Emergency Bass Drop Module

Passive switch module for Eurorack created from emergency push button. Includes links to .STL files for 3D printing the module parts.

Emergency Bass Drop Module
Emergency Bass Drop module for Eurorack. Switch your trigger signal from A to B.

This is a simple passive switch modular synth module for Eurorack. Emergency push button is used as a switch component. Can be used for both ways by routing trigger signal either to A or B output or other way around by switching from trigger signal A to trigger signal B.

What is Eurorack?Wikipedia answer: Eurorack is a modular synthesizer format originally specified in 1995 by Doepfer Musikelektronik. It has since grown in popularity, and as of 2022 has become a dominant hardware modular synthesizer format, with over 15,000 modules available from more than 1000 different manufacturers ranging from DIY kits and boutique, cottage-industry designers to well-known, established synth mass-manufacturers like Moog and Roland.

Bill of Material

Requires only few parts:

  • Emergency stop switch, e.g. this from Amazon.de ~13€
  • 3.5mm jack socket (3 pce), e.g. this from Amazon.de ~9€/5 pce. There are cheaper sets in Aliexpress etc. ...and also mono socket would be better for Eurorack but I had these spare stereo ones available so used them.
  • Wires
  • 3D printed panel and button


It's just a switch 🙃



Had couple of designs for the front panel. Settled on this one that tries to visualize the audio waves rushing from the button to the audio jacks.

You can download the 3D printable STL files from Printables.com:
Emergency Bass Drop Module for Eurorack by Tommi L. | Download free STL model | Printables.com

3D printable parts. Front and back panels, button, and button collar.
Sanded and spray painted the front panel after the print.
Added a small slot for wires so that it keeps the wiring clean and tidy. Small NASA text as additional detail :)

Join the conversation at Mastodon. Any simple ideas to build next?

Tommi Laukkanen (@tlaukkanen@fosstodon.org)
Attached: 2 images Made Emergency Bass Drop #Eurorack #ModularSynth module. Panel and button designed in #Fusion360. Front panel & button spray painted after #3dPrinting. Used passive emergency push button as switch. This will drop the bass in style :mastodance: 😺 🎶