How to Build the AI028 Voltage Controlled Matrix Mixer

This is the build guide for the AI028 Voltage Controlled Matrix Mixer

Buy the Eurorack Voltage Controlled Matrix Mixer

Resources
About the AI028 DIY Stereo Matrix Mixer
Tools Needed
BOM (Bill of Materials)
Build Guide

1. Resources

2. About the DIY Voltage Controlled Matrix Mixer

The AI028 DIY Voltage Controlled Matrix Mixer is a 6-input, 6-output Matrix Mixer, with 36 Linear VCAs to control how much each input is fed to each output (0-5V). The Module can distribute audio and/or control voltage, and has a dedicated 5V output for use with passive or active attenuators for manual volume control.

3. Tools Needed

For testing and Calibration:

4. BOM

Category	Part	Quantity	Designation
Capacitor	10uF Capacitor	2	C1-2
Capacitor	10uF Non-Polar Capacitor	6	C7-12
Diode	1N5817 Schottky Diode	2	D1, D2
Hardware	Shrouded Power Header	1	Power
Hardware	Jack	49	A ton of 'em
Hardware	14 Pin Plug Header	4	n/a
Hardware	14 Pin Socket Header	4	n/a
Nut	Nut	49
Regulator	L78L05	1	IC6

5. Build Guide

To start, we need to make the PCB sandwich with the 14 pin headers and solder those. Be sure to reference other images in this guide to ensure the headers are on the right side of the PCB.
Now solder the 49 jacks. I like to start from the bottom row and solder the ground lug (the one that sticks out) from above. Then I soft place the panel and loosly place four nuts to keep the panel in place, just to ensure the jacks are straight. Finally, I finish soldering them from the other side of the PCB. Be thorough.
Now solder the 2 1N5817 Diodes. These will protect the module if power is somehow reversed.
Now solder the Power Header, which will take pressure off the caps we’re about to install.
Now solder the four 10uF caps that are part of the power filtering circuit. These caps are polarized and have a stripe, and must be oriented correctly.
Now solder the six non-polar 10uF Capacitors. They are non polar and can go in either way.
The last step is to solder the Power Regulator as shown above. When assembling the PCBs, the jack board should have the text right side up, and the ground lugs on the jacks should be pointing up. The Power connector will be at the top.
Now We’re done! Perform a Continuity Test and power on if there are no shorts between +, -, and GND.