I built a zynthian a couple years ago but I recently pulled the Pi for a different project. I’m probably not going to go back to it so I am trying to sell the box I made.
7” touch screen. Ribbon cable is a little wonky. Sometimes screen gets slight red distortion but you can get a new one for $10.
Behringer UCA222 for audio i/o
A hacked turtle beach midi cable for midi I/o
Drop a RPi 4 in and you’re good to go. Make me an offer