Apple TV sends out lots of noise over optical when woken up

Hello,

My Apple TV is connected via a DAC to a mixing desk to allow for airplay functionality over a studio setup. As soon as the airplay functionality is started from for instance an iphone, the apple tv sends out a lot of noise over the optical connection being translated to a terrible signal which isn't doing my speakers a lot of good. This is only when the Apple TV was in sleep mode when the airplay session is started. How can this be avoided?