Seemlessly switching different streaming sources

Hi all!

I want to build the following (audio) setup in my home: My phone/tablet should act as a "remote"; then I would like to have one (or more) streamer(s) that is controlled by the remote and plays Spotify, SoundCloud, YouTube and Netflix. For example raspberry pi for Spotify and SmartTV for YouTube (if you know any streamers that can do all three and that have digital outputs, please let me know).

These streamers should then go into a DAC which in turn should be connected to some hifi setup.

Now I would like to have it such that the audio is switched seemlessly. That means that I don't have to manually switch from YouTube input to Spotify input for instance. Whatever is playing should be played on the hifi boxes. If multiple sources are playing then there should be a priority list.

The device should be either between he streamers and the dac or should be streamer that does it all. Do you have any ideas about this? I heard about the Echo Link, but I'd prefer to use my own DAC.

Let me know if you have any ideas! Thanks 

I got this,..

Here's the thing if you don't mind differing levels of fidelity this is easy. For example my streamer, an old Auralic Aries Mini, can do Spotify/Tidal/Qobuz/Amazon a few other streaming services, internet radio, plays local files. But it's also a Bluetooth and Airplay enabled device, so using those formats any BT or AP device can cast to it pretty simple.