Zynthbox, a new project based on Zynthian

Hello Zynthians,

I’m happy to announce there is a new project based on zynthian, that has the goal of spreading the reach of Zynthian by demonstrating how well Zynthian is suitable not only as a synth platform as is, but also as an open-source base for expanding ideas and try new things on it:

Introducing “Zynthbox”, an open modular workstation concept in form of a custom img for rpi4, based on the original zynthianos.

Zynthbox uses Zynthian for all underlying sound and synth engine handling, then adds a customizable modular layer UI on top that simulates a minimal workstation concept for rapid sketch / song building. This said, the target form factor is different than Zynthian, where is recommended you connect a 7 inch screen to it. Also, it is focused on quick sketch capturing ideas, so at at some point you will likely need to export the audio and continue in a DAW, if you care for absolute full on production. For anything less, our aim is to make the software sufficiently useful.

Please note that the first boot takes quite a while as the system expands the available space automatically to the sd cards limit.
After that, any subsequent booting should be faster, depending on the sdcard in use.

Here are some more details at this stage:
The project is currently in an early alpha stage, which means it is not every day production ready and we are still in an “ideas testing” phase, which may or may not what you like, as it also means you may be interested in giving feedback that may influence how the first version 1.0 stable might look like. At this point almost all of the sound functionality comes from zynthian, albeit presented and made accesible in a different way, following more a “minimal workstation” concept that focus on quickly capturing sketches for then later export and full production in a daw.
Some of the functionality zynthbox provides:

  • a Session overview, where you see 12 Tracks, clip cells and an early stage mixer
  • allows recording, looping and playback of up to 12 Tracks pt.I or II (=24 clip cells), 5 of which could be midi connected
  • recording of audio clips, where any sound information used during the recording gets stored as part of the wav file for later restoring and sharing with others
  • minimal sequencer, which allows programming of 5 midi patterns with up to 8 bars x16 steps (currently no freeflow piano roll recording yet)
  • sound combinator: easily assigning and combining up to 5 synths layers to any of the 12 Tracks
  • saving and loading these multi-layered sounds, incl. fx, pitch and keysplit information (shareable)
  • Editing synths: re-arranging parameters of synths / fx plugins freely and allowing to theme them on a per plugin base ( shareable)
  • a super-early stage arranger page (not usable as is)
  • some more started, but not ready subpages

So zynthbox is all about expanding zynthians capabilities to cater to a different goal, therefore not replacing, but adding to the zynthian concept to possibly attract more people to become aware of zynthian, while sharing the underlying technology and resource stack (LV2 plugins, engines, presets, control parameter mappings), and the zynthbox modular extensions. There are plans to also directly collaborate with the zynthian developers to help zynthian get a better, more fully usable API, so any UI project, including zynthbox is able to make use of it.

This alpha version is provided as is: It should be basically usable, but contains still quite some bugs and unpolished areas, like missing functionality or unconnected dots. On the positive side, this early state allows any one who likes the concept and wants to help make it better to join in that early. So anyone is more than welcome to post any comments here or leave report bugs on github or post suggestions of ideas or proposals here or at github. Our goal is to reach a 1.0 stable version by summer 2022.

Mid to longterm, there will also will be a collaboration looking for a possible fully open hardware concept, but that is for another post sometime in the future.

Prerequisites are

  • a rpi4
  • 7 inch screen with 1024x600 resolution (it could run on lower res, but then there will be issues)
  • microsdcard 16gb

So if you like to get involved with early alpha testing, give it a try:

Our github is here:

We surely love to hear your feedback!

EDIT: Adding some screenshots:

Session View, Mixer:


Main Menu:

PS: The midihub is not part of default, it was used to demo that people with such a hub from blokas could run the configurator on the box too (I have one :wink: )
And yes, that “norns testing” module is kind of working within zynthbox after install (it is an extra module), here are some errata:

  • right after install, there is no sound, needs a zynthbox to reboot once to work
  • Close button only works with the main window (not norns black window) active, otherwise use “EXIT”
  • the window position is yet not perfect, has kind of a mind on its own (that was one of the harder things to make work outside of the norns hardware)
  • if you see the fireworks, but it seems stuck, check if you got a usb midi device connected… detach it for a second or two, then re-attached again, as norns continue to then work normally

If you want to know more about that or help, just ask :slight_smile:


Sounds interesting. Any screenshots or vids to demo? Inquiring minds would like to know.


I’ve just installed it and it looks really interesting. Thanks for creating this!

Like you said it’s still buggy (sometimes the UI hangs, needing a reboot), but the main issue I have is that the master fader in the mixer is all the way down and I can’t move it.

The other faders react fine and when I do the audio test found in Settings I do get sound from my output.

Any ideas?

Lonely Crab

Hi lonely-crab,

thanks for the feedback and testing!
Do you have any soundcard connected to the rpi or only use the headphones out?
Does picking any synths for e.g. Track 1 allow you to play and hear sound?

Hi pac_71, I will post some current ones in the original comment, as things change rather fast in this stage, screenshots could get outdated quickly :wink:

Edit: added


Can you please let us know your audio configuration. It will be of great help to know what sound card you are using, Rpi Headphones or something else is selected?

We noted down the issue and will try getting a fix for the same.

Thanks for reporting.

I use a HifiBerry DAC+ (and configured it in Zyntian settings) and RBpi headphone setting is off.

Don’t remember what I did exactly, but in Playground I can get some sound out of track 7, now.

I’m not sure if this is a known issue, but I found another thing.

The sequencer screen (like shown your screenshot above) doesn’t fit on my display: I only see parts of tracks 7 to 11 and I can’t scroll to see the rest.

I use the official Pi 7" 800x480 screen.

Yes, this is known for screens with less than 1024x600 resolution.
Will add that minimum resolution info, so maybe with less we can get scrolling or minimizing elements to work better.

1 Like

It seems reasonable to declare a minimum or optimal or only resolution at which an application works. I know we expect everything to adapt to whatever screen we are using but maybe some applications are designed to work on specific hardware. Zynthian tries hard to work at different resolutions on different screens but Zynthbox is a different thing. Of course Zynthbox users QT which has the ability to adapt so maybe it could handle different configurations - but let’s see it develop first to be more feature rich, stable and efficient.

The rest of the interface works quite well on my display, I think. If you could manage to somehow fit the sequencer window on it, that would be great.

(It may even be a viable minimum resolution in the future, depending on how well this can work)

Hey there! One of them people what do work on the thing here :wink: Entirely correct, what you spotted there was a little error that’d snuck in, and it’s indeed supposed to fit (if perhaps not perfectly, but it should be able to squeeze down in side a fair bit even if the controls will end up really tiny and a bit awkward at times). i’ve fixed it (actually did so last week), and next time we roll an update for it, the pattern popup should fit on your display. Simple problem ,and simple fix, too — i do like those :wink: Plenty of other stuff coming up as well, of course, but thought i’d mention that i’d fixed the thing you commented on specifically :slight_smile:

Also just checking in in general here to say that i really look forward to seeing what people do with this thing. Realising that i’m sat on the inside of the project and whatnot, but i look at what we got and see a whole lot of potential that i, as an absolute musical plebian, have no chance of making proper use of, meaning i have to look to those with the skills to use it. Properly excited to see (or hear, i guess :wink: ) what people do!


Debian derivative? :wink:


I’ll check it out and let you know.

Just plopped this onto a spare sd card and started to have a play. I’m liking the feel of it so far, though I have a 800x480 screen rather than the recommended res.

When you “test audio” how do you then get it to stop? Am I missing the button off the side of my too-small screen?

1 Like

Hi scro and thanks for testing!

The audio function has no button yet, so its a bit weird. Now that you mention it, we will add one and adjust it a little with next update.

800x480 would make the touch elements a bit small, and (like a squeezed website) could introduce some weird overlaps or bad resizes here and there. With our next update, it could be more usable though due to some added keymaps when you have a keyboard attached. We will announce the new update shortly, you them can simply use the internal update function without reinstalling.


I installed Zynthbox (build 2022-02-16_1350) on a Raspberry Pi with HDMI display. Most of things went well except:

  1. VNC doesnt work, neither using zynthian config page nor using VNC software
  2. USB keyboard is erratical, especially on module installation page where I cannot move the selector down (it keeps going up).

I couldnt install Norns addon module, and does it work on zynthian or this bare raspberry config?

Agreed with this one.

Does anyone know if I cant install extra modules (namely Norns) using GUI (keyboard is unusable and mouse doesnt work at all), is there a way to do it using terminal?

Hi vlaad3,

thanks for testing alpha.

Does the attached hdmi screen has touch?

We are in the process of preparing a new img beta, which will be much more optimized, but that might take another 2 weeks or longer before the release. Meanwhile we can see if to fix any issue, so if we know your system (which screen, size), you could likely update and it is fixed. I personally never used a mouse with alpha, and beta has quite some things updated, so we cant update and mix with current state, so either we find+ fix that alpha issue or you wait for new beta img.