AI Synthesis is a master of producing decent, useful, unfussy, simple and good value Eurorack modules. The AI007 Quad VCA Mixer exemplifies this by being a perfectly useful 4-channel mixer and VCA.
There are no surprises. The AI007 does exactly what you imagine it will. 4 inputs, 4 outputs with 4 level controls over the amplifiers. Each channel has a CV input so that you can control the levels with voltage – it’s a Quad VCA. On the mixing side you have a Mix output that takes any of the channels that don’t have something plugged into their own output making it usefully versatile. A nice bit red knob provides an overall mix output level.
The only other control is a small knob that sets the response curve for each VCA from linear to exponential.
It doesn’t have to be all about audio either. You can use the Quad VCA Mixer to mix control voltages. This could be things like combining sequences for transposition, generating interesting LFO waveforms or attenuating other modulators.
Each channel has a bi-colour LED indicator that shows green for positive, red for negative and nothing for zero voltage. This is more useful when using CVs because at audio rate the lights are changing so fast you really only see amber.
That’s it and honestly, that’s all you’re after in a useful VCA.
AI Synthesis see themselves as educators and offers the AI007 as a full kit and a PCB/Panel as well as fully built. They provide full building instructions and that makes this an ideal kit for a DIY novice. The PCB is $15, a full kit $109 and the built version is $189.