You can make digital audio sound like anything you want to. There are various plugins for sale for use with digital audio workstations that emulate famous recording consoles, preamps, reel-to-reel tape machines, etc. Some software players have support for these plugins. For example, I think there's a foobar2000 component that can use them as part of the output pipeline.
Distinctly Digital Forever?
Something always made me believe that a decent tube preamp could "mellow" or "naturalize" the sound of digital sources. But this doesn't seem to be so. OTOH, maybe there are DACS out there that not only convert to analog, but actually make digital source components sound like analog sources? So, just to further my understanding: assuming price no object, does there exist any DAC, or DAC/Pre combo, capable of making my streamer (or the best streamer in existence, for that matter) sound indistinguishable from an FM radio signal, given each "playing" the same recording at the same volume with the same EQ?