Thanks for the question. Did you have specific questions about the SA-5? It will work via Play All with your other SoundTouch systems, provided they are all on the same SoundTouch account.
As well, Airplay 2 is not yet available. We do anticipate that it will be available for select SoundTouch systems in the near future. For future updates, please follow THIS thread.
Please let us know if you have any other questions.
Brandon - Community Support
Thx for your answer, the thread confirms that Airplay 2 will be supported for selected ST systems. But before I purchase an SA-5 system, I would like to know if the amplifier is one of these selected ST systems? Hope you can clarify,
May 19, 2018