A State-Variable Filter is an active filter that uses multiple feedback techniques to produce filter responses (LowPass, BandPass and HighPass) from a single filter with user selection.
Classical SVF filters include controls for Filter Frequency, Filter Q and Gain.
With the ASVF-212, we included deep LFO control for the device’s parameters. A variety of textures and horizons of modulation morphing can be created by routing destinations such as Filter Freq, Filter Q, Low-High Filter Response, and Notch-Peak FIlter Response.
The ASVF-212 has an additional Notch Filter (Band Stop filter) and Peak Filter (BandPass filter).
The device can also take advantage of Envelope Follower tricks with modulation destinations for Filter Freq, Filter Q, Low-High Filter Response, and Notch-Peak Filter Response with a few Envelope Follower detection modes. 
Envelope Follower can work with main incoming signal or additional external input.
What makes the SVF-212 different from a typical SVF filter? It is a Stereo filter-bank (LP, HP, BP, Notch, Peak filters) with deep LFO and Env. Follower modulation.
The ASVF-212 includes a Blend knob (Dry/Wet mixture of incoming and processed signals) to create more interesting and creative effects. The user can use the included hard clipped Limiter to control the final signal by adjusting the necessary Gain and Pre-Gain (unprocessed) levels. Drive works as overdrive and compressor effect.
Filter at higher Filter Q values have small oscillation. In version 2.0 now is possible to activate Filter Self-Oscillation with filter keytracking, which allows you to use the filter as oscillator controllable by midi keys.
The ASVF-212 is a modern stereo SVF filter with advanced features and classical analog SVF possibilities. It allows for a lot of variations of active filtering, resulting in a unique sound.