Various Nooby Questions before I commit

Hello All,

I am thinking about building a Zynthian box as a project, but I was wonder if people could answer some questions before I jump head first.

  1. Is it possible to run Zynthian OS WITHOUT any of the hardware? I wanted to see what the OS and software was all about before I committed to building anything. However. after flashing both the “Gorgona Omega” and “Aruk” RC-2 builds and running them to a Vanilla RPI 3, all I get is a blank screen after some of the boot sequence.

  2. I was thinking about building Zynthian for a Eurorack case, are there any plans out there for that? Even if is was a 3D printed model?

  3. I know it is possible to run a Raspberry PI 3 in USB device mode, can Zynthian OS do that as well? I am mainly curious because it would be neat if it could show up as an Audio and/or MIDI device in the rest of my rig environment [macOS].

Thanks in advance.


Good !! More sounds. more wyleu food. . . . :smiley:


No. You need an audio component, It makes sounds with a USB audio card but the the latency ( time between key press/MIDI signal and sound production is really too long to make the device anything more than a test exercise.

Without a declared audio component the zynthian GUI wont start ( nothing to talk to down in the guts) There is a debate running at the moment about implementing a GUI only mode but, it’s probably something that happen after one or two other issues as we get Aruk.

There’s everything and all sorts out there. My personnel favourite at the moment is the zynth bolted to a harp that we discovered in this thread
The major considerations when mounting a zynth in an alien box is how do you mount the raspberry Pi so all the bits you want to get to are accessable. The USB & PSU/hdmi & obviously on a corner but the one that most people forget is making the case so that the SSD disk is accessible for change. It, does on occasion, get trashed ( it’s very rare and happens less frequently, in that I haven’t lost one in over a month and I do a LOT of image burning). But itf you have to take a eurorack module apart to get to the SSD this can be a bit disheartening. I’ve got an old zynthian case and it’s an issue with those which is why I tend not to develop and test on that machine.

Are you thinking of USB ON The Go? USB-OTG?
Again the latency issue will not help this mode so no real effort that I know has gone in to it.

Really the truth is if you want to do a reactive software synth you will use a ‘proper’ audio implementation for both in and out. Remember from the perspective of listening to music the delay isn’t a problem it just slows stuff up a bit, but from the aspect of a musical instrument, and that’s what we believe ourselves to be, you need as instant a response as you can get.

Go for it. Once you’ve done it you will be able to answer the questions for others and there is so much more that you will find out for yourself.

If you have a USB Audio interface available then you can configure it to use that. Plug the Zynthian into a network hub and point your browser towards http://zynthian.local/api/hw-audio and select “Generic USB”.

You can use HDMI for display. Point your browser towards http://zynthian.local/api/hw-display and select “Generic HDMI Display”

Zynthian expects four rotary encoders with four buttons. If these are not available then you can use it with a screen and mouse by pointing your browser towards http://zynthian.local/api/hw-wiring and selecting “Dummies”. The touch /mouse interface is a bit awkward in places but there are some instructions here.

It is possible to get Zynthian working with little outlay but there is a cost / effort balance - you can buy a kit that simply plugs together and provides a turnkey solution or you can read the copious postings here and bolt your own Frankenstein’s monster together. (I did the latter.)

Good luck - it is worth investing in this project. The returns are great and the community isn’t too bad… for a load of nerds!!! (And some very talented artists.)

FYI, there is a “dummy audio device” option that allows to run zynthian without any audio hardware. And you can use the audio recorder normally …

I was not thinking of USB-OTG, although interesting to learn. I was thinking of Gadget mode, where the Raspberry PI acts like a peripheral device (like a Mouse, Keyboard, or whatever). But upon second look, I may have been misinformed, or that it only applies to the Raspberry PI Zero. I am still trying to double check if that is even possible on a 3.

Specially if just want to know if it possible to communicate Audio/MIDI with Zynthian over USB or even IP if needed. But the point may be moot, if you still have to have an audio interface just to boot the basic OS.

As for eurorack, I did come across these plans almost as soon as posted, which is what basically I was looking for.

I hope that clears up what I was taking about.

AFAIK, the RBPi3 (2 & 1 too) can’t be configured as an USB device. Only bus-master role is allowed.
This is only possible with RBPi Zero …


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I think the word “dummy” should be changed to “none” or “no audio device”.
dummy is geek jargon and does not have an obvious meaning. Same thing for the no wiring option. Should say something like “no encoders”

I guess a follow up question. From what I gathered, my main question is how do you get Zynthian to completely boot without an audio device in order to set it to just use the dummy device?

The webconf is running on its own. Even if it looks like the Zynthian hasn’t been started, the webconf has started nevertheless…most of the time.