Nekyia Circuits - Occult

Nekyia's Occult is an analog triangle-core VCO/LFO that centers around two waveshaping circuits that transform basic waveforms into something far more interesting. This oscillator provides nine concurrent waveform outputs, including Sine, Triangle, Square, and Pulse waves, along with a PWM Sawtooth, two Sub-oscillator outputs (Sub-1 and Sub-2), and the processed signals from both the Shaper and a distinctive Pulser waveshaping circuit. The Pulser circuit, based on Ian Fritz's double pulser design, adds odd harmonics by introducing pulse signals derived from the input wave itself. Meanwhile, the Shaper section provides a crossfader that blends the normalized sine wave with processed Pulser output, creating smooth morphing between cleaner and more harmonically rich sounds.

Through-zero FM gives this oscillator its distinctive character. It enables frequencies to cross into negative values, delivering a broader and more seamless spectrum of sounds while eliminating the abrupt "frequency wrapping" artifacts found in conventional FM synthesis. The results are more symmetrical and musical, with sidebands that stay centered around the base frequency even during extreme modulation. Combined with both hard and soft sync modes plus PWM affecting both pulse and saw outputs simultaneously, Occult can deliver a lot of different forms of textures. With voltage control over every parameter and a frequency range spanning from 20-second LFO cycles to well above audio rate, it works equally well as primary voice or modulation source.

Features:

• Triangle-core VCO/LFO with nine simultaneous outputs
• Through-zero FM with attenuator control
• Pulser waveshaper circuit inspired by Ian Fritz design
• Shaper crossfader with external input and invert option
• PWM affecting both pulse and saw wave outputs
• Hard and soft sync modes
• Sub-octave outputs (-1 and -2 octaves)
• CV control over all parameters
• Audio/LFO switch with 20-second to 20kHz+ range