Anyone directly compare the ASL MGH and the Berning ZOTL? With or withour NOS. (haven't seen this in the archives). I'm looking for a good tubed amp. Any one heard the ASL Reference Tool? To use with 600's (or even SR-1's) Thanks Tom

I've decided to plunge into a home based hi-rez headphone system. I currently have 4P's running directly from a portable source for travel. I'm thinking of the Sen. 600's matched with a quality amp in the $1-2,000 range and that's where I need help. In my stereo system I'm partial to tubes. I...