Following the recent VCO DIY module, Erica Synths had announced availability of the latest module in its series of educational DIY kits in cooperation with Moritz Klein.
The mki x es. EDU VCA is simple, yet efficient dual VCA for any Eurorack system. It has DC coupled inputs, so you can use the VCA for both audio and CV signals.
Inputs of the second VCA are normalled to the first one, which allows splitting of the audio signal to both VCA or control both VCAs with a single CV. A 60 page build manual explains electronics behind the module and provides step-by step build instructions.
The DIY VCA module is available for purchase for 55 EUR (excl. VAT) / $69 USD.
More information: Erica Synths