Amazon devices with Alexa do not have digital output, but my work-around using Amazon Music Unlimited with Alexa is to use a mic connected to my PC (with WO Mic client) and I then have up to 24bit/192MHz sound on my stereo amp set-up. [My PC has a dedicated hi-spec soundcard.] I've not actually done an A-B test of AMU via the PC card only versus AMU via the Alexa app, but both do generally sound superior to AMU via the line out option from Amazon Echo Dot 3rd Generation - the last Echo Dot model to feature line out.