ENVGEN 8C VCADSR Envelope Generator

(3 customer reviews)


144 in stock (can be backordered)

SKU: ENVGEN8 Category:
1 - 9 £5.00
10 - 99 £4.00
100+ £3.00


This chip is a comprehensive upgrade of the previous generation of Electric Druid voltage controlled envelope generator chips, the VCADSR 7B and LOOPENV 1B. The VCADSR had both GATE and TRIGGER inputs, and the LOOPENV featured a MODE CV that allows selection of normal ADSR, Gated looping, or full LFO-style Looping modes. This chip combines the features of both onto a single chip, and removes the need for a crystal and resconstruction filter. It also improves the output sample rate to 31.25KHz, improves the envelope table resolution, and uses a multiplying DAC for the output, which allows full analog Level CV control without any loss of resolution or calculation errors.

The ENVGEN8C chip keeps the other features of the originals, like full voltage control over all parameters (Attack, Decay, Sustain, and Release)l, and the TIME CV which shortens the overall time of the whole envelope. The TIME CV makes an excellent modulation input for either envelope modulation or LFO frequency modulation. It also adds a PUNCH input which holds the maximum level for a few milliseconds before starting the Decay stage. This is very useful for adding extra punch to short percussive envelopes.

Download Electric Druid EnvGen8C datasheetDruidDatasheetPDF

The datasheet includes example circuit diagrams, example waveforms, and the chip pinout diagram.

If you’d like to program your own chip for personal use, code and further details are available over on the original article about the new Druid chips.



3 reviews for ENVGEN 8C VCADSR Envelope Generator

  1. ehk506 (verified owner)

    Absolutely love this chip, ridiculously easy to use and beautify versatile. 10/10 would ENVGEN8 again

  2. David

    absolutely very great chip!!
    but there might be a bug, i’m not shure.
    what happens: pin3 is grounded for adsr-mode. but when i power up the chip, its always in gated looping mode…
    when i apply first 5v to pin3, then go back to 0v, then it will go into adsr mode. why is that?
    is there a way around it, or am i doing something wrong?

    cheers to your very nice chips! very good work!!

    • Tom Wiltshire

      Yes, I think this is “normal”. It happens because currently the chip only responds to *changes* on the pin, so until something is altered, it doesn’t reset the variables.
      I’ve got one other minor tweak to release for this code, so there’ll be a ENVGEN8B along soon, and I’ll make sure to check this out and fix it while I’m doing it.

      Thanks for the pointer – the more people there are spotting stuff like this, the better the code can get.

  3. Gunnar

    I also have this PIN3 “problem”
    When I power up my system with Normal ADSR mode (grounded) selected I have no signal coming out. I first have to change modes then everything works fine.
    When I power up with Gated Looping or LFO/Looping mode selected everything works fine from the beginning .

    Is an update to ENVGEN8B already available?

    • Tom Wiltshire

      Yes, it is. ENVGEN8C fixes this problem and another minor bug where the chip wouldn’t power up correctly if the Gate was high (which is an over-voltage condition – not good!).
      We’ll have the new chips in stock and the updated code online shortly.

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