using Sonos products with existing amplifier

You can use the Sonos speakers to replace your stereo's speakers. You can replace your Denon's AM/FM tuner with Sonos' TuneIn service, which covers most radio stations that have online streams available.

As far as your CD Player, you'll need a Sonos device with a stereo Line In connection to hook it up to. The Sonos devices with a Line In connection are the Sonos Connect or Connect:AMP, as well as a Play:5 speaker. The Connect or Play:5 would likely be your best options for this... unless you have a pair of wired outdoor speakers that you might want to hook up to a Connect:AMP.
So, back to my situation.  If all of my devices (except the TV) route through the receiver and the output source can be selected at that point, all audio output would travel by RCA cable from the Line Out on the receiver to the Line In on the Sonos Connect.  From the Connect, sound would travel wirelessly to all Sonos speakers anywhere in the house where they would be controlled by the app on a tablet or phone.  Do I have that much correct?  The TV could connect by a digital input cable to a Sonos Playbar, which would then be able to wirelessly distribute the sound to other Sonos speakers that you select on the app.  Is that part correct, too?  Thanks.

You can use the Sonos speakers to replace your stereo's speakers. You can replace your Denon's AM/FM tuner with Sonos' TuneIn service, which covers most radio stations that have online streams available.

As far as your CD Player, you'll need a Sonos device with a stereo Line In connection to hook it up to. The Sonos devices with a Line In connection are the Sonos Connect or Connect:AMP, as well as a Play:5 speaker. The Connect or Play:5 would likely be your best options for this... unless you have a pair of wired outdoor speakers that you might want to hook up to a Connect:AMP.
Apologies William... I completely missed that you had asked a question so long ago.

Yes, you have both of those points right. If you still desire to use a receiver with multiple sources to feed into Sonos, then there's no problem. Plus you can hook a TV up to a Playbar, then group in other speakers to have TV sound play throughout.

But if you were to subscribe to a music service (or transfer your CDs and/or other media onto your computer) and use internet radio services like TuneIn or iHeartRadio for your local stations, then you could even eliminate the need for the receiver and the additional Sonos component (not that I want to take away from sales of their products, but I would think you'd be more interested in saving money). Plus you would gain additional control by being able to change radio stations, albums/artists/songs, etc. all from a smartphone or tablet, rather than having to go to the receiver to make a change every time.

Hi,
I realize that this thread is a year old, but I don't think the OP concern was ever properly addressed. Either that, or I don't understand it.

In looking at the Connect, there isn't an Input, only outputs. It looks like the only way to get information into a Sonus system is through the router, and that would require a network attached device. Is it possible for newer receivers to stream their sources back into the router ? I don't think so.

In looking at the Connect, there isn't an Input, only outputs..
Incorrect. It has RCA L/R Line-In jacks.

Then that's good news. Thanks. As I look more closely at an image I can see that.

I just got a connect and a play 5 today and it was a bit of a fiddle, but yes, my old analogue amp now connects to the Connect which outputs to my play 5. CD and Turntable connected to my amp, works a treat, sounds great!

Gr8!