Roam 2 is S2 only.  It will not work on an S1 system.

Thanks for info. Think il be sending it back in that case. I'm disappointed with Sonos, as I'd only bought my amp as an ad on to my system and 6 months later, they brought out S2 app, and said my amp is not compatible with S2. I thought after the money I'd spent, Sonos products would be future proof. They offered me £30 off a new amp!

If you bought an S1 only Amp (actually the Connect:Amp) 6 months before S2, it was at least 5 years old.  The last of the S1 only devices stopped being manufactured in early 2015.  I'd double check to see if that unit is actually S2 compatible.

There is some sort of misunderstanding or misinformation. All of the products listed in your user profile are S2 compatible. The SONOS AMP is S2 compatible. Some versions of an earlier product, the CONECT:AMP, are not S2 compatible.

In any case you would need to update your system from S1 to S2 in order to accommodate the ROAM 2. Since the SONOS system software is in currently in transition, I’m not sure how successful the S1 to S2 transition will be. Other users might report their S1 to S2 system transition experience with the current SONOS software.