Hey guys, I've recently purchased myself some HD650s and I am looking to grab myself some RS1s around Christmas. So.. I am after a great amp to drive these two cans. I am looking to get some opinions from people with experience with either of these phones with some amps around the $500 or less price range (new or used). Synergy is something I am trying to figure out. What will go well with both of these headphones? I am currently looking at the Mad Ear+ HD, the WA6 and the Burson HA-160, though I am sure there are others that would suit both of these well. Let me know what you think guys! Edit: A little more information. My DAC is the Audio-GD FUN with Earth OPA. My music tastes lay mainly in indie/rock/ambient/post-rock and a little metal.