FILTRONIX
Key Features
- Four circuit-inspired filter models cover transistor ladder, state-variable, OTA cascade, and CMOS-style responses.
- Zero-delay feedback processing is used to keep high-resonance sweeps smoother and more cohesive than basic digital filtering.
- 4x oversampling and a 33-tap FIR downsampling filter target cleaner saturation and reduced aliasing.
- ADAA tanh saturation adds nonlinear drive behavior as input level and resonance are pushed harder.
- Low-pass-only design keeps the workflow focused on analog-style sweeps, tone darkening, resonance, and self-oscillation.
- Windows VST3 delivery makes it a lightweight filter insert for DAWs that support modern VST plugin formats.
Description
FILTRONIX is a Windows VST3 filter effect from Push and Groove built around zero-delay feedback circuit modeling. It focuses on analog-style low-pass filtering, resonance, drive, and self-oscillation rather than clean utility EQ work.
The plugin models four historic filter families: a transistor ladder, a classic state-variable filter, a polyphonic OTA cascade, and a British CMOS-style circuit. Each model is meant to react differently around resonance, low-end behavior, punch, instability, and aggressive self-oscillation.
Its sound design comes from more than the filter selector. The Gumroad page documents circuit-model equations, 4x oversampling, a 33-tap FIR downsampling filter, ADAA tanh saturation, and a lookup-table approach for heavier saturation while keeping CPU use manageable.
As checked on May 13, 2026, the official Gumroad page lists the product price as 0 USD and says FILTRONIX is a free VST plugin for Windows. The product is delivered through Gumroad, so the review artifact keeps the download external instead of declaring an unverified R2 download key.
Frequently Asked Questions
What kind of filter plugin is FILTRONIX?
FILTRONIX is a circuit-modeled low-pass filter effect. It is built for analog-style movement, resonant sweeps, saturation, and self-oscillation rather than transparent EQ correction.
Which filter models are included?
The official page lists four modeled circuits: M-Filter, S-Filter, P-Filter, and W-Filter. They are based on transistor ladder, state-variable, OTA cascade, and British CMOS-style filter behaviors.
Does FILTRONIX support macOS?
Not in the current release. The Gumroad page says FILTRONIX is currently Windows-only, with Mac versions planned if the response is positive.
Does it offer high-pass, band-pass, or multimode filtering?
The current Gumroad page says the plugin only features a low-pass filter. The developer notes that multimode support is planned for future updates.
