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A 19-channel trigger to MIDI module with customisable MIDI mappings for Eurorack (DIY Kit)
Synth
MIDI
Teensy

DrumFiend

Sold by Divergent Waves

$127.46

No tax for United States [change]
Stock available: 1
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Original Design
This product was designed by Divergent Waves. By buying this product you support original hardware creators.

DrumFiend is a trigger-to-MIDI processor. Send it triggers, and it’ll send out MIDI notes to a connected drum machine.

With the default firmware, DrumFiend is set up with a drum map for the DrumBrute Impact with each trigger input corresponding to a drum. Inputs on the left and right hand side are the normal and “colour” versions of the various drums, with trigger input 19 reserved for the cowbell.

DrumFiend’s inputs trigger at levels above 2.5v and may be run all the way up to low audio rates.

As DrumFiend runs CircuitPython, changing the drum map to output different MIDI notes is as easy as plugging it in to your computer. You can even completely change the module’s function if you want to!

DrumFiend supports both MIDI-A and MIDI-B TRS-MIDI variants, switchable with jumpers on the back of the module.

For DIY kits, all SMD parts are pre-soldered!

Note: In addition to the module, you will also need a TRS to MIDI cable to use this with other (non-TRS) MIDI gear.

Links to code and documentation

Documentation (github.com)

Code (github.com)

Design Files (github.com)

Product HS Code: 92099480

Shipping policy

Shipping weekly on Mondays, but if I have kits or parts ready to go the shipping might be much faster.

Products will always be sent recorded and insured, with duty paid where possible, although this is dependent on the country. Declared value for international shipping will match the retail value.

Delivery to the US has become a little... complicated. Please drop me an email (hello@divergentwaves.co.uk) for a quote if you wish to purchase PCB & Panel sets, kits, or other parts.

The seller

Divergent Waves

Divergent Waves logo

Gloucester, UK
0 orders since Apr 26, 2026
Small-batch Eurorack modular synthesizer kits and built modules from Divergent Waves.
I started to build Eurorack synthesizer modules at the start of 2020, learning as I went. Now I’d like to share some of them with you.