Yes - the Sonos Ports line-in audio can be played to any/every Sonos product in the same Sonos system around the Home, up to 32 products in total.

I can’t get it to send a signal. It goes from the pre-amp out (line out) to the line in on the port. 

You must Group Rooms with PORT.

Thanks to both, I will re-try.

Hi @Robjohnlong 

Welcome to the Sonos Community!

Grouping rooms with Port will only work if Port itself is playing it’s own Line-In feed.

Instead, choose the Port’s Line In from the Home Screen, when the other room(s) are selected in the app.

I hope this helps.