I would like to play my music from Spotify on my AV receiver (Pioneer VSX 529) without z.b. To connect the smartphone or the laptop to the same. Is this project feasible with the Chromecast?
If you have the Chromecast Audio, you can. But keep in mind that you only get 256kbps over the Chromecast. Sounds accordingly so not so good (even 320kbit is not great, but that's another matter).