If the NUC has Toslink optical out that Rock can use (or a USB to Toslink converter) you should be good to go. Otherwise Airplay (If your Phantoms support it, max 16/48 AFAIK) or wait for RAAT. Many use a Raspberry Pi and a HiFiBerry Digi + PRO for this, however. With Ropieee you'd have network RAAT streaming and Toslink to Phantoms.
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Devialetless!
Roon, ROCK/Audiolense XO/Music on NAS/EtherRegen/RoPieee/USPCB/ISORegen/USPCB/Sound Devices USBPre2/Tannoy GOLD 8
250 Pro CI, MicroRendu(1.4), Mutec MC-3+USB
Devialetless!
Roon, ROCK/Audiolense XO/Music on NAS/EtherRegen/RoPieee/USPCB/ISORegen/USPCB/Sound Devices USBPre2/Tannoy GOLD 8
250 Pro CI, MicroRendu(1.4), Mutec MC-3+USB