The new and updated version of the LOOPING VC-ADSR now includes an extra TIMECV input as well as extra switching options for GATE or TRIGGER inputs and selecting between EXPONENTIAL or LINEAR envelope responses.

The Looping VC-ADSR is a 4-stage, loop-able, envelope generator based on the ENVGEN 8C IC from Electric Druid. The individual sections of the Envelope (Attack, Decay, Sustain, Release, Level and Time) can all be individually controlled via CV.

The module has 5 MODES of operation that can be selected via the pushbutton LED switch with the status indicated by the5 LEDs above:

• Normal Envelope – Gate signal at the GATE/TRIG input, fires the ADSR.
• Trigger Mode – Trigger     signal at the GATE/TRIG input fires the AD portion of the envelope. The     sustain control determines the final value the envelope rests at after the     decay portion has ended.
• Gated Looping Envelope – ADSR loops whilst gate signal is high.
• Looping Envelope – ADSR loops regardless of gate signal.
• LIN response (Hold     switch to select between LIN/EXP Mode) – Sets the envelope response to be     Linear. The response is Exponential when the status LED is off.

When the envelope is looping, all 5 controls affect the output. Attack and Decay operate, as one would expect. The Sustain control sets the minimum voltage the decay part of the envelope will decay to. The Release sets a release time from the end of the Sustain period to the beginning of the next cycle. When the Sustain is set to 0 you can use the Release control to add a delay between the Attack and Decay cycles.

In Normal Envelope mode the Sustain CV input can be used with an LFO source to add amplitude modulation that gradually increases as the Envelope transitions from the Attack/Decay part of the envelope into the Sustain part. The Level CV is also a useful point for amplitude modulation or can be used for Velocity Sensitivity via CV.

The Time CV is set so that increasing voltage shortens the overall envelope time to better mimic the sounds of percussive instruments.

The envelope output is0V to +10V and the CV input range is also 0V to +10V. The Gate/Trigger input can work with anything above +5V.

The Looping VC-ADSR is based on the ENVGEN 8C project by Electric Druid. You can read about the microcontroller that the design is based upon here. ENVGEN 8C