This module is part of my Eurorack series. It’s a voltage controlled amplifier made out of a minimal set of components. It works great in conjunction with an envelope generator and makes your synth sound more natural. There are a lot of applications like shaping different sounds, side-chaining and so on.
More details and assembly instructions at https://polykit.rocks/vca
Disclaimer: Kits or PCBs like this require a certain experience to assemble. A set of tools and basic understanding of electronics and components are required. Please take great care while assembling it. All kits and PCBs are sold at the purchasers risk. Used or assembled kits can't be returned.