You state: “Unable to make this combination connect and play.” Where does it go wrong for you? What do you want to achieve?

The two apps you mention are related to the two versions of the Sonos operating systems S1 (white app) and S2 (brown app). To be able to group the Connect with the Play:1 both devices need to be on the same software version. The Play 1 can work on both S1 and S2, for the Connect it depends on the year of production of the Connect. Before ca 2016 the Connect is S1 only, after that it is both S1 and S2 capable. If you need to downgrade, here's how you do this: https://support.sonos.com/en-us/article/downgrade-a-sonos-product-from-s2-to-s1

Thank you. How do I determine the year of mfg.?

My need is to be able to play the various sources: FM, Internet radio, Spotify, etc., to play to the Play:1 speakers, from the receiver, via wi-fi.  This is for background music in a soup kitchen with the receiver in the kitchen and the speakers on the serving floor. Various people will be responsible for selecting the source, on different days, so use of the app on a phone to control the sources is not viable. It is NOT possible to get hard wiring to the speakers. The router is centrally located.

As to “where it went wrong,” I received various messages about compatibility between the various components and the two apps. Felt it best to consult with the experts before proceeding.

The connect will work with your receiver, either connect its output to a line in on the receiver or connect it to the tape monitor jacks.

Your problem is not that connection but in assembling the various Sonos into a system, Go back and look at the link 106rallye posted above and first get all on the same software S1 or S2. You can decide that, as said above, by checking the version of your Connect. If possible go with the S2 software as it is the preferred version for hardware that can use it.

Once are all on the same version follow the usual setup steps.

I’d install one of the Play 3s first: 

https://support.sonos.com/en-us/article/set-up-your-sonos-play-3

Then add the others as the last part of that page describes.

Last add (at the end of the page, not set up new) the Connect:

https://support.sonos.com/en-us/article/set-up-your-sonos-connect

Once set up go to the Connect’s room (you pick the room names during setup) and group the Play 3s rooms with it.

Bravo! Followed the above recommendations and I am live. Turns out my “Connect” only supports software S1. 

Now that I have sound through the Play:1 speaker from the Onkyo receiver, I need help with volume control. 

The RCA cable is connected to “line out” on the receiver and “Audio line in” on the Connect.

A pair of speakers, NOT Sonos, are connected to the receiver speaker outputs for music near the receiver in the kitchen.

The receiver controls the volume on the NON Sonos speakers.

The volume for the Sonos speaker is ONLY controlled by the volume control on the Sonos.

The Sonos speakers now only one but eventually 3]  will be mounted high on the wall, to prevent theft.

How do I set the system so that the receiver volume control will control ALL speakers? Sync of sound is not an issue since the speakers are in different rooms.

Hi @RamseyD 

Welcome to the Sonos Community!

I’m not sure that’s possible, but I did find these instructions that I think relate more to having Connect as a source for the Onkyo, rather than the other way round, as you have it set up.

I hope this helps - if not, I can only refer you to the Onkyo manual or to their technical support.