Hi Sterling, thanks for the reply and the links.
On the page of Airplay 2-compatible products from third-party vendors, I don't see a specific category for devices that I've heard referred to elsewhere as "endpoints" -- i.e. devices that receive streaming music and convey it to an amplifier/speakers. However, when I browsed the list of Airplay 2-compatible receivers, I noticed that one of the products listed, the Bluesound Node 2i, sounds like it fits the definition of an endpoint unit.
I'd be very interested in finding any similar products from other vendors in order to compare features and costs. However, I don't need a full-up "receiver" per se -- I don't need it to include an amp or any other receiver functions, just an interface between Airplay 2 and my existing stereo amps. The list of Airplay 2-compatible receivers is pretty lengthy -- besides going through it product by product to find ones similar to what I'm looking for, do you know of any way to sort out the kind of unit I'm looking for?
Also, I have one other question. I've heard that it's fairly popular to use inexpensive Raspberry Pi's to act as endpoints for amp/speaker stereo systems. Unfortunately, I haven't found any software for the Raspberry Pi's that is billed as being Airplay 2 compatible. Do you know if Airplay 2 is compatible with any software for the Raspberry Pi's, or any similar very small, inexpensive systems?