Thank you a lot, it did help indeed.
So with the help of the videos I could set everything up so that the singer can hear himself, I even got the talkback working. Only problem that remains now:
When I talk to the singer he can hear me, but I cannot hear his answer, because I can’t get the signal of his mic to be heard in my control room. Is this even possible? If not how am I supposed to use Talkback properly (if I can’t hear him)?
I found a workaround using a direct output on my mixconsole and route it back to a hardware input of my audio device. Putting that into “monitor mode” lets me hear the singer… Seems a bit unnessary, given that the original signal of the singer is already connected to my audio device but I found no better solution.
So now the mic of the singer goes to Input1 of my audio device, then the singer gets his voice out over Output5 of my audio device and is externally mixed with Output 3&4 (the cue mix for the singer) for his headphone. Then I use the direct out of the channel of my external mixer which I send back into Input2 of my audio device to listen to the singer within my control room.
Any better solution?