cs-l

Instruo Cs-L

Dual-core complex oscillator for West Coast harmonic mayhem

26 HP Eurorack module

The Instruo Cs-L is a dual analogue oscillator module combining a sawtooth-core oscillator (Osc A) and a triangle-core oscillator (Osc B) with extensive cross-modulation capabilities rooted in West Coast synthesis philosophy. It features per-oscillator wavefolders, a four-quadrant multiplier, internal VCA-controlled modulation routing, oscillator sync, and a global Index bus for simultaneous modulation depth control. The result is an instrument capable of generating extraordinarily rich, harmonically complex timbres far beyond traditional subtractive synthesis.

Features

  • Two independent contrasting-core analogue oscillators: sawtooth core (Osc A) and triangle core (Osc B)
  • Per-oscillator wavefolder with CV input and attenuverter, normalled to oscillator sine waveforms
  • Per-oscillator symmetry bias with CV input and attenuverter for DC offset before wavefolding stage
  • Four-quadrant multiplier/amplitude modulator with ring, half-wave rectification, and full-wave rectification modes
  • Global Index modulation bus with two internal linear VCAs controlling up to 6 internal modulation routings simultaneously
  • Digitally-controlled internal modulation routing via Index Button shift functions
  • Bidirectional 1V/Oct linking via Link Button
  • Hard Sync Input for Oscillator A (rising edge resets cycle, threshold 2.5V)
  • Soft Sync Input for Oscillator B (frequency lock/X-lock, threshold 2V)
  • Internal sync routing: Osc A sawtooth to Osc B soft sync, or Osc B square to Osc A hard sync
  • LFO mode for Oscillator A (sub-audio frequencies, retains 1V/Oct tracking, resets on Hard Sync)
  • Sub square modes for Oscillator B: fundamental, -1 octave, -2 octaves

Controls & Jacks (53)

  • LFO— Switch Oscillator A to sub-audio LFO range frequencies
  • Osc A Fine Frequency— Fine frequency control for Oscillator A
  • Osc A PWM CV Input— CV input for PWM control of Oscillator A
  • Osc A PWM Output— Pulse width modulation waveform output from Oscillator A
  • Osc A Sine Output— Sine waveform output from Oscillator A
  • Osc A 1V/Oct Input— 1V/Octave pitch control input for Oscillator A
  • Osc A Coarse Frequency— Coarse frequency control for Oscillator A (sawtooth core)
  • Osc A Wavefold CV Input— CV input for wavefold amount on Oscillator A
  • Osc A PWM— Pulse width modulation duty cycle control for Oscillator A
  • Mod— Routes Index-controlled sine waveforms to PWM CV inputs. White: bidirectional cross-modulation. Amber: Osc A to Osc B only.
  • Osc A Triangle Output— Triangle waveform output from Oscillator A
  • Hard Sync Input— Hard sync trigger input for oscillator synchronization
  • Ring— Selects amplitude modulation mode for the Multiply circuit. Cycles through Ring Mod, Half-Wave Rect, and Full-Wave Rect.
  • Wavefold A— Controls the amount of wavefolding on Oscillator A. Center is sine-like; fully right adds rich harmonics.
  • Osc A Sawtooth Output— Sawtooth/Ramp waveform output from Oscillator A
  • Osc A FM Input— Frequency modulation input for Oscillator A
  • Osc A FM Attenuator— Frequency modulation depth attenuator for Oscillator A
  • Index— Global modulation index control for internal routing
  • Multiply Mix— Controls the blend between the multiplied signal and direct oscillator output.
  • Multiply CV Atten— Attenuates external CV going to the Multiply section.
  • AM— Selects amplitude modulation mode for the Multiply circuit. Cycles through Ring, Half-Wave Rect, and Full-Wave Rect modes.
  • Multiply Modulator Input— Modulator signal input for four-quadrant multiplication
  • Osc A Final Output— Final waveform output from Oscillator A (after wavefold and symmetry bias)
  • Osc A Lin/Exp— Toggle between linear and exponential FM response for Oscillator A
  • Osc B Lin/Exp— Toggle between linear and exponential FM response for Oscillator B
  • Index CV Input— CV input for global modulation index control
  • Index Mode— Displays current Index routing states when held. Shows which modulation destinations are active.
  • Osc B Symmetry Bias Input— CV input for waveform symmetry biasing on Oscillator B
  • Osc A Symmetry Bias Input— CV input for waveform symmetry biasing on Oscillator A
  • Depth— Controls the output level of the Multiply circuit. Unity gain at approximately 2 o'clock; beyond adds harmonic clipping.
  • Multiply Output— Output of four-quadrant multiplication/amplitude modulation
  • Osc B FM Input— Frequency modulation input for Oscillator B
  • Osc B FM Attenuator— Frequency modulation depth attenuator for Oscillator B
  • Index Attenuverter— Attenuverter for index CV input
  • Sub Mix— Controls the mix level of the sub-octave square signal from Oscillator B.
  • Multiply Depth Atten— Attenuates external CV input for the Multiply Depth parameter.
  • Multiply Carrier Input— Carrier signal input for four-quadrant multiplication
  • Osc B Final Output— Final waveform output from Oscillator B (after wavefold and symmetry bias)
  • Osc B Fine Frequency— Fine frequency control for Oscillator B
  • Wavefold B— Controls the amount of wavefolding on Oscillator B. Center is sine-like; fully right adds rich harmonics.
  • Osc B Triangle Output— Triangle waveform output from Oscillator B
  • Osc B 1V/Oct Input— 1V/Octave pitch control input for Oscillator B
  • Osc B Coarse Frequency— Coarse frequency control for Oscillator B (triangle core)
  • Osc B Wavefold CV Input— CV input for wavefold amount on Oscillator B
  • Osc B PWM— Pulse width modulation duty cycle control for Oscillator B
  • Osc B Wavefold— Selects the octave of Oscillator B square output. White: -1 octave. Amber: -2 octaves.
  • Osc B Square Output— Square waveform output from Oscillator B
  • Link— Link Oscillators A and B for parallel frequency tracking
  • Sync— Select synchronization mode (hard sync or soft sync)
  • Soft Sync Input— Soft sync audio input for oscillator synchronization
  • Osc B PWM CV Input— CV input for PWM control of Oscillator B
  • Osc B PWM Output— Pulse width modulation waveform output from Oscillator B
  • Osc B Sine Output— Sine waveform output for Oscillator B

How-To Guides

  • Classic West Coast FM Drone
  • Wavefold Timbre Sculptor
  • Hard Sync Lead
  • Ring Modulation Clangour
  • Gentle LFO Vibrato
  • Evolving Index Modulation Pad
  • Multiplier as Voltage Controlled Amplifier
  • Formant Synthesis Voice
  • Bonnie Racket FM Chaos Voice
  • External Signal Wavefolder

Explore the interactive Cs-L panel on BleepDex — tap any control to learn what it does.

8c571ce