"What are you using the capture card for? It sounds like you should put the capture card in the streaming computer, since it would be capturing the video from your gaming computer. You won't be able to use a Blue Yeti with a mixing board. It plugs directly into your computer, and for this setup, that would be your streaming computer. You could use a line-in audio cable out of your gaming PC and run it into your streaming PC, to capture audio that way. If you already have a mixing board for whatever reason, plug your audio cables coming out of your gaming PC into the mixing board, then run a line out of the board (depends on the board, but you could probably use the Headphone out jack or the Main Out jack) and run that into your soundcard on the PC. Or you could just create a streaming server like this: https://obsproject.com/forum..." - Sam Houston