i´ve found a few days ago some „withdrawn from service“ 😉 Telekom (uarghh ;-( ) Media Receiver 303A->was first interested in the internal HDD->500GB Seagate, but have seen then this has also a built-in 12V/3A power-supply and its from the dimensions almost ideally as some Raspberry Pi4-ES9038Q2M-audiostreamer !! (not soo big) 😉
Display-wise its a little bit limited (due to the available space (height)) in the front, but some LCD1602 will maybe do it fine..
found then an easy way to connect some to an ESP32 via I2C and via some „web-remotes“ (see other posts here „Project-1“ etc..) we can select via some photocoupler/relais the inputs of the ES9038Q2M (Coax,Toslink, I2S/USB), adjust the hardware-volume, filter-selection and so on and can display the settings on the display/LCD1602) !!
so far so fine, but this is a heck of a lot work to do !! 😉 ..
(i´ve planned to use Volumio on the raspberry ->easy controlling via the web-interface, DLNA-capable, MPD etc..)..
as said, here at first testing-out some aspects/parts for it and a first result by example is that these 3A makes the „blue“ ES9038Q2M absolutely a little bit „airy(ier); had before some 2A power supply (12V)..
by that the „Leaf-XMOS-USB-bridge“ (->http://essabre-90xx-rpi.sfb2.com/?p=2066) is better than first thought..
+ also my new „ESP32“ will come to a new life 😉 (not to mention the Raspberry Pi4 2GB)
makes really a lot of fun here, and i will inform you about some further improvements !!
greets for now !! 😉