WMD Synchrodyne

Filter, oscillator, Waveshaper and VCA

The WMD Synchrodyne is a wild mix of filter, oscillator, Waveshaper and VCA. The module contains several elements of a traditional synthesizer voice and is an effective addition to any subtractive-oriented system. It is primarily intended as an experimental sound source/filter to push the boundaries of modular synthesis. Synchrodyne was designed to implement a switched capacitor filter(SCF) chip without the need for a microcontroller to control the Clock. The result is an extremely fast analog VCO capable of controlling the SCF over a wide frequency range. In this particular case, the VCO is only responsible for operating the filter. Therefore, a frequency multiplier based on a phase-locked loop was developed so that the VCO can be used as an audio source while still controlling the filter. The SCF has a frequency ratio of 50:1 or 100:1 between the clock frequency and the output frequency. With the PLL, many different relations between input and output frequency can be selected so that the VCO can serve as both an audio source and a control source. A PLL in itself has its own special features. To stabilize the PLL at high transformation ratios, a damping circuit had to be developed. The damping and the "track speed" give the PLL its own sound, a kind of slew limiter and self-modulation. A clear distortion at the output is intentional and is due to the use of single-stage rectifiers at the 12/24dB filter outputs. The Synchrodyne is not a module for beginners, but once you have internalized how it works, it reveals sounds that were previously unthinkable with a comparable module.