I think you'll really enjoy that pairing. I had the Atom HE for over a month, and though I ultimately returned it for refund, using it as a DAC/Preamp, IMHO, most definitely showed it in its best light. Unfortunately I purchased it ONLY to use it in my 2nd system as a true all-in-one, but the internal headphone amp wasn't to my liking. That and the Naim app had faults that I couldn't live with. That said, if I could have used it only as a preamp...it was so good that I would have fought through the app issues, and kept the unit anyway.
My $.02