4ms-envvca

4ms EnvVCA

Analog envelope, slew limiter, and VCA in one

8 HP Eurorack module

The EnvVCA is a 100% analog envelope generator, slew limiter, and VCA in one module. It produces linear envelopes ranging from audio-rate modulation up to 30-minute sweeps, with an integrated exponential VCA whose gain tracks the envelope output. Its Follow jack enables slew limiting, ASR/ADSR envelope generation, portamento, and exotic audio filtering, making it a deeply versatile utility voice-shaping tool.

Features

  • 100% analog linear envelope generator
  • Low-noise low-distortion DC-coupled exponential VCA
  • Rise and Fall times from 100 microseconds to over 30 minutes via CV
  • Sliders and switches only: approximately 1.25ms to over 2 minutes
  • Independent Rise and Fall sliders with Slow/Med/Fast range switches
  • Time CV jack with independent attenuverter knobs for Rise CV and Fall CV
  • Blue/red LEDs on Rise CV and Fall CV indicate modulation strength and polarity
  • Cycle button for looping LFO-style envelopes
  • Cycle jack for gate-controlled cycling with inverted logic when button is on
  • Trigger jack fires one-shot envelopes on rising edges above 2.5V
  • EOR (End of Rise) gate output for chaining and sequencing events
  • Env Level slider independently controls Env jack output without affecting VCA gain

Controls & Jacks (19)

  • Cycle— Toggle cycling/LFO mode. When on, envelopes cycle continuously. Button illuminates orange when cycling.
  • Fall CV— Attenuverter controlling how much the Time CV jack affects fall time. Turn right to lengthen with positive CV, left to shorten with positive
  • Rise CV— Attenuverter controlling how much the Time CV jack affects rise time. Turn right to lengthen with positive CV, left to shorten with positive
  • Time CV— Modulates rise and fall times through Rise CV and Fall CV attenuverters.
  • EOR— End of Rise gate output for chaining and sequencing events.
  • Cycle— Toggles cycling state with a gate signal.
  • Audio Out— VCA output with audio modulated by envelope.
  • Env— Envelope output, attenuated by Env. Level slider.
  • Follow— Slew limiter input for complex envelope generation and filtering effects.
  • Trigger— Fires a one-shot envelope when receiving a trigger of at least 2V.
  • Audio In— Audio input to the VCA.
  • Rise— Selects rise time range: Fast (2.5Hz to 800Hz), Med (20 sec to 18Hz), or Slow (5 min to 1.5 sec).
  • Rise— Controls rise time of envelope. Move up for slower rise, down for faster rise. Range depends on Rise switch position. White LED indicates en
  • Rise CV LED— Indicates strength and polarity of Time CV modulation on rise time. Blue = lengthening, Red = shortening.
  • Fall— Controls fall time of envelope. Move up for slower fall, down for faster fall. Range depends on Fall switch position. White LED indicates en
  • Fall— Selects fall time range: Fast (2.5Hz to 800Hz), Med (20 sec to 18Hz), or Slow (5 min to 1.5 sec).
  • Fall CV LED— Indicates strength and polarity of Time CV modulation on fall time. Blue = lengthening, Red = shortening.
  • Env.
  • Env. Level— Attenuates the envelope output on the Env jack from 0V (bottom) to 10V (top). Does not affect internal VCA envelope. White LED indicates env

How-To Guides

  • Basic Cycling Notes with VCA
  • Clock-Triggered Notes
  • ASR Sustain Envelope from Gate
  • ADSR Envelope with Attenuator
  • Ratcheting Burst Effect
  • Advanced Ratcheting Bursts
  • Exponential and Logarithmic Envelope Shapes
  • Portamento Glide on CV Sequences
  • Slew Limiter Low-Pass Audio Filter
  • EOR Gate for Sequential Event Chaining

Explore the interactive EnvVCA panel on BleepDex — tap any control to learn what it does.

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