The Yamaha DX7 was released in 1983, with its FM synthesis engine completely revolutionizing the electronic music world at the time. It didn’t come cheap, and still doesn’t today, but we are blessed with emulators that can give us the same sound on a budget. In that vein, [Kevin] decided to whip up a Yamaha DX7 you can carry around in a little USB dongle.
The build centers around the use of a Raspberry Pi Zero, Zero W, or Zero 2W configured to run the MiniDEXED DX7 emulator. The Pi is then set up with a dongle adapter board that allows it to run in USB Gadget mode. The Zero line of Raspberry Pis are perfect for this use, as they draw less current and so can, under the right conditions, run off a computer’s USB port. The Pi receives MIDI commands over the USB interface, and outputs sound via a Pimoroni Audio Shim. Effectively, the result is a single-channel DX7 synth that plugs in via USB; or eight channels if you use the more powerful Zero 2W.
[Kevin] readily admits that there probably isn’t much use for a DX7 dongle, given that you could just load a DX7 emulator in your DAW of choice instead. Regardless, it’s a fun build, and one that ably demonstrates the USB Gadget mode of operation for the Raspberry Pi. Video after the break.
Man-oh-man… the PCM510x Family of DAC’s continues to deliver on these linux-type boards. I was lucky enough to work with the design team on it (and fought like crazy for features like the PLL to be used!)
A DX7 on USB is very cool too – didn’t want to steal anyone’s thunder there! :)
That’s neat. You worked at TI?
Blessed?
At first glance this makes me think it could serve as the base for an interesting voice in a modular synth setup!
just FYI, if you are into modular synths and like DX7, latest firmware of Mutable Instruments Plaits has a DX7 engine in it
Good ol’QY70 <3
I have that unit also. Thinking I’ll clean it up and re learn how to use it since it’s been well over 20 years.
The line out port is facing the worst possible direction
Try to remove the sd card. No. The usb shield has some design issues, not the audio shim.
And boy, look at the usb-c disaster to feed the thing. No usb on pinheaders was the biggest mistake of the consumer raspi family.
But on the positive side, a dx7 in compact form is a nice thing to have, be it monophonic.
By the way, MiniDexed on a Zero v1 gives a single 8-note polyphonic tone generator. Using a Zero 2 gives eight 16-note polyphonic tone generators…
Kevin
I’ve been watching this project for a while, planning on building a physical controller for it.
Thank for you for the mention, but I just did the really easy part. The real credit goes to the following:
* Rene for his amazing Circle bare metal Raspberry Pi environment and adding USB Gadget mode recently.
* Holger for the fantastic Synth_Dexed library porting the Dexed engine to microcontrollers.
* probonopd for pulling it together as MiniDexed.
* Raspberry Pi, Pimoroni, 8086 and ZeroStem for the additional hardware to allow such a neat solution.
Brilliant to hear from Dafydd in the comments here – I use PCM5102’s everywhere in my audio projects! Such great little devices :)
A full list of credits can be found on the MiniDexed page.
Yes, the solderless USB link shown in the photo isn’t ideal, but I included it as it might be easier for some. The ZeroStem gives a much nicer result and is the one I preferred in my blog, as the USB connection is at one end and the SD card and audio output is at the other.
It’s all just a bit of fun.
Kevin
In the main picture, it looks like getting audio out and powering it at the same time might be a challenge. However the software is excellent. I used it in Mairk’s track, “hey you, your tweets look pretty tonight”
It is a Pi, it runs Linux, it can emulate things.
So you can carry around nearly every computer ever made up to the PSone in your pocket.
Yeah it’s kinda a “anything you want to keep cold, Tommy Boy” kinda thing. This has been done on lower forms of board life like arduino blue pill with Mozzi but still glad to see it has somehow inspired others. Imho, the dx7 is an okay synth and an absolute nightmare to program other than fiddling around and enjoying magically found variants lol. It becomes more fun with the vector synth variants that came later from Yam.
MiniDexed isn’t running on Linux, it runs “bare metal”, I doubt that a raspberry pi would have the performance needed to run dexed on Linux.
Zynthian runs on a Pi 4 using its own Linux distro, and has Dexed as one of the synth engines.
See: https://zynthian.org/engines/_engine-list/engine-dexed
Kevin.
The issues I see is that 1) USB has been phased out in favor of USB-C cabling/ports and 2) latency due to lower USB-A’s transfer rates.
There was an MSX from 1984 or 5 that was almost a DX7 on it’s own if I remember correctly, could even play MSX games
Yamaha CX-5M, very nice machine.
I used to repair shedloads of the Yamaha MSX computer. The FM sound generator was only 4 operators.
Gives me an idea about upgrading an old keytar to DX-7…
I LIKE this idea! I have a weird comment. Can you put a Roland MC 50 mkii on a dongle? It wouldn’t need a line out. I guarantee many older MIDI guys (there’s more of us that you young whippersnappers care to admit) would buy it. Pretty much any “I hate DAWs” person would buy it.
I suspect attempting to emulate an entire hardware sequencer setup like the MC 50 would be quite a lot of work I’m afraid.
I know there are elements of Zynthian that include sequencer functionality, and I believe a newer edition of MicroDexed is aiming for a touch screen that includes a sequencer too, so those might be the nearest.
It might be possible to get Roland sounds using MT32-Pi on a dongle though…
Kevin