Good question...I have not.

I original got echo dots for voice control of the various Crestron controllers I have networked throughout my system and also took advantage of the analog outputs on the dots to provide an additional audio source in each room. Of course the sound from the dot is nothing to write home about. The echo link provided a way to use an outboard DAC in my main listening room for streaming audio and that is why I purchased it. The entire purpose was to avoid using Amazons built in DACs. Since it cost more and is intended for integration into better sound systems, you would think/hope Amazon included a better DAC in the Echo Link than they did in the Echo Dot.