Vostok Instrument Atlas Multimode filter (VCF) with three filter modes available per channel, 4p-LP, 2p-HP, and 4p-BP. Cover filtering technique, from filter sw
ATLAS - Quad Core Multimode Filter
Vostok Instruments
The Vostok Instument Atlas (VCF) filter cores have been carefully designed and tweaked to be pristine without losing character. With three filter modes available per channel, 4p-LP, 2p-HP, and 4p-BP, Atlas can cover almost any filtering technique, from superb filter sweeps to multi-slope resonant patches.
Thanks to its precise resonance circuit, each core creates a clean sine wave when self-oscillating. Excite the inputs with fast trigger or gate signals, and you will get TR-like drum sounds, from deep kickdrums to nice toms and congas.
In addition, the module counts with a CV-controlled Interpolating Scanner circuit that morphs softly between each filter output, creating new shapes and timbres as it fades between the channels.
Atlas user manual - Vostok Instruments