Sequential Circuits Pro-One based ADSR for Eurorack


For this item we offer a CHIPSET which contains the following:

For all other components required, please see the build document.


Now available as a full kit for DIYers!

CEMvelope is based on the legendary ADSR section of the Sequential Circuits Pro-One monosynth, with minor adaptations to integrate it into Euro format. Smooth and snappy!

It has a gate input as well as a trigger input, the trigger input works in conjunction with the gate input for multiple triggering from a suitable controller device.  For regular use, you can just use a gate input to access all features. Or use a gate input as well as patching additional modulation (an LFO perhaps) via the trigger input. Please note that the trigger input will not work in isolation, but only when the gate input is high.

  • Gate input only: regular ADSR behaviour
  • Gate input plus Trigger input: multiple triggering ADSR behaviour
  • Trigger input only: no output

CEMvelope has at it’s heart a CEM3310 or AS3310. You can source your own chip, of buy direct from me when you order your PCB set and panel.

Product Specifications





5V draw


12V draw


-12V draw