The Bricasti M5 would be a first rate option. The M5 is at its best when connecting to a DAC via AES.
+1 for the Bricasti M5 with AES. I've tried my M5 with USB, SPDIF, and AES and prefer the AES. I've decided M5 with AES to my Meitner MA3 bests the integrated Ethernet streamer in the DAC. I also purchased an opticalRendu to compare its USB (used an EtherREGEN for fiber conversion) with the M5 and thought its USB matched it in sound quality. The M5 can be had used now and then for $1600ish which makes it very competitive in my opinion for a high quality Roon endpoint with USB, SPDIF, and AES options...