The AS3364 is a low cost, easy-to-use quad linear VCA--4 high quality voltage controlled amplifiers on a single IC. Since most analog function generators are RC based and thus have an exponential voltage output curve, you probably want your VCA's to be linear in their amplification response so you don't end up with "double exponential" voltage controlled amplification, which usually sounds, well, not good.

The project uses an MCP6004 quad rail-to-rail op amp to buffer and clamp 4 CV signals to the AS3364's suggested 0-2VDC control voltage for quick experimentation. You are going to want to use this op-amp, or a rail-to-rail op amp similar in spec; more ubiquitous choices like a TL084 or LM324 will lop off low and high CV values while clamping and are not recommended.

I felt it was easier to design and build this board then mess around with breadboarding, but the PCB could be used for audio projects as-is.

Mixers, panners, amplitude modulation, and voltage controlled filters are a few of the projects one could create using this simple design as a starting point.

Kicad 9 files are included below.

More details abut the project are in this blog post: https://audiodiwhy.blogspot.com/2025/03/as3364-experimenters-board-low-parts.html

Have fun!