Im looking into buying one of these amps. If i get the Woo Audio WA6SE, i would be connecting it to my NuForce uDAC2. I've seen many threads about the WA6SE, and some about the HA-160D, but I havent seen a comparison between the two. Has anybody had the opportunity to compare these two amps? I plan to use grado SR325 or Sennheiser HD650.