Hi Rolf. Nice set up! I have made a Zynth similar to yours (slightly smaller screen) and with a Hifiberry DAC/ADC.
I wonder what your thoughts are for using the cooling fan once you fit the soundcard? With my setup there is very little space between the main processor and the soundcard HAT - definiteyl not enough to fit the fan in. It seems to run ok with just a small heatsink stuck on the processor, but I don’t have it in a box yet, so there’s still plenty of airflow around it.
Hallo scro 
The processor and the surrounding area get very hot in the case. To protect the components, I ordered this fan hat:
I can then mount the HIFIberry over it with 2x20 Stacking Header. Encoders and buttons will be added later in my case.
Greetings Rolf
This is my different Synth Project “Jeannie” its based on an Teensy 4.1 board.
Prototyp
Case
My blog: PJRC (Teensy) Forum
Greetings. Rolf
I applied a 20KHz test tone to the Audio DAC (HIFI Berry DAC + light) of Zynthian. Looks very clean and good.
and this is the noise floor from my Zynthian
Hallo friends…
I now have an Argon fan installed. To activate it I had to install a script (3nd photo). I installed the script with the help of the terminal function off Zynthian webpage. It works wonderfully with Zynthian. When I switch on the power, the fan runs at 50% for a short time, then it switches off. If the temperature rises above 55 °C, the fan goes to 10% and is pleasantly quiet. The fan switches off at 45 °C.
Greetings Rolf
Oh no
Zynthian does not play any sound over Midi IN. I will uninstall the Argon Script and rebuild the Argon Fan Hat for fans on GPIO 14. That works fine without any problems.
I dismantled the Argon Fan Hat and restarted Zynthian. Midi In works again. I installed the Argon Fan Hat again and installed the Argon Script. Then I did a Zynthian update on the Zynthian webpage. Now Midi IN and Argon Fan Hat work together. I hope… 
Greetings. Rolf
It is never easy with extra GPIO wiring and occupied pins. But nothing is unsolvable in zynthian, specially for stubborn people and with help of our friendly forum ! Good luck ! And please share the solution with us.
Yes, it can be a little bit of a dance to convince yourself that what you build actually does work ! 
How hot are things actually running? webconf does report a temperature.
Do the switch on if the fan agree with the zynth temperature?
Yes it is a very good forum 
My Result written in my last post before.
Midi IN (RxD) and Midi Out (TxD) is not used by Argon Fan Hat.
Greetings Rolf
Yes, the switching temperature is the same.
At 55 °C switch fan (10%) on and 45 °C is fan switch off.
I wouldn’t do that cause all these fakes have very bad press these days and there’s only one true Zynthian 
Background images can support a nice GUI design
Looks like you Quantum has a migraine!
I got my self a UPerfect 7" capacitive screen:
and a HIFIBerry DAC+ ADC:
Higher resolution than the official screen.
It’s almost the size of a small tablet. Is the 1024 x 600 pixel resolution a problem for the Zynthian?
