MiniDexed FM Synth

This looks VERY promising:

MiniDexed - Eight concurrent DX7 instances (based on Dexed) running on a Raspberry PI with a basic display.

Once Raspberry Pi prices come down to something reasonable again I’ll surely give it a try …


I loved my TX816 but eventually replaced it with an EssenceFM. I thought nothing could match the crunch of those huge TF1 blades, but was really surprised how much of its sound just came down to layering (which the EFM does much, much better).

This definitely looks worth checking out if you want to explore that sound (and prefer something dedicated over stacked tracks in a DAW).


This looks cool, but I do wonder, what’s the difference between this tiny computer emulating a DX7, and a laptop with a MIDI controller running a DX7 VST?

It really seems like a semantic difference more then anything else

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No difference. It literally is a computer with a midi controller running DX7 VSTs.

One advantage of this, though is it has the potential to be put into a preconfigured box with custom controls that don’t require setup/configuration/screen/mouse etc. because it’s running on a tiny embedded platform. So you could use this as the heart of a packaged up stand-alone device where it’s hard to do that with a laptop/DAW.

Korg Opsix, for example, runs off of this same type of embedded computer. Of course, instead of running Dexed VSTs the Korg has a variation of the Opsix Native VST at its heart, but same principle. I don’t think any of us would do something with that level of fit and finish, for sure. But putting this and a controller in a tiny enclosure could get you most of the way there, and have a completely different feel from DAWing around.


This is cool, i wonder if the “host/minios” part of it is available for use as a platform for other synths, that would be sick

The project uses as its base, an open source project to provide bare-metal access to the Raspberry Pi platform without an full operating system required. Guess this could be a platform for other stuff.

Moving Dexed there was a good candidate as Dexed is open source as well.

Awesome, big thanks for the info :slight_smile:

The biggest difference is going to be in latency. Without an OS, there is very little between the synth and the hardware. Dexed or any other soft synth on this platform will “feel” like hardware.

Definitely a fun hacker toy, very useful for multimedia installations, and likely to be a centerpiece of a big DIY community.

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And for me some key differences are:

  • Portability - this is about the the size of a pack of cigarettes and I can easily power this from the same battery pack powering my Digitakt

  • Creativity - I really enjoy working dawless, spent so much time on a computer screen already at work and working within the limits of a small hardware environment really speeds things up - less options = faster workflow (at least for me)

  • Focus - this little box does exactly one task - even with a small computer inside (like in all our Elektron devices :slightly_smiling_face:) this feels much more like a piece of hardware than a window in my DAW.

By the way, I was just too curious to wait for prices to come down :innocent: and got myself a Raspberry Pi 4 yesterday with 2 GB (RAM is no bottleneck for this app),. Due to chip shortage they are either completely overpriced or not available at all but I was lucky to get a used one in my neighborhood for 50 € …

MiniDexed was up and running in 15 minutes - 8 tracks of multi-timbral and polyphonic Midi from the Digitakt to the box working fine, no hiccups . I have not received the display yet, but setting bank and program at the track level work fine. Same for parameter locks with in-track program changes.

Initial audio quality from the Pi’s on-board stereo jack relatively poor and distorted as expected and documented in the project - but I have already ordered the additional audio board with a dedicated DAC tomorrow from Amazon, should arrive tomorrow. This plus the display and rotary encoder add another 20 € - not too much in total for a very fun project so far.


Is this required to be a specific board? Or would hifiberry work?

Some info on the supported audio chipsets is on GitHub and in the YouTube video’s description.

I ordered the “Raspiaudio+ V2” which was linked in the video from Amazon (, but as far as I understand this is simply a hifiberry clone with the same chipset.

Found out there is actually already another project using the same “bare-metal” platform emulating a Roland MT-32: Let's compare MT-32 and PI-Midi MT-32 emulation - YouTube

Not exactly a device I miss but show the flexibility of the approach …

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Awesome :smiley:

Received the Raspiaudio+ V2 DAC today - now MiniDexed sounds really great, no noise or distortion, latency is excellent, too.

The developer just added Midi CC control of pan, filter cutoff/resonance and fine-tuning on my request. Tried some patches with 8 stacked voices and pan and/or tuning modulated with my Digitakt’s Midi LFOs, very sweet.