A filter thatlearns to breathe.

A linear four-pole ladder with a classic 24 dB/octave slope and no nonlinear saturation. It keeps resonant sweeps open and transparent, with seven low-pass, band-pass, high-pass and notch responses.

Topology

Linear TPT/ZDF · 4-pole · Multimode

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Transparent subtractive filtering, clean automation and sources whose original tone should remain intact.

A four-pole ladder with a tanh saturator inside the global feedback loop. Drive adds harmonics and compression, while Character introduces controllable asymmetry.

Topology

Nonlinear TPT/ZDF · Global-loop saturation · Multimode

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Warm basses, broad synth sweeps and analog-style weight without stronger per-stage colour.

A four-stage OTA cascade with soft nonlinear limiting inside every stage. It rounds transients under drive and gives high resonance a fluid, elastic response.

Topology

Nonlinear OTA ladder · Per-stage soft limiting · Multimode

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Pads, leads and resonant movement that should stay smooth rather than abrasive.

A Moog-style four-pole transistor ladder with nonlinear behaviour at every node and inside the feedback path. Drive and Character can turn a clean resonant sweep into something dense, warm and harmonically complex.

Topology

Per-node nonlinear transistor ladder · TPT/ZDF · Multimode

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Classic synth basses, leads and expressive resonant sweeps.

A TB-303-inspired diode ladder with a coupled nonlinear feedback path and dedicated cutoff scaling. Its low-pass response moves from focused filtering to acidic resonance and asymmetric bite.

Topology

Coupled nonlinear diode ladder · Nested ZDF · Low-pass

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Acid lines, sequenced basses and sharp, squelchy automation.

A two-pole MS-20-style dual-integrator cell with positive feedback and nonlinear saturation. Its shallower slope and fast resonance make it sharper and more aggressive than the four-pole ladders.

Topology

Nonlinear Sallen–Key · 2-pole · Multimode

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Drums, noisy material, cutting leads and aggressive resonant sweeps.

An eight-pole ladder with an exceptionally steep 48 dB/octave low-pass slope. Drive and dense resonance make narrow transitions feel dramatic rather than purely surgical.

Topology

Nonlinear 8-pole ladder · 48 dB/octave · Low-pass

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Drastic band limiting, hard spectral transitions and deep synth filtering.

Six topology-preserving all-pass stages create three moving notches while preserving the dry fundamental. Rate and Depth animate an exponential sweep, while Feedback raises and narrows the surrounding peaks.

Topology

6-stage TPT all-pass · ZDF feedback · Stereo LFO

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Guitars, pads, electric keys and wide stereo movement.

An eight-pole Type I low-pass with an equiripple passband and a 48 dB/octave final slope. Increasing Ripple trades passband smoothness for a more abrupt, characterful transition.

Topology

Chebyshev Type I · 8-pole SVF cascade · Low-pass

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Steep synth sweeps and strong spectral separation where audible passband texture is welcome.

A one-directional phaser whose notches appear to rise or fall without reaching an endpoint. Center places the effect in the spectrum, Rate controls its motion and Feedback deepens the continuous sweep.

Topology

Elliptic phase splitter · Barberpole all-pass · Multinotch

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Drones, transitions, ambient layers and hypnotic perpetual motion.

A nonlinear state-variable filter with low-pass, band-pass, high-pass and notch outputs. Its antisaturated damping path supports stable fast modulation and bounded self-oscillation at the top of the Resonance range.

Topology

Nonlinear TPT state-variable filter · Antisaturated · Multimode

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Audio-rate cutoff modulation, flexible sound design and playable resonant tones.

A six-pole elliptic low-pass with finite transmission zeros and a fixed 60 dB stopband target. Ripple trades passband flatness for an exceptionally narrow transition around cutoff.

Topology

Cauer / elliptic · 6-pole SVF cascade · Low-pass

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Extreme band limiting and precise isolation where a small amount of passband ripple is acceptable.

A 100% wet single-sideband frequency shifter that moves every partial by the same number of hertz rather than by a musical interval. Feedback turns the shifted spectrum into metallic, inharmonic spirals in either direction.

Topology

Quadrature phase splitter · SSB shift · ±2 kHz

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Metallic textures, dissonant motion, subtle detuning and experimental effects.

An eight-pole Butterworth-transformed filter with a flat passband and a resonance peak whose height survives the high-order transformation. It provides steep LP, BP, HP and notch responses without passband ripple.

Topology

2nd-kind Butterworth transform · 8-pole · Multimode

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Smooth but steep filtering when the wanted band should remain neutral and resonance clearly defined.

A six-pole inverse Chebyshev low-pass with a maximally flat passband and an equiripple stopband. Finite transmission zeros create strong rejection beyond cutoff without adding ripple to the wanted band.

Topology

Chebyshev Type II · 6-pole SVF cascade · Low-pass

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Steep cleanup, retaining a flat passband and suppressing unwanted upper-band content.

Four resonant 12 dB/octave state-variable cores create two independently spaced peaks per stereo side. Radiate L and Radiate R animate the spacing separately; 4-Peak Mono folds all four peaks into one channel for dense, vocal formants.

Topology

4 × TPT state-variable cores · Stereo dual-peak / mono quad-peak

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Talking sweeps, animated formants, wide stereo motion and expressive modulation that turns simple sources into vocal textures.

A cubic-interpolated fractional delay creates a moving harmonic series of notches and peaks. Rate and Depth shape the sweep, while Feedback increases sharpness and metallic intensity.

Topology

LFO-modulated fractional-delay comb · Stereo spread

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Classic jet sweeps on guitars, synths, drums and transitional effects.

A fractional delay followed by a barberpole phase network creates the illusion of endlessly rising or falling flanging. The spacing becomes inharmonic, while Rate, direction and Feedback control the perpetual motion.

Topology

Fractional delay · Barberpole all-pass · Perceptual endless motion

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Risers, ambient layers and evolving transitions that should never appear to reverse.

A static fractional delay produces a harmonic series of peaks and notches. Notch Frequency sets their spacing, while Feedback controls sharpness, ringing and decay.

Topology

Static fractional-delay multinotch comb · No LFO

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Resonator effects, pitched metallic tones, drum-body shaping and tuned spectral colour.