I Have a Boulder 2060 Audio Research Ref3 combo. I have had Avalon Osiris, Dynaudio Temptations and now MBL 101e's. I'll make it short and sweet. They were outstanding with each speaker. The reasons for the changes had to do with the speakers, since this amp/pre combo simply reveals what's farther down the chain. All of the speakers need power to extract their best performance. Power that allows for the speaker dynamics to come through. The Boulder has it all: soundstaging, imaging, a "you-are-there" sense of dynamics and a terrifc musicality. I can listen for hours to vastly different types of music and be happy. I went through Rowland 9Ti's, Pass 600's and Krell 750 Mcx's. The Krells were the only ones that came even somewhat close. I do wonder what the new Krell Evolution series would sound like, but I'm really done for now(yeah, sure).
Daviud Shapiro