The Zynthian is a great, community driven, open Synthesiser platform. Read all about it here : https://zynthian.org/ I wanted to build one for some time now, and so I collected some stuff in the past few years that could be useful. But I never actually checked if it could all come together, but now is the moment.
This project will be based on parts I already have. Some of it was bought more than two years ago, so it may not even be available anymore.
After downloading the latest image of the Zynthian OS and writing it to the SD card (Details are here: https://wiki.zynthian.org/index.php/Zynthian_Software ), it is time to start it up. As the Zynthian website warns: this image is pre configured for use with the official Zynthian kits, so if you want to use it in different setup, first go to the web-interface to configure it.
But that's a bit of a problem when using a RPi3A+. I cannot connect it throug an ethernet cable as suggested, and it will not automatially connect to my wireless network, since the WiFi parameters are not set. (according to the guide you can set these through the interface. Which I do not have yet)
To solve this, find the file 'zynthianos-wpa-supplicant.txt' which is in the root of the SD card. Here you can add the wifi settings for your network. Make sure the 'country parameter is also set correct.