Vostok Instruments Atlas
Quad-core morphing multimode filter — 80s gain-cell sound with a CV-scanned bank.
16 HP Eurorack module
Atlas is a 16HP quad multimode filter built around four gain-cell-based filter cores, with each channel offering three filter modes (4-pole LP, 2-pole HP, 4-pole BP), independent FREQ and RES controls, two CV inputs (a dedicated frequency CV and a switchable FM2/RES input), and resonance compensation that keeps level steady at high Q. Beyond the per-channel outputs, an Interpolating Scanner Bank takes all four filter outputs and morphs smoothly between them via the SCAN fader and SCAN CV input, turning the module into a CV-swept filter-bank instrument with one output that continuously morphs filter colors.
Features
- Four independent gain-cell multimode filter channels
- Three filter modes per channel: 4-pole LP, 2-pole HP, 4-pole BP
- 20 Hz to 20 kHz frequency range
- Self-oscillates above ~2 o'clock on the RES knob — use as a pure sine source
- Resonance compensation circuit keeps level steady at high Q
- Dedicated FREQ CV input per channel (10 Vpp)
- Switchable secondary CV input per channel — selects between FM2 (extra frequency CV) or RES (resonance CV)
- Daisy-chained audio inputs — one source feeds all four channels
- Daisy-chained FREQ CV — one CV sweeps all four channels together
- Interpolating Scanner Bank morphs continuously between the four filter outputs
- SCAN fader + SCAN CV (10 Vpp) drive the morph between channels 1-4
- Per-channel filter outputs available alongside the scanner output
Controls & Jacks (39)
- Ch 1 FREQ
- Ch 1 LED
- Ch 2 LED
- Ch 3 LED
- Ch 4 LED
- Ch 1 Mode
- Ch 2 Mode
- Ch 3 Mode
- Ch 4 Mode
- Ch 2 FM2/RES Select
- Ch 4 FM2/RES Select
- SCAN
- Ch 1 FM2/RES Select
- Ch 1 RES
- Ch 1 In
- FREQ CV 1 In
- Ch 1 Out
- FM2/RES CV 1 In
- FREQ CV 2 In
- Ch 2 FREQ
- Ch 2 In
- FM2/RES CV 2 In
- Ch 2 Out
- Ch 2 RES
- FREQ CV 3 In
- FM2/RES CV 3 In
- Ch 3 In
- Ch 3 Out
- Ch 3 RES
- Ch 3 FREQ
- Ch 3 FM2/RES Select
- Ch 4 In
- FREQ CV 4 In
- FM2/RES CV 4 In
- Ch 4 Out
- Ch 4 RES
- Ch 4 FREQ
- SCAN CV In
- SCAN Out
How-To Guides
- CV-Scanned 4-Color Filter Bank
- Stereo Filter (Ch 1+2)
- Self-Oscillating Sine Drone
- CV-Swept Resonance With FM2/RES Select
- Performance Morph Across Four Modes
Explore the interactive Atlas panel on BleepDex — tap any control to learn what it does.
