The Spectral Devastator features a brand new filter core, designed by FSS through finding ways to implement voltage control for a resonant active filter. The method of CV involves passing the audio input through the CV stage, but whilst the CV implementation is non-linear, distortion and waveshaping of the audio occurs, particularly with high resonance. This circuitry also results in a filter that self oscillates not sinusoidally, but with a sawtooth-like waveform.
Two filter sections (highpass and lowpass) can be normalled together to create serial or parallel processing of the same input, whilst the highpass' cut-off control is normalled to the secondary CV input of the lowpass filter via a variable attenuator.
At low resonances, the filter gently rolls off frequencies above the cut-off point. Tweak the resonance past 12 o'clock and the filter begins to growl. Crank it up to 10 and you've got a filter that adds harmonics to your original input, based upon that input's harmonic content. Unplug the input and use the two filter sections as VCOs. Plug audio into the CV inputs and create swarms of noise. Use the highpass section as a VCO and the lowpass section to filter its output, giving you the core of any acid bassline you could ever desire.