19 engines. One living instrument.
Nineteen filter, phase and motion engines — from transistor ladders to a vocal four-peak formant machine. Age gives every instance its own quiet hardware history, while one familiar control surface keeps the whole collection close.
Three families · nineteen engines
Seven circuit models, nine spectral forms and three motion engines. Explore a family or choose any model: each has its own topology, character and reason to exist.
Select an engine for the full signal story. All 19 descriptions remain available without JavaScript.
Engine 01 / Circuit models
Linear 4-pole ladder
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.
Engine 02 / Circuit models
Nonlinear 4-pole ladder
A four-pole ladder with a tanh saturator inside the global feedback loop. Drive adds harmonics and compression, while Character introduces controllable asymmetry.
Engine 03 / Circuit models
Saturated OTA cascade
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.
Engine 04 / Circuit models
Per-node nonlinear ladder
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.
Engine 05 / Circuit models
Coupled resonant ladder
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.
Engine 06 / Circuit models
Dual-integrator cell
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.
Engine 07 / Circuit models
48 dB/oct low-pass
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.
Engine 08 / Spectral forms
Six all-pass stages
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.
Engine 09 / Spectral forms
8-pole Type I
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.
Engine 10 / Spectral forms
Endless phase motion
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.
Engine 11 / Spectral forms
Antisaturated resonance
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.
Engine 12 / Spectral forms
6-pole transmission-zero LP
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.
Engine 13 / Spectral forms
Single-sideband shift
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.
Engine 14 / Spectral forms
2nd-kind multimode
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.
Engine 15 / Spectral forms
6-pole flat-passband LP
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.
Engine 16 / Motion
Fractional-delay motion
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.
Engine 17 / Motion
Endless delay motion
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.
Engine 18 / Motion
Static multinotch
A static fractional delay produces a harmonic series of peaks and notches. Notch Frequency sets their spacing, while Feedback controls sharpness, ringing and decay.
Engine 19 / Spectral forms
Four resonant SVF cores
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.
The drawings describe an engine’s identity, not its measured transfer function. These are visual studies, not an audio demo.
Age · project-stable variation
Age changes the virtual circuit itself — component tolerances, slow thermal movement and internal headroom — without adding noise or placing a vintage effect after the filter.
A project-stable seed recalls the same hardware profile when the session returns.
Three non-periodic drift processes have time constants of 11, 29 and 53 seconds. These are not repeating cycles.
Internal headroom and component variation act inside the model, not as an effect on the finished output.
Move Age to change this visual profile. This illustration does not process audio or predict the sound of a particular instance.
The signal path
Character lives inside the engine: in its feedback, state, saturation and response to time. Gain trims the wet path; the original signal stays separate until the final blend.
A latency-compensated dry path runs in parallel.
The selected topology, its character and supported quality modes.
Level adjustment on the processed signal only.
Bring the dry and filtered paths together.
The stereo peak meter follows the final Mix.
TPT / ZDF methods keep circuit models coherent under modulation. Supported engines offer Auto, Off, 2×, 4× and 8× oversampling. Auto + Ultra targets an internal rate of at least 352.8 kHz; specialised linear and delay engines use their own processing paths.
The essential controls
Controls adapt to the model. Cutoff is relabelled Center or Notch Frequency where appropriate; Shifter instead exposes a separate Shift control spanning ±2 kHz. Resonance becomes Feedback or Ripple when that is what the model uses.
From sub-audio filtering to an open top end. The note readout follows the setting, not detected pitch; frequency and note-name entry are both available.
Resonant emphasis where the topology supports it. The interface becomes Feedback or Ripple when that is what the selected engine actually controls.
Push the supported nonlinear engines into harmonic colour and compression, with fine adjustment near zero rather than a single generic distortion stage.
Controllable asymmetry in Classic, OTA, Transistor, Diode, Sallen-Key and 8-Pole. Clean stays neutral; models without this control keep it out of the way.
Rate moves Phaser, Barberpole, Flanger and Barber Flange. Phaser and Flanger also expose Depth; the barberpole engines offer sweep direction. Comb is deliberately static.
Independently spread two peaks around Cutoff on each stereo side. In 4-Peak Mono, both controls shape the combined four-peak response.
Trim only the filtered signal, after the engine and before Mix. The latency-compensated dry path remains at unity, so Mix at 0% leaves it unchanged.
Blend the original signal with the processed path. The stereo meter reads the final output after Mix, not an internal stage.
Shift-drag for fine adjustment. Cmd-click on macOS or Ctrl-click on Windows/Linux for value entry. Option/Alt-drag Cutoff for semitone steps at A4 = 440 Hz. Double-click to reset; Alt/Option-click never resets a control. Help explains the current model and its controls.
Download the preview
The v0.4.1 developer preview for macOS, Windows and Linux. Five native packages, direct ZIPs and a verified macOS installer.
AU, VST3 and CLAP on macOS. VST3 and CLAP on Windows and Linux, with x64 and ARM64 builds where listed.
Quit your DAW, paste this into Terminal and press Return.
curl -fsSL https://analogfilter.amanita.music/install-macos.sh | bashInstalls AU, VST3 and CLAP for your account. No sudo. Previous versions are saved.
Or run Install Amanita Analog Filter.command from the ZIP. Installation notes ↗
Preview notice: standalone is not included. macOS plug-ins are ad-hoc signed and not Apple-notarized; macOS may ask you to allow the downloaded installer. Windows builds are not yet code-signed.
Release notes
Highlights from the latest published updates, with important compatibility warnings kept alongside them. The complete history remains on its own page.
Installer update only: the plug-in remains version 0.3.3, with no audio changes.