Two years ago, when Boulder Amplifiers first delivered its 3050 monoblocks—the manufacturer’s $205,000-per-pair flagship power amps, which were included in Robb Report’s Best of the Best for 2013—the audio community gasped at their more than 6,000 watts of maximum power, 438-pound weight with granite bases, and ability to drive music like few amps can. The Boulder, Colo., company’s new 2150 class-A monoblock power amplifiers, priced at $98,000 per pair, incorporate much of the technology that went into 3050, b…