I dig my Bitfrost, but I'm not sure on the Neuhaus amp... I can crank it up to full volume with the HE-500s and while at a nice loud level, it could certainly go louder. I feel like its not pushing the actuality of the headphones. Sounds pretty damn good to me.. but I bet it can get much better.
I've read around all the threads and it seems to be 50/50 that the Lyr is a great amp choice for the HE-500s.. I know it has more power than my current amp but I wonder if it will increase the quality significantly. I'd spend up to 1k on an amp for these phones