Hello all, I am new to this forum and high efficency speakers. My current rig which I intend to keep, consists of all modded or highly modded gear to include a Musical Concepts Hafler DH 500 amp, Dynaco PAS 3x pre, Magnepan 12 qr "gunned" speakers, a 90 lb. Lenco L75 table, and a Prima Luna 8 cd player. The Magnepans are like a old whore at the dock's when it comes to power- You can't give 'em enough! So a few weeks ago I heard a friend of a friends rig that was very different than my own though it sounded very special. His gear consisted mainly of Bottlehead amplification in front of home built cabinets (6.5 cu. ft.) housing Great Plains Audio 604-8h11 drivers. When he fired it up I was stunned how organic and right this "old timey" system sounded. It was nothing like the Klipsch Lascala's that I heard in the military so many years ago (Jam a screw driver in your ear). During our informal session I made a few observations; The 604's did a few things better than my modded maggies such as a much wider sweet spot, (you could walk around the room without penalty) better low level resolution, and slightly bigger dynamics. Having said that, the Magnepans were more holographic with a deeper sound stage, and to my ears, better and smoother treble. I understand that associated gear, room, power conditioning etc.. made these comparisons pretty subjective and un-scientific to say the least. So here I am having decided that I can not live without BOTH the Magnepans and the Great Plains 604's. I have however have decided to get the 604-8h 111's instead of the 11's and I will be using a 10 cu. ft. box (thanks to Jay Fisher). The 500 wpc Hafler is probably not ideal for driving that GPA's so I am looking for suggestions. Understand that I know nothing about output tubes, push pull vs. single ended vs chip amp, or how to bias. I do want to stay away from "flea powered" amps like 45's etc.. as I am prone to crank Rush and Sammy Hagar to big room filling levels. I have a budget of $1500.00 US dollars for a used piece of gear. Happy Holidays.