Apple TV has hijacked my sound output

I use a Scarlett 212 interface for audio input and output on my 2008 iMac. Since I used apple TV and airplay in my home with a Macbook and iPad, my iMac preferences will not show the Scarlett for an output and there opens;'t seems to be a way to get airplay/apple TV out of the preferences either. I've reset everything I can.

It's particularly annoying distance i can't make my garage band recordings now because there is no output to my monitor speakers.