Suggestions for Connecting Mac to Esoteric K0-3 that requires older OS?

I had been using a MacBook Air connected by USB to a K0-3 for several years. The Mac had an older OS, cannot remember which, that was compatible with the K0-3. That Mac was stolen a week ago, and, after trying unsuccessfully to connect my newer Mac with 10.12.6, I got hold of the friendly Esoteric rep in NJ, who called his connection at Esoteric, to find out that the K0-3 does not support USB with Mac OS newer than 10.9, so as far as I can figure, I'm left with a player that I cannot use for streaming with Mac, since, in turn, Mac does not support their older operating systems; I can't just buy a Mac and install an older OS, and even if I found one used, Tidal requires 10.9 or newer (Spotify will soon not support older than 10.9 either), so I would need exactly a 10.9 OS (until Tidal stops supporting that; what a world). There must be a way to stream from my Mac to K0-3 with newer OS, but darned if I can figure out how. Is there something I could use to bridge between the Mac and the K0-3? (I'm actually running, or did run, the computer to UpTone UltraCap to UpTone regen to KO-3. Good times until computer was lifted.