For AmazonHD There's the Echo Link.
https://www.amazon.com/Echo-Link-Stream-stereo-system/dp/B0798DVZCY
Or one of the small I5 fanless PC with Windows. Windows OS has the RemotePC app built in so you can control it from your laptop, Tablet or phone. I liked it better than the Link because I can also run Foobar to play stored music.
For non AmazonHD users the RaspberryPI and Volumio is a great option.