Just for sharing with the samplerbox community.
Googling on the internet I've found this interesting soundcard https://blokas.io/
What is interesting is the SPI IO & OUT midi interface and the 192khz 24bit 6.35mm audio jack for input-output sampling (with gain controls).
Someone in their forum has succesfully built samplerbox:
https://community.blokas.io/t/using-pisound-to-do-a-samplerbox/206/10
I've no relations with this project, but it looks a very good solution for musicians. The only missing part is the display, but it could be possible to add this feature using the extension header.