EDU DIY Drum Mixer / Output Mixer 2

EDU DIY Output Mixer 2 (mixer for our upcoming EDU DIY Drum system) allows you to build and understand a 4-channel output mixer from scratch. On a breadboard, you’ll set up an inverting summing amp, add a send/return loop, diode distortion, and a headphone driver.

The manual uses clear diagrams and analogies to explain every step, and you can even assemble the kit into a full Eurorack module using the included PCB and panel.

Skill level: Intermediate. Basic electronics knowledge needed. If you’ve completed our VCO or previous Mixer kits, you’re set.

What you’ll learn

Mixing basics:

• Op-amp summing
• Volume controls
• Per-channel sends
• Clean return path

 Distortion design:

• Diode soft-clipping
• Variable distortion

Headphone driver design:

• DC blocking
• High-current output
• Driver stability

What the finished module can do

Once assembled using the included PCB and panel, you’ll get a Eurorack Output Mixer module with:

• 4 input channels with per-channel volume controls
• Send/return loop with per-channel send controls and return control
• Variable distortion insert effect
• Line and Headphone outputs

What’s included

• All components for the breadboard build
• Eurorack panel + PCB for final assembly
• Power cable
• 40+ page illustrated PDF manual as digital download

You’ll also need: a breadboard, jumpers, dual supply (or two 9V batteries and clip connectors).

Want a smoother start? Labor is our purpose-built prototyping platform for our learning kits. It replaces the breadboard, jumpers, and power supply with a single intuitive workspace designed specifically for learning analog circuit design.

About the series
This kit is part of our mki x es.EDU Drums System lineup – a collaboration between Erica Synths and Moritz Klein to make analog drum machine design accessible, hands-on, and genuinely educational.

NB: This kit is designed as a self-guided learning tool. While we don’t offer individual support for failed builds, the manual includes a detailed troubleshooting section to help you diagnose and fix issues yourself – a crucial part of the learning experience.