I have a connect amp connected to two ceiling speakers. My Samsung tv is connected to an apple tv with a line-in connected to the connect amp. When I turn off the TV there is a humming sound coming out of the speakers.  How can I set up without having to go to the Sonos app and un-mute the sound? 

Hi @RDO51 

Welcome to the Sonos Community!

Sorry for the delay - as you replied to yourself, this topic wasn’t flagged up as having had no reply yet.

You can try adjusting the line-in source level as described in our Adjust Line-In settings page. There’s no correct setting - just what produces the best experience.

If that doesn’t help, you’ll probably need a ground loop isolator to remove the hum caused by voltages on the ground wire coming from the TV, such as those listed here: https://www.amazon.com/s?k=ground+loop+isolator+rca

Bear in mind you may need another cable to be able to connect the device (if the device doesn’t have it’s own, though most seem to).

I hope this helps!