4ms Shaped Dual EnvVCA
Dual analog envelope, slew limiter, and VCA in one
16 HP Eurorack module
The Dual EnvVCA is a dual-channel 100% analog envelope generator, slew limiter, and VCA in one Eurorack module. Each channel independently generates linear envelopes with variable rise and fall times spanning audio rates to over 20 minutes, while integrated exponential VCAs shape audio or CV in real time. Its musical character ranges from snappy percussive transients and LFO-style cycling to complex ADSR shapes, portamento, and chaotic self-patched FM oscillators.
Features
- Dual independent analog envelope generators with linear response
- Low-noise low-distortion DC-coupled exponential VCAs
- Rise and Fall times from approximately 1.25ms to over 2 minutes via sliders; up to 10 minutes with CV
- Three-position Fast/Med/Slow range switches per slider
- Time CV jack per channel with independent Rise and Fall attenuverter knobs
- Blue/Red LEDs indicate CV modulation strength and polarity on Rise and Fall CV knobs
- Cycle buttons for looping LFO-style envelopes
- Cycle gate input jack toggles cycling for both channels simultaneously
- Trigger input jacks fire one-shot envelopes
- EOR (End of Rise) gate output on Channel A
- EOF (End of Fall) gate output on Channel B
- Env Out A, Env Out B, and OR jack (highest voltage of both channels)
Controls & Jacks (56)
- Time CV B — Modulates rise and fall times of channel B via Rise/Fall CV knobs. Extends range from ~125µs to ~10min.
- Cycle Button B — Toggles continuous cycling mode for channel B envelope (LFO mode). Button illuminates orange when active.
- Audio Out A — VCA audio output for channel A. Signal level modulated by envelope or external CV.
- Shape Knob A — Controls exponential/logarithmic waveshaping of channel A envelope. Adjusts the curvature of rise and fall segments.
- Audio Out B — VCA audio output for channel B. Signal level modulated by envelope or external CV.
- Trigger A — Fires a single envelope on channel A when receiving a trigger (≥2V rising edge).
- Rise CV Knob A — Attenuverter controlling how much Time CV affects rise time of channel A. Right of center: positive CV lengthens rise. Left of center: inver
- Offset Knob A — Adds DC offset to envelope A output. Clockwise: +0V to +10V offset. Counter-clockwise: 0V to -10V offset.
- Env Out A — Envelope output for channel A. DC-coupled, affected by Level and Offset knobs. Range approximately ±10V.
- Rise CV Knob B — Attenuverter controlling how much Time CV affects rise time of channel B. Right of center: positive CV lengthens rise. Left of center: inver
- Cycle Button A — Toggles continuous cycling mode for channel A envelope (LFO mode). Button illuminates orange when active.
- Shape Knob B — Controls exponential/logarithmic waveshaping of channel B envelope. Adjusts the curvature of rise and fall segments.
- OR — Outputs the highest voltage value between Env Out A and Env Out B at any moment.
- Fall CV Knob A — Attenuverter controlling how much Time CV affects fall time of channel A. Right of center: positive CV lengthens fall. Left of center: inver
- Time CV A — Modulates rise and fall times of channel A via Rise/Fall CV knobs. Extends range from ~125µs to ~10min.
- Fall CV Knob B — Attenuverter controlling how much Time CV affects fall time of channel B. Right of center: positive CV lengthens fall. Left of center: inver
- Offset Knob B — Adds DC offset to envelope B output. Clockwise: +0V to +10V offset. Counter-clockwise: 0V to -10V offset.
- Level Knob A — Attenuates and inverts the envelope A output. At center: no output. Clockwise: positive envelope ~10V. Counter-clockwise: inverted envelope
- EOR — End of Rise gate output for channel A. Goes high when rise ends, remains high during fall, goes low when envelope completes.
- Env Out B — Envelope output for channel B. DC-coupled, affected by Level and Offset knobs. Range approximately ±10V.
- VCA CV A — External CV input for VCA gain on channel A (0-5V = -90dB to unity). Breaks internal envelope-to-VCA connection when patched.
- Follow B — Slew limiter input for channel B. Envelope follows input voltage at rate set by Rise/Fall controls. Active range 0V-5V.
- Trigger B — Fires a single envelope on channel B when receiving a trigger (≥2V rising edge).
- Level Knob B — Attenuates and inverts the envelope B output. At center: no output. Clockwise: positive envelope ~10V. Counter-clockwise: inverted envelope
- Channel A Rise — Selects rise time range for channel A: Fast (2.5Hz-800Hz), Med (20sec-18Hz), or Slow (5min-1.5sec).
- VCA CV B — External CV input for VCA gain on channel B (0-5V = -90dB to unity). Breaks internal envelope-to-VCA connection when patched.
- Follow
- Channel B Fall — Selects fall time range for channel B: Fast (2.5Hz-800Hz), Med (20sec-18Hz), or Slow (5min-1.5sec).
- Fast 2
- Channel A Fall — Selects fall time range for channel A: Fast (2.5Hz-800Hz), Med (20sec-18Hz), or Slow (5min-1.5sec).
- Shape 1
- Channel A Rise — Controls the rise time of channel A envelope. Position determines speed from ~1.25ms to >2min depending on switch position.
- Time
- Shape 2
- Channel B Rise — Selects rise time range for channel B: Fast (2.5Hz-800Hz), Med (20sec-18Hz), or Slow (5min-1.5sec).
- Channel A Fall — Controls the fall time of channel A envelope. Position determines speed from ~1.25ms to >2min depending on switch position.
- Channel B Rise — Controls the rise time of channel B envelope. Position determines speed from ~1.25ms to >2min depending on switch position.
- Channel B Fall — Controls the fall time of channel B envelope. Position determines speed from ~1.25ms to >2min depending on switch position.
- Audio In A 1 — input audio
- Audio In B — input audio
- Shape Knob A — Controls exponential/logarithmic waveshaping of channel A envelope. Adjusts the curvature of rise and fall segments.
- Shape Knob B — Controls exponential/logarithmic waveshaping of channel B envelope. Adjusts the curvature of rise and fall segments.
- Speed Switch A
- Speed Switch B
- EOF — output gate
- Fast 1
- Med 1
- Med 2
- AR
- EOF A→
- RETRIG Jumper A — Controls exponential/logarithmic waveshaping of channel A envelope. Adjusts the curvature of rise and fall segments.
- RETRIG Jumper B — Controls exponential/logarithmic waveshaping of channel B envelope. Adjusts the curvature of rise and fall segments.
- VCA Min Gain Trimpot — Back-panel trimpot adjusting minimum VCA gain, controls bleed and silence between envelope cycles
- Follow A — Slew limiter input for channel A. Envelope follows input voltage at rate set by Rise/Fall controls. Active range 0V-5V.
- Audio In A 2 — Audio input for VCA channel A. Normalized to Audio In B when unpatched.
- Cycle — Gate input that toggles cycling mode for both channels when high. Responds to rising edge.
How-To Guides
- Basic Cycling Notes
- Stereo Cycling Notes
- Synced Notes Using EOF Trigger
- Self-Patched FM Oscillator
- Analog Kick Drum
- Self-Patched Ratcheting
- ASR Envelope with Gate Hold
- ADSR Envelope
- Portamento / Glide
- Sidechain Ducking
- Exponential Envelope Shape
- Trigger Delay with Pulse Width Control
Explore the interactive Shaped Dual EnvVCA panel on BleepDex — tap any control to learn what it does.
