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
github.com/probonopd/MiniDexed
Floyd Steinberg’s MiniDexed Tutorial ‪@mr_floydst‬
• MINIDEXED - honey, I s...
Additional Links
YM2612 Dexed Presets on GitHub
github.com/NickCulbertson/YM2...
Dexed for Desktop
asb2m10.github.io/dexed/
King of FM (FREE) by AudioKit Pro | Demo, DX7 Love & Why It Matters
• King of FM (FREE) by A...
How to Recreate Retro Game Instruments for FREE | NES, SEGA Genesis & SNES
• How to Recreate Retro ...
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
Subscribe! (maybe?)

[@mobypixel]

Thanks for watching! Get MiniDexed on GitHub: github.com/probonopd/MiniDexed

[@mr_floydst]

Thanks for your shoutout! Great video!

[@mobypixel]

My pleasure! MiniDexed is such a cool project. Thanks again for sharing it with the community!

[@peterberghoff]

Incredibly well made video, thank you ❤

[@mobypixel]

Thanks, Peter! I love the demos on your channel. I remember coming across them when I was thinking of building this.

[@analogmatthew]

This content deserves more views! 🔥🙌

[@mobypixel]

Thanks, Matthew! It all hangs in the Algorithm’s tiny robot hands.

[@IBoughtItMyself]

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

[@mobypixel]

Thanks! Yeah, honestly the only challenge was getting the audio into my Mac for recording since it doesn't take a 3.5mm cable as an input, and my Focusrite only has mono inputs. I got a 3.5mm to split XLR cable and that did the trick.

[@SimpleDIYElectroMusicProjects]

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

[@mobypixel]

Thanks, Kevin! Yeah, those presets really take this build to the next level. Instant Phil Collins. 😂

[@jdmaze1]

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! :)

[@mobypixel]

Thanks, @jdmaze1! Yeah, they did a great job with the presets.

[@flywittzbeats4008]

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

[@mobypixel]

Thanks homie! The performance patches really make it sound unique. I’m working on another synth project that I’ll hopefully have out next week.

[@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.

[@JakobHaq]

Nice, what a fun project. Have to try it out. 👊

[@mobypixel]

Thanks Jakob! Yeah, there are a few Raspberry Pi synths, but this one brings something unique that we can't even get on desktop.

[@Humble_Electronic_Musician]

Beautiful!

[@mobypixel]

Thanks @Humble_Electronic_Musician! 🙌

[@TheFBK69]

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

[@mobypixel]

That's cool! And pretty surprising for a big name like Korg. They also made a synth/game for the Nintendo DS. I know a lot of people also like Korg Gadget on iOS, but I haven tried it.

[@Manjarow]

akai mpc also

[@System-1541]

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.

[@mobypixel]

Thanks, @System-1541! I did that when prototyping, but the female ends didn't seem to make a solid enough connection on the I2C LCD. The LCD would reset with the slightest bump. I should have used heat shrink though for sure. 😅

[@SonicVibe]

Very cool 😎

[@mobypixel]

Thanks SonicVibe!

[@nojusticeanywhere]

This is really cool! What is the black board behind the i2c LED screen? I have this screen kicking around, but not that one

[@mobypixel]

The one I bought came that way. It only requires running 4 wires. www.amazon.com/Hosyond-Display-Module-Arduino-Raspberry/dp/B0BWTFN9WF The other LCDs will work, but you might need a port extender. That's how Floyd did in his tutorial linked in the description.

[@Grimmwoldds]

The smaller board is called the "i2c backpack" As you can see, the LCD itself takes many many more pins(14 I think), and that backpack is soldered to the LCD(along the upper edge, see all those solder joints) driving those pins. So the RPi sees the backpack as an i2c device over it's 4 pin connection and sends the backpack display commands, then the backpack controls the LCD in turn.

[@peterberghoff]

9:43 With your miniDexed you can play the intro of “Michael Jackson - Man in the Mirror” with the performance 005_Aftertough from Greenhouse Bank. (A replica of the Roland D50)

[@mobypixel]

Oh cool! That’s good to know. I still have a lot to explore with it. There are a lot of familiar presets mixed in.

[@TooSlowTube]

5:30 does it need all of those buttons setting up? That seems a lot, just to navigate the menus. What do you have to press to see the patch name?

[@mobypixel]

It's not too bad. You set it up in the minidexed.ini file: github.com/probonopd/MiniDexed/blob/afa72d21aa81a9876b3f9e50f3bd6f4cd56cdac0/src/minidexed.ini#L113 The other option is navigating with a rotary encoder like Floyd Steinberg did in his video. To see the Patch Name I navigated to the performances tab and selected it. I'm not sure of a shortcut for seeing the names if you are deep in the menu stack, but you can change patches with a button press.

[@TooSlowTube]

@@mobypixel Thanks. I see two pins there for the encoder, so that would cover turning it, but nothing for the encoder button or built in switch... Is it defined as one of the other buttons? I don't really get how all those other buttons can be replaced with just an encoder, but I assume it has at least the usual built in button in the encoder to do something. I've looked at the documentation a few times but I haven't really got all that far with understanding it.

[@TooSlowTube]

@@mobypixel Okay, I've found a bit in Wiki Files, that says "ButtonPinShortcut defines the pin that is used for rotating the rotary encoder knob while the button is pressed. Probably you will want the button that is built into the rotary encoder to be used for shortcuts." I really have no idea what that's trying to say so I guess I'll just have to try it and see what happens.

[@mobypixel]

@@TooSlowTube Yeah, a the rotary encoder is an endlessly turning potentiometer that can be pressed as a momentary button. I think in MiniDexed one click selects and a double click goes back in the menu. I used one in my Teensy Synth build recently.

[@SomeRandomGuyOnYouTube]

What's the tune at 7:18 ? I recognise it but it's driving me crazy and Shazam etc. are no help

[@mobypixel]

Yeah, it does sound familiar, but it is nothing specific. Maybe it is similar to Cold As Ice by Foreigner or What A Fool Believes.

[@makato01]

Can it use the cases with a 3.5" screens ?

[@mobypixel]

I'm not sure, but MiniDexed has a forum where I saw people talking about alternative screens. github.com/probonopd/MiniDexed/discussions

[@makato01]

@@mobypixel Thanks

[@maksmakes]

Thanks for a great video! But you aren't really putting its full power to use, if you have a groovebox (or even a daw) handy that can sequence at least 8 channels of MIDI you could really put the minidexed through its paces as a 8 multitimbral synth! 🙂

[@mobypixel]

Thanks, maksmakes! Yeah, that would be a cool setup. It's kind of how Floyd used MiniDexed in his demo.

[@ToPProjectsCompilation]

Hey Nick, that's a great project. We want to feature it on our channel. Leave a reply, if this idea seems good.

[@mobypixel]

Yes, that would be great! Thanks for checking out the project and good luck with your video!

[@ToPProjectsCompilation]

@@mobypixel Hey Nick, we've published the video featuring your project. Check it out.

[@PoboyMusic]

Danger zone and Take my breath away written by the same guy.

[@mobypixel]

Oh cool! I didn't know that.

[@steffanjansenvanvuuren3257]

Which Pi?!

[@mobypixel]

It is the Raspberry Pi 3 but should work with 4 and 5.

[@mobypixel]

@@steffanjansenvanvuuren3257 oops I said the wrong board earlier. Edited the answer.

[@desktorp]

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