Old amp to Port to ERA300

Got it.

Beeped a few times but that's all. No connection. 

What sort of connection do you have from Amp to Port?

Are there any sources besides CDs that you want to play? 

Edit: I am wondering if a better set up for you would be CD into Port and Porr into amp.

 Is the amp line out a variable preamp out?  I have a Port, but nothing is connected to it.  So the Line-In settings are grayed out.  I don’t know if Line In would show on the Sonos app Home Screen when the Port is selected as the device

to play to.  If Line-In does show on the Home Screen select it or I guess Autoplay would do that for you when the port detects a signal from the amp.  All guesswork on my part.  Other Port owners can clarify.

 If you get an indication that the Port is playing something you can group the Port with the 300.  Like ​@AjTrek1 stated though there may be a delay between the wired speakers and the 300.

If the CD player is the only amplifier source, connect the CD player to PORT’s Line-In and PORT’s Line-Out to any amplifier input except Phono.

Line-In is simply a music source on the network that can be selected to play on any combination of SONOS players. On PORT you could select its Line-In to play CD through the amplifier or any music source available to the SONOS system.

​@GreyGuy . If you stick to the configuration that you ate currently trying to make work then the Port is just a (very expensive)  means of getting audio from CDs to your Era 300. If,instead, you make the Port an INPUT to the amp  you  in effect turn your amp and speakers into another Sonos "room". Anything that you can play on the Era300 could be played on your amp and speakers.  That would include CDs, if you connect the CD player to the line in on the Port. 

I just got off the phone with technical support. They eventually concluded I could not use the Port to transmit from my old amplifier to the Sonos speaker! Said that was not what the Port does.

Which seems to contradict the (limited) info on sonos. com. I'm not happy. 

Any other suggestions? 

Thanks! 

What is the Harmon Kardon model number? 

Never mind--I figured it out. 

The Port is in the Den.

So, in the app: Den → Line-in (connected) → Autoplay → Autoplay Room: checked Den. And, in Autoplay, turned on Include Grouped Rooms.

Obviously tech support didn’t know what they were doing. And it takes a good bit of digging on Sonos.com to find all these details. 

Anyway, I’m finally set up and all works well. And sounds great.

Thanks for all the suggestions along the way.