If you've bought into Amazon's ecosystem of smart home features and you have a high-end audio system, then the Echo Link is intended to bring those worlds together. Announced earlier this year alongside devices like the Echo Sub and Fire TV Recast, it doesn't contain a microphone or speaker like the Echo Dot. Instead it simply delivers quality audio to your existing amplifier and/or speakers at the command of Alexa-connected apps and devices.
Better yet, it doesn't only work with Amazon Music -- Spotify, Pandora and Tidal work out of the box with Apple Music listed as "coming soon." As far as the hardware, it's a simple box made to fit in on your shelf of equipment, with just a volume dial and headphone jack on the front, plus various ins and outs on the back.
If you need to have an amplifier integrated into the box, you'll want to wait for the appropriately-named Echo Link Amp that's coming out next year. It adds a 60W two-channel amplifier to the mix and another $100 to the price. Right now, however, the Echo Link is your only option at $199.99.