Astro A40 connected with Macbook Air and PS4

Hey Guys, I bought today a Macbook Air and my Astro A40 2013 sound is cracking on the Macbook. My optical Cable is connected to the PS4 and the USB Cable to my Macbook air. The Sound which is coming from the Macbook starts every 10 minutes to crack. Could anyone explain how to properly connect the Mixamp with the PS4 and my Macbook Air? Thank you and have a nice day.

BTW I'm from Germany, sorry for bad Grammer!