Hello again,
if i say: >I hate Linux < it means ironic… 
I am not an Linux Guru. If errormessages comes up i am at the end of my knowledge.
Last night i try it by hand to install the hifiberry drivers as @steveb suggest it…
I think the driver is working…
… and there is an Audio capture device…
I GOT IT! 
I edit the /home/pi/zynthian-webconf/lib/audio_config_handler.py file and insert all the stuff
for the dac+adc card.
audio_config_handler.py (9.9 KB)
It takes 2 hours before i understand that i must write “analogue” instead of “capture”…
But now it works and everything is fine for me.
Sometimes i hate Linux
Thanks for the comments. It helps.
Best: Dirk