WMD´s Phase Displacement Oscillator is one of THE SYNTHESIZER NETWORK's favorite oscillators. It's a hybrid oscillator module that combines an analog VCO with the possibilities of digital waveshaping.
Is uses the phenomenon of Phase Modulation (PM) e.g. the relative phase difference between the different outputs. The phase can be set or modulated to achieve interesting sounds. The result resembles FM but affects the outputs more without destabilizing the initial frequency. As the PM affects only the relative phase, not the frequency, the PDO can modulate itself which will create complex harmonic sounds. Their frequency seems to change but remains stable in fact.
Version Mk2 is 16HP wide, has 9 instead of 11 knobs and therefore more fingerspace. In addition the signal input routing is better and it consumes less power.
The analog VCO is temperature compensated and thus tracks over five octaves when played thru the 1V/oct input. It is sawtooth-based and beyond the classic wavefrm sine, triangle, sawtooth and square it offers also mixed waves. Controls for coarse and fine frequency tuning, hard sync, exponential and linear FM can be found as well.
Each of the wave forms can be assigned to each phase modulator. The phase (ɸ) of channels 2-4 can be set between -360° and 360° by controls.
The additional SC (staircase) output is the result of the relative phases of the three phase input channels compared to the analog sawtooth waveform. It forms a staircase type output by adding together multiple square waves.
CV inputs: ɸ2, ɸ3, ɸ4 (normalized from 2 over 3 to 4), 1V/oct, exponantial FM, linear FM, sync
outputs: individual outputs 1-4, sum output, staircase output
Current draw +115mA, -40mA
Listen to the demo below on soundcloud by Spite Zoo