Is there a music server component that can stream internet music sources to your DAC without needing a laptop, tablet or smartphone device?
None that I am aware of. You need some way to connect the device to what you want to hear. The closest might be a Sonos, using its digital output, but even then you still need some way to communicate with the Sonos and tell it what you want it to do, and they rely upon an iPhone or a tablet or computer to talk to the Sonos.
OK, so here is a new product idea for you. I am no tech expert, just an audio lover. So here is a “customer perspective” on what I would like.
A system component that will connect to (wifi etc.) and allow you to browse the internet for audio streaming sites. So it would have a wireless keyboard and a display or allow you to use other displays like your tablet if you don’t want to buy its display. It would be cheaper than a dedicated laptop because it would not have the computing power or software of a laptop. It would be better than a laptop as a source because it would have optimized output for audio (better USB like integrated LANRover and other output options) and easily integrate with better external DACs. It would not provide CD playback or music storage but easily integrate with CD transports, network attached servers and music servers.
Is there a need for this or am I missing something that already exists?
P.S. The whole idea here is that a laptop is not the best source component in an audio system because it way over performs in terms of computing capability but under performs in terms of music reproduction and integration with an audio system.