WMD Synchrodyne
VCO + PLL frequency multiplier + switched-capacitor filter sound source
14 HP Eurorack module
The WMD Synchrodyne is a multi-part experimental voice that chains a sawtooth-core VCO into a Phase Locked Loop (PLL) frequency multiplier/divider, which in turn clocks a switched-capacitor multimode filter (SCF). The VCO's pulse output drives the PLL; the PLL multiplies/divides that frequency to clock the filter so the VCO simultaneously acts as audio source and filter-tracking control. Track Speed, Damping and Influence shape how aggressively the PLL locks, giving it slew, self-FM and over-tracking behaviors. A front-end VCA + four-stage wavefolder feed the filter, and single-stage wavefolders sit on the -12 dB and -24 dB taps for added grit. Designed to be pushed into instability and self-oscillation.
Features
- Sawtooth-core TempCo VCO with range ~0.02 Hz to over 400 kHz
- Calibrated 1V/oct input and rising-edge hard-sync input
- Linear (AC/DC) and exponential (DC) FM with bipolar attenuators
- Phase Locked Loop frequency multiplier/divider
- Selectable multiply (x2-x1024) and divide (div 2-9) ratios via rotary switches
- Variable Track Speed and Damping for PLL slew, self-FM and over-tracking
- Influence CV input to perturb and animate the PLL lock
- Phase Delta output reveals PLL lock state with self-PWM
- Switched-capacitor multimode filter (LP/BP/HP) with 50:1 / 100:1 ratio
- Simultaneous 2 Pole (-12 dB/oct) and 4 Pole (-24 dB/oct) outputs, 180 degrees out of phase
- Stable self-oscillation, most prominent on the 4 Pole output
- Voltage control of filter resonance via attenuated CV input
Controls & Jacks (33)
- Multiply
- Multiply Fine
- Divide
- PLL Out
- Phase Delta Out
- Influence In
- Influence
- Track Speed
- Damping
- CLK In
- Filter Mode
- Filter Ratio
- Fold
- Filter In
- Resonance
- VCA
- Resonance CV
- VCA CV
- Resonance CV In
- Coarse
- Fine
- Exp FM
- Lin FM
- Sync
- 1V/Oct
- Exp FM In
- Lin FM In
- 2 Pole Out
- 2 Pole WaveFold Out
- 4 Pole Out
- 4 Pole WaveFold Out
- Saw Out
- Pulse Out
How-To Guides
- Self-Oscillating Filter Drone
- Pitch-Tracked Filter Voice
- Over-Tracking Chaos
- Wavefolded Distortion
- External Clock as Filter Source
Explore the interactive Synchrodyne panel on BleepDex — tap any control to learn what it does.
