befaco-octaves-vco

Befaco Octaves VCO

Six stacked octave pulses with per-octave volume and shared PWM

12 HP Eurorack module

Octaves VCO is an additive oscillator that generates six pulse waves across consecutive octaves by frequency-doubling a core triangle oscillator, converting each doubled triangle to a variable-width pulse via comparators. Its character is harsh and funky, with symmetrical PWM applied simultaneously to all octaves and a cascade mixing architecture that produces 'castell-like' symmetrical waveforms rather than the 'staircase' shapes of classic divide-down oscillators. Six individual VCAs with CV control over each octave's volume allow for expressive timbral shaping from subtle to extreme.

Features

  • Core triangle oscillator with 1V/OCT tracking
  • Five frequency doublers generating 2x, 4x, 8x, 16x, and 32x frequency triangles
  • Six comparator-based pulse shapers converting triangles to variable-width pulses
  • Global symmetrical PWM applied to all six octave pulses simultaneously
  • PWM CV input with manual attenuator
  • Hard sync input resets core oscillator for harmonic generation
  • Six independent VCAs, one per octave
  • Per-octave manual level control
  • Per-octave CV level input; manual knob becomes attenuator when CV is patched
  • Cascade mixing architecture: each Out sums all unbroken signals to its left
  • Multi-mix output: splitting the chain at any Out jack creates independent submixes
  • Octave selector switch for base octave selection

Controls & Jacks (26)

  • PWM CV In— Control voltage input for pulse width modulation, passed through the manual attenuator.
  • 8F Level— Manual level control for 8F octave output.
  • Pitch CV 1— Volt per octave control voltage input. Both Pitch CV inputs are summed together.
  • F Level— Manual level control for F (fundamental) octave output.
  • F Level CV— CV control for F octave level. When connected, the manual control becomes an attenuator.
  • 4F Level— Manual level control for 4F octave output.
  • Tune— Sets the pitch of the VCO. C at the center position.
  • 16F Level— Manual level control for 16F octave output.
  • Pitch CV 2— Volt per octave control voltage input. Both Pitch CV inputs are summed together.
  • 2F Level— Manual level control for 2F octave output.
  • 8F Out— Output of the 8x frequency octave. Summed with all unconnected jacks to the right.
  • 16F Out— Output of the 16x frequency octave. Summed with all unconnected jacks to the right.
  • 2F Level CV— CV control for 2F octave level. When connected, the manual control becomes an attenuator.
  • 4F Out— Output of the 4x frequency octave. Summed with all unconnected jacks to the right.
  • F Out— Output of the fundamental frequency octave. Summed with all unconnected jacks to the right.
  • 2F Out— Output of the 2x frequency octave. Summed with all unconnected jacks to the right.
  • 4F Level CV— CV control for 4F octave level. When connected, the manual control becomes an attenuator.
  • 8F Level CV— CV control for 8F octave level. When connected, the manual control becomes an attenuator.
  • 16F Level CV— CV control for 16F octave level. When connected, the manual control becomes an attenuator.
  • 32F Out— Output of the 32x frequency octave. Master output when only this jack is connected.
  • Hard Sync In— Resets the core oscillator when a pulse is received, generating extra harmonics.
  • Pulse Width— Controls the proportion of the period in which all the pulses are UP or DOWN.
  • 32F Level CV— CV control for 32F octave level. When connected, the manual control becomes an attenuator.
  • PWM CV Attenuator— Attenuator for PWM CV control voltage.
  • Tune Range— Select the precision of the Tune control. Full range at left, one octave at center, one semitone at right.
  • 32F Level— Manual level control for 32F octave output.

How-To Guides

  • All Octaves Master Output
  • PWM Drone Sweep
  • Bass and Treble Split
  • Hard Sync Harmonic Crunch
  • CV Timbre Sculpting
  • Percussive Octave Stack
  • Generative Harmonic Randomizer
  • Six Independent Octave Voices
  • Pumping PWM Bass
  • Dual CV Pitch Control

Explore the interactive Octaves VCO panel on BleepDex — tap any control to learn what it does.

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