Tubed DAC w Balanced Out & Volume Control

I'm looking for such a creature for my small bedroom system, to feed a pair of Hypex Ncore 400 monoblocks going into Harbeth P3 monitors. Right now I'm using an (original version) Wyred4Sound DAC2, and am also thinking of checking out a Benchmark - both have balanced outs. But I'd prefer one with a tube output section. Recommendations?

Thanks, Peter