To be clear, I meant for my own use case. I would connect a Chromecast Audio to one of the following:
https://www.minidsp.com/products/dirac-series/product-line-summary
https://www.minidsp.com/products/dirac-series/ddrc-24
Isn‘t the 2x4 HD the same as the DDRC-24, without the Dirac sofware?
They don‘t measure as well as the SHD, but some members would say the difference is inaudible.
Your use case is more complex than mine - not sure if I understand it fully, if I’m honest. So, I’m not suggesting you follow my advice. Just giving my opinion on streaming options.
You could connect a CCA to the SHD if you don’t like Volumio.
BTW, I’m assuming the optical output of the CCA will work ok with the optical input of these units. I’m sure someone will correct me if I’m wrong.
Also, my opinions on Volumio are based on my own use case. Some people like it. You should check out their forum, or better still get a cheap Raspberry Pi and try it out.