No sound from headphones on DDJ-RB

Ever since I had to reinstall Rekordbox, because I refreshed my mac, I can't get my headphones to work. So I looked up some possible issues and found the Master out icon as a possible troublemaker. I remember that I used to have this button and that it fixed the problem, but now I can't find the icon anymore. 

I am using a bluetooth speaker as master output, which might complicate the whole thing. Everything else seems to work just fine. (DDJ-RB)

I hope anyone can help me,

Jurgen