DIY Cardboard FM Synth (8 DX7s!) | MiniDexed & Raspberry Pi

I’m a big fan of the open-source DX7 synth, Dexed. MiniDexed takes things to the next level letting you combine 8 DX7s similar to the TX802 and TX816. The best part is that it runs like a dream on Raspberry Pi.

In this video, we’ll build our little cardboard FM synth, talk about the synths that inspired MiniDexed, and demo a bunch of sounds from the performance presets, Classic DX7 Roms, and SEGA YM2612 presets.

0:00 Intro
0:59 What Is It?
2:19 How Do You Make It?
3:54 Installing MiniDexed
6:16 Performance Presets
8:52 Classic DX7 Presets
10:23 SEGA YM2612 Presets
11:38 Wrap-up

Get MiniDexed on GitHub

Floyd Steinberg’s MiniDexed Tutorial @mr_floydst

Additional Links
YM2612 Dexed Presets on GitHub

Dexed for Desktop

King of FM (FREE) by AudioKit Pro | Demo, DX7 Love & Why It Matters

How to Recreate Retro Game Instruments for FREE | NES, SEGA Genesis & SNES

Things used in this build:
Raspberry Pi 3B
Raspiaudio Hat
I2C LCD Display
Micro SD formatted to FAT32
Arturia Midi Keyboard
Male to Female Jumper Wires
Cables for Stereo Audio, USB MIDI, and Radpberry Pi Power

Thanks for Watching!
Nick
Moby Pixel

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[mr_floydst]

Thanks for your shoutout! Great video!

[holotape]

Nice to see a video like this where the dude can actually properly play

[ErikHawk]

Wow, this is awesome! What a cool project. I totally want to build this now. Thank you!

[alanredversangel]

Can't overstate how nice the performance patches are, and touch sensitive. And the reverb is the icing on the cake. Also there's a way to change performances with program changes.

[harrkev]

Quick tip on your soldering job. After soldering the wires, you could insulate them by using some hot glue. If you get your fingers wet by licking them, you can very quickly press on the hot glue to mold it to whatever shape you need.

[jdmaze]

My first watch of this video, I jumped straight to the sound tests. Gawd I love the sound of this synth so much... Thanks for this! :)

[BananasananaB]

Now take it and integrate it into the keyboard. I'm still hoping to do that. Integrate a small NUC that can support VSTi's into a keyboard controller and have it all powered internally. So you turn on the keyboard and it powers the NUC then auto loads a synth. Any VSTi you want to load on it.

I've done that externally with a small Beelink NUC and a lightweight DAW that auto loaded when the NUC booted (to Windows 11) that then auto loaded a default project where I had several different VSTi's loaded on individual channels.

[IBoughtItMyself]

Fantastic overview. Did not know sound is now so straightforward with the Pi.

[jmdfamily]

Love the santa cruz stickers! Great video will try to build!

[flywittzbeats]

Soldering is on point! lol. This thing sounds amazing! Also the video production/presentation is second to none (:

[Unhacker]

OMG, the QY-70! I miss mine, the ultimate Musician's Gameboy. ❤

[System-]

For future reference, the header on your audio board is made for female jumper wire connectors. You could have connected it to the pi with female to female jumper wires instead of soldering it.

[cerebralkaos]

Leaves my TX7 for dead. Have to build this into a 19' rack case and improving to 1/4 inch outputs!

[SimpleDIYElectroMusicProjects]

That's a great video and nice to see the performance presets getting a proper showdown :)

Kevin

[TheFBK]

Korg’s Fm synth the Opsix as far as I am aware is pretty much just a raspberry pi in a fancy case.

[blast_processing]

If the RPI is capable of hosting *8* DX7s emulations -- that's 288 operators configured into 48 voices, each with 6 operators -- surely it's capable of more advanced FM synthesis? Dexed is open-source, so it should be pretty easy (for a competent programmer) to tweak it to emulate the FVX-1 or even better, a fully multitimbral, 24-voice, 8-operator instrument, with the algorithms of the FVX-1 and the waveforms of the TX81Z (if not more).

[peterberghoff]

Incredibly well made video, thank you ❤

[iluvsa]

Very cool build! I am trying to map an Arturia MiniLab the same way - quick question, is the rotary function of the rotary knob being controlled by MIDI? In other words, were you able to control any of the parameter value using a knob or slider on your Arturia? What a time to be alive!

[The_artist_called_The_Engineer]

Great video. A question, could the build be done with a touch screen and an external usb sound module?

[cerebralkaos]

How many voice polyphony does this have?