Woaooooo Rod!! Your Zynthian is a f***g killer-monster!! Congratulations!!
I suposse you will be using a lot the MIDI learning subsystem with your extra “Arduino MIDI Controller”. Keep me informed of the problems you find, please …
It is a simple preamplifier, using an TL072 and a BC548 forthe peak indicator.
I put a trimpot in the circuit to control the total gain of the circuit, but i believe that it is still possible to improve this schematic.
I made the drawings using Eagle (Autodesk), you can find the files here.
I’m also using a separate power supply for the audio pcbs. In the first tests, when i used the same source as raspberry, had a lot of noise in the audio signal.
I’m still planning to mount two buffers for the outputs. One with P10 plugs output, with gnd line isolation and another balanced with audio transformers and a ground / lift switch.
About using the MODUI with the MIDI controller, i only noticed a small problem when I use the select button to browse the existing plugins in the MODUI pedalboard. Plugins are switched on when the selection button is used to navigate.
Presumably one could cut the track from pin 1 (5V) on the 40 way and feed the on-board AMS1117 from your separate supply or a DC to DC converter as per the Power Supply.
Anyone Put a scope across the +5V on a Pi/Audio Injector? Kind of . . . .
Thank you, Team Zynthian for making it possible !
Beautiful thing with amazing possibilities !
My current prototype is complete, everything is working great for now. Some things are in “todo” list, and I will to it step by step. The case in temporal, would make something wooden for the permanent solution.
Todo list:
Midi leds
New case with interchangable back plate for configuration change options and an option to remove an sd card from below without opening the whole case.
Test input and midi
Current configuration is:
Rpi3 B+ (2017)
Audioinjector stereo
Samsung EVO 32Gb micro sd
@jofemodo, it is a real pleasure so solder everything and make it work - thanks to you ! Looking forward for complete sooperlooper integration, then audio input would be used properly. As for now, will try it with my open theremin and maybe post a video.
The only bitter part, that while assembling my ozmaker piscreen 2 stopped working with touch. Trying to resolve the issue (and I don’t depend on it much, knobs are enough in most of cases) because having some features that doesn’t work is unsatisfying.
May be I have bent the screen a little with the screws, when I first put it into the case. At the beginning touch worked out of the box.
Also, my zynthian is one of the first in Russia (like @Schpion’s with great case). Happy to extend the zynthian map a bit !