3. 1 per lengthcvclock
★ Quadrature-phase filter sweep
Phase mode · stereo filter cutoff L/R from Out 1 and Out 3 (L/2 shift) · Out 2 at L/4 feeds reverb size · Out 4 at 3L/4 feeds pan
▸ Show diagram
Patch diagramPatch diagram with 5 modules and 5 connections. Modules: MOD MEDUSA, Clock, VCF, Reverb, Pan. Signals: 4 cv, 1 clock.MOD MEDUSAClockVCFReverbPanMode: PH · L=8ClockclkOut 1cvOut 3cvOut 2cvOut 4cvOutclkCutoff LcvCutoff RcvSizecvCVcv1231. L/2 shift2. L/4 shift3. 3L/4 shiftcvclock
★ Track & Hold stepped LFO
A Gate menu = Track & Hold · gate from sequencer · outputs freeze to stepped values between gates · great for melodic CV if fed to quantizer
▸ Show diagram
Patch diagramPatch diagram with 6 modules and 5 connections. Modules: MOD MEDUSA, Clock, Sequencer, Quantizer, VCO, VCF. Signals: 2 cv, 1 pitch, 1 gate, 1 clock.MOD MEDUSAClockSequencerQuantizerVCOVCFA Gate: T&HClockclkA GategateOut 1cvOut 2cvOutclkGategateCVcvOut1v/octV/Oct1v/octCutoffcvcvpitchgateclock
Accelerando ratchet fill
A Gate menu = Accelerando · gate at bar-3 of a 4-bar loop sweeps cycle rate upward for a drum-roll build · normal Euclidean patterns resume after gate release
▸ Show diagram
Patch diagramPatch diagram with 5 modules and 4 connections. Modules: MOD MEDUSA, Clock, Bar 3 Gate, Drum Synth, Drum Envelope. Signals: 1 cv, 1 gate, 1 trigger, 1 clock.MOD MEDUSAClockBar 3 GateDrum SynthDrum EnvelopeA Gate: AccelerandoClockclkA GategateOut 1cvOut 2trigOutclkOutgatePitchcvTrigtrig11. via cycle startscvgatetriggerclock
Compute polyrhythm modulation
Compute mode · Out 1 (L=12, density 4) · Out 2 (L=6, density 2) · Out 3 (L=8, density 2 via 2xL/3) · Out 4 (L=8, density 3 via L-C) · four nested polyrhythms from one clock
▸ Show diagram
Patch diagramPatch diagram with 6 modules and 5 connections. Modules: MOD MEDUSA, Clock, VCO 1, VCO 2, Filter 1, Filter 2. Signals: 4 cv, 1 clock.MOD MEDUSAClockVCO 1VCO 2Filter 1Filter 2Mode: CP · L=12 D=4ClockclkOut 1cvOut 2cvOut 3cvOut 4cvOutclkFMcvFMcvCutoffcvCutoffcvcvclock
Shape + Symmetry live morph
Two LFOs modulate Shape and Symmetry CVs respectively · output mutates from pulse-like exp to smooth sine to sawtooth without changing rhythm · single slow sweep sounds like three different modulations
▸ Show diagram
Patch diagramPatch diagram with 6 modules and 5 connections. Modules: MOD MEDUSA, Clock, Slow LFO 1, Slow LFO 2, VCF, Wavefolder. Signals: 4 cv, 1 clock.MOD MEDUSAClockSlow LFO 1Slow LFO 2VCFWavefolderClockclkShape CVcvSymmetry CVcvOut 1cvOut 2cvOutclkOutcvOutcvCutoffcvAmountcvcvclock
Independent per-voice modulation
Hold Mode 2 s · edit each channel with different length/table/polarity · Out 1 slow sine for pad filter · Out 2 fast ramp for lead volume · Out 3 random for perc pitch · Out 4 anti-euclidean for FX
▸ Show diagram
Patch diagramPatch diagram with 6 modules and 5 connections. Modules: MOD MEDUSA, Clock, Pad VCF, Lead VCA, Perc VCO, Delay. Signals: 4 cv, 1 clock.MOD MEDUSAClockPad VCFLead VCAPerc VCODelayIndependent mode · 4 channels unique: ClockclkOut 1cvOut 2cvOut 3cvOut 4cvOutclkCutoffcvCVcvFMcvFeedbackcv12341. slow sine2. fast ramp3. random4. anti-euclcvclock
VCA-gated envelope substitute
Menu assigns VCA to Out 2 only · sequencer envelope into VCA CV · Out 1 provides free-running filter mod · Out 2 replaces a dedicated envelope for a voice
▸ Show diagram
Patch diagramPatch diagram with 7 modules and 6 connections. Signals: 2 audio, 3 cv, 1 clock.MOD MEDUSAClockEnvelopeVCFVCAAudioOutputMenu: VCA → Out 2ClockclkVCA CVcvOut 1cvOut 2cvOutclkOutcvCutoffcvCVcvInaudioOutaudioOutaudioLaudio121. free2. VCA-gatedaudiocvclock

Behaviors

Euclidean LFO Engine Clock + Length + Density

Each cycle of the LFO maps to a hit in an algorithmic sequence (Euclidean, Anti-Euclidean, Split, Divider etc.). Cycle timing adapts to the gap between consecutive hits.

Correlated Modes Mode button (short press)

Channels 2-4 derive from channel 1: MN (Main: backward/inverted/1-per-length), CP (Compute math), RD (Random fills), PH (Phase: L/4, L/2, 3L/4 shifts for quadrature-like feel).

Independent Mode hold Mode 2 s

Panel controls address one channel at a time. Each of four channels holds its own length, density, shift, shape, symmetry, table, polarity, peak sync. CV inputs remain bound to channel 1.

Peak Sync P Sync button

When ON, wave peaks align with the clock instead of wave starts. Converts sequence feel from attack-on-beat to peak-on-beat — changes perceived rhythmic character dramatically.

Assignable Gate Functions A Gate input + menu selection

Gate performs ratcheting (x2/x3/x4/random), accelerando/decelerando cycle-rate modulation, Track & Hold (freeze outputs when gate low), or One-Shot gating.

VCA Routing VCA CV + menu assignment

Unipolar VCA controls amplitude of any subset of the four outputs selected via menu. Enables a single envelope to shape only the outputs that need shaping.

Clock Divider menu + Table button

Divides incoming clock 1-8 before the Euclidean engine. Useful when feeding a fast master clock but wanting slow modulation periods.

Controls

Channel 1 (or selected channel) Length Potentiometer Sets sequence length 1-8 steps; Length+/Menu button extends to 9-16.
1-8 default · 9-16 via Length+ · CV-addressable
Channel 1 (or selected channel) Density Potentiometer Number of LFO cycles distributed across the pattern length. CCW mutes, CW fills.
0 = muted · max = trigger-per-step equivalent · CV-addressable
Channel 1 (or selected channel) Shape Potentiometer Continuously morphs waveshape from sigmoid through exponential, logarithmic, linear, to sinusoidal.
Continuous · CV-addressable · paired with Symmetry for full wave design
Channel 1 (or selected channel) Symmetry Potentiometer Balances rise vs fall time of each cycle. Full CCW = ramp down, CW = ramp up, center = triangular/sine symmetric.
Continuous · CV-addressable
Clock / Gate Tap / Manual Gate Button Acts as tap tempo (green mode) or manual gate at the Assignable Gate input (red mode, set in menu).
Green = tap tempo · Red = manual A Gate
Polarity Uni Button Toggles unipolar (0-5V) or bipolar (-5 to +5V). Correlated mode applies to all channels; independent mode per channel. Hold 2 s to store state to non-volatile memory.
Lit = unipolar · unlit = bipolar · hold 2 s = save state
Phase P Sync Button When ON, waves sync their peaks to the incoming clock rather than their starting points.
OFF = start-of-cycle sync · ON = peak sync
Tables & Clock Divider Table / Division Button Selects one of 8 rhythmic tables. In menu: sets incoming clock divider 1-8.
Green LEDs: 1 Straight · 2 Classic Euclidean · 3 Revised Eucl · 4 Anti-Eucl · Amber: 5 Descelerando · 6 Accelerando · 7 Divided · 8 Fill Next
Correlation / Gate assignment Mode / A Gate Button Cycles Main / Compute / Random / Phase correlation modes. Hold 2 s to enter independent channel edit. In menu: configures Assignable Gate function.
MN · CP · RD · PH · hold 2 s = indep edit · A Gate: Ratchet x2/x3/x4/rand · Accel/Decel · T&H · One-Shot
Channel / VCA assignment Shift +/- Buttons Rotates sequence forward/backward one step. Hold both 2 s = reset shift. In menu: assigns which channels the VCA input controls.
Menu mode: + / - select VCA-affected outputs
Global Length+ / Menu Button Toggles 9-16 step extended range; hold 2 s to enter options menu (A Gate, VCA routing, clock divider).
Lit = 9-16 range · hold 2 s = options menu

I/O

IN · 8

  • Clock -5 to +5V CLK
    External clock driving the Euclidean sequence engine.
  • VCA CV 0 to +5V CV
    Unipolar VCA CV; normalized to 5V. Assignable to any subset of the four outputs via menu.
    NORM → +5V
  • Length CV -5 to +5V CV
    CV offset added to Length pot.
  • Symmetry CV -5 to +5V CV
    CV offset added to Symmetry pot.
  • Shape CV -5 to +5V CV
    CV offset added to Shape pot.
  • Density CV -5 to +5V CV
    CV offset added to Density pot.
  • Reset -5 to +5V
    Resets the wave sequence to step 1.
  • Assignable Gate 0 to +5V GATE
    Gate input performing the menu-selected function: Ratchet (x2/x3/x4/Random), Accelerando, Decelerando, Track & Hold, One-Shot.

OUT · 4

  • Out 1 -5 to +5V
    Primary LFO output carrying the panel-set waveform.
  • Out 2 -5 to +5V
    Correlated or independent LFO channel 2. Correlated relationship defined by mode (Main=Backward, Compute=L/2 & C/2, Random=Soft Fill, Phase=L/4 shift).
  • Out 3 -5 to +5V
    Correlated or independent LFO channel 3. Correlated: Main=Inverted, Compute=2xL/3 & 2xC/3, Random=Hard Fill, Phase=L/2 shift.
  • Out 4 -5 to +5V
    Correlated or independent LFO channel 4. Correlated: Main=1 cycle per length, Compute=L-C, Random=full random, Phase=3L/4 shift.