I've had the opportunity to audition the 850 monos. I've heard them with JM Focal Utopia Be's and both Accuphase and ML 390 digital sources run through a Boulder 1010 (could have been the 1012). These amps have a small footprint but a big voice, though I wasn't in love with high frequency reproduction. Yes, they are fast like their big brothers but rather than drop $10K on these I'd spend a bunch more for the 1060 stereo amp to get the finesse and grainless top end. They're not an inexpensive entry level component but for those with a limited budget they do get you a taste of the Boulder flavor.
