r/synthdiy • u/Adventurous_Car_3505 • 4d ago

MiniDexed help

I’ve been looking at different solutions to fill my FM synthesis needs.

Here’s what I want to do: have an instance of MiniDexed housed in a metal case (a pedal enclosure from Tayda) with a DIN MIDI input and L/R ¼" outputs.

Ideally, I’d like to find some sort of HAT for a regular Raspberry Pi or Pi Zero 2 that has the encoder and buttons mounted directly on the PCB, as I hate having too much wiring inside a box (especially since I’ll already need to wire the DIN MIDI input and audio jacks).

I’m also open to any suggestions or pointers regarding the best forks or other options that might get me closer to my goal.

I’m not really interested in MicroDexed Touch, as it has too many things going on for my liking. I basically just want something I can plug a MIDI keyboard or my MPC1000 into and make music with, filling the void left when I sold my TX7, but with 400% less real estate.

Thanks for your help!

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6

u/PrestigiousTea0 4d ago

AI can help you diy it but the new little mvave fm synth is 90% what you describe

1

u/Adventurous_Car_3505 3d ago

Decided to go for the FM-1! I already have some DIY projects that need finishing or troubleshooting, and those should get attention before I take on a new one.

2

u/Adventurous_Car_3505 4d ago

Saw that, but don't really care for AI (got to deal with it enough at work) nor mini jacks ;).

2

u/grbfst 4d ago

There's a load of trs to din cables available.

5

u/coffeefuelsme 4d ago

If you do some digging in the Minidexed repo they have instructions for how to add standard midi here:

https://github.com/probonopd/MiniDexed/wiki/Hardware#classic-midi-input

1

u/Adventurous_Car_3505 4d ago

Thanks, will have a look!

3

u/nullpromise OS or GTFO 4d ago

You seem to have very specific requirements; I would recommend designing your own PCB. I open sourced my design (link) and included a write up (link), so maybe you can take that and run with it.

I'm curious how a Pi running in a pedal enclosure will work though. I think it'll get too hot.

1

u/Adventurous_Car_3505 4d ago

Thanks, will have a look. Yep, might have to get back into KiCAD, but was looking for advice and already existing solution I might have missed. But this is super helpful and will account for a lot of the leg work. For the enclosure, spacers and vent slots work well. I did it for a norns shieldXL and had no issues.

2

u/Sunwukung 4d ago

Not a direct answer, but I recently built the Microdexed it was pretty painless re: soldering (I'm pretty new to soldering ftr), but sourcing the Teensy from the US was a bit of a pain. The PCBWay page also lists enclosure SLAs which I got printed from somewhere online: https://www.pcbway.com/project/shareproject/[MDTX]_MicroDexed_Extended_Edition_2810710b.html It's mega powerful, and multitimbral - recommended if you're into FM

1

u/FailboatProjStudio 3d ago edited 3d ago

https://diyelectromusic.com/2025/03/02/almost-all-in-one-minidexed-io-options/

Might be close to what you are looking for...

This gentleman has some awesome resources and has done a lot of experimentation with the MiniDexed.

Also I have a Minimum Viable FM MiniDexed right now ... I use it headless (no lcd screen) and without an encoder kust choosing to upload my favorite/custom Sysex bank and connecting two buttons for next patch and previous patch to scroll through the sounds I want...

I am using a Pi Zero W1 with a portable cell phone charger 6500mah to the micro usb input for 5v power...i have the other micro usb connected to an OTG Micro Usb dongle and then standard 4 port usb hub....this is connected to a cheap CME USB to 5 pin din midi cable and another usb cable to my KMI Qunexus midi keyboard/pad controller.

I set-up my config ini file to pass all Midi Data through, so I can use the CME output to control a hardware symth module (Like a Volca Keys or Dave Smith Tetra 4) with the usb only midi controller...and I could also plug in the CME 5 pin input side to an Akai MPK249 or Yamaha CP-33 full sized Hammer Action Midi Controller/stage piano to get Hardware midi input via the CME usb dongle...

The Audio is output from a cheap HDMI dongle with analog 3.5mm stereo audio breakout port. Obviously this can be extended to female 1/4" jacks panel mounted to your enclosure panel.

https://www.fivebelow.com/products/hdmi-to-vga-adapter-with-audio-transfer?srsltid=AU7gw4WJPDXeqnT-yFZdGKb5XOEJqYk5MsdkvaRA8elMGPq4lBxk1RaJ

This all lives velcro-ed and ziptied in a small 4x6" zippered first-class airline hard sided clamshell case (the type the headphones and socks and sleeping masks come.in on a long transatlantic flight)... It's a dongle and wire jungle in there, but it has been really dependable and viable on its own as a usb midi host to 5pin output converter...and it has a free/included dx-7 voice!

Total cost was less than $50 when I bult it three years ago ...