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.
