I took a closer look at the Katana:Go and also tested it successfully with the computer as an audio interface. I can listen to music and use it alone in Studio One only under Windows Audio, but not as a separate Katana:G audio interface.
But the Katana:Go can only handle 48kHz and 16bit, can MG3 handle that at all at the moment?
A combination of Zoom R16 for MG3 and together with Karana:Go under Windows Audio in Studio One did not work either.
Both interfaces you are using are a sort of āspecialā. Have you tried to use Cubase LE, that came with the Zoom R16, as DAW just to check if a combination of both interfaces plus LoopMIDI is working at all?
As far as I can see now that probably USB conform is not the most important thing, but the multi-client feature of the audio interface to run the workaround with LoopMidi in Studio One currently is.
Maybe Iāll buy a new audio interface at some point, as the Zoom R16 is already over 10 years old.
Iāll wait and see what @JamO achieves with the developers of Studio One. And how MG3 continues to develop, also with regard to the compatibility of different audio interfaces.
Thanks again to @Dutti and everyone else who has tried to help me.
In this case I think, that You wonāt regret it, if You buy anything from RME. In principle I am just another idiot trying to cope with the complexities of DAW & Co, but these are really good. You can even reach the people of RME by phone (hope that didnāt changeā¦).
Iāve never run a machine with a class compliant interface and an ASIO interface thoughā¦And of course: 2 ASIO Interfaces on one Windows machine donāt workā¦.