Audacious Audio

Founded in 1984, Boulder Amplifiers is a conservative audio company that goes quietly about its business, choosing not to call attention to itself with marketing flash or acronym-laden features. Change comes slowly to such companies, which is why the just-retired 2010 preamplifier enjoyed a 17-year run.

Several seconds after I began listening to it, I knew that Theta Digital's Prometheus monoblock amplifier ($12,000/pair) was different from other amplifiers. The violins and brass were more dynamic, and had more pace. The orchestra sounded more three-dimensional, depicted in relief by a degree of hall ambience I hadn't heard when I played the same recording through my reference solid-state stereo amplifier, a Mark Levinson No.334.

Powerful, massive, and expensive, Revel's Ultima Rhythm2 subwoofer ($10,000) swept me off my feet when I first saw it in Harman International's suite at the 2013 Consumer Electronics Show. It outsizes, by 49 lbs and 2.6 cubic feet, Revel's previous flagship model, the Ultima Sub30, which I reviewed in the November 2004 issue. Its specs read like no other sub's: 196 lbs; 18" cast-frame woofer; dual 4" voice-coils; 4kW peak power from twin internal amplifiers that generate 1kW RMS; 115dB peak acoustic output; a fully configurable, high-resolution, 10-band parametric equalizer (PEQ); an internal crossover with high- and low-pass outputs; and PC-based setup via USB. The Rhythm2's patent-pending design is said to let just enough air move in and out of the cabinet to prevent any distortion-inducing pressure due to heating of the voice-coils. And its veneer, shape, beveled top edges, and bottom plinth exude the quality found in Revel's top-of-the-line floorstanding speaker, the Ultima Salon2, with which I was familiar.

There may have been a time when vacuum tubes and microprocessors seemed strange bedfellows. But nowadays—given the countless digital processors with tubed output stages, and an even greater number of tubed amps and preamps whose insides are crawling with the latest solid-state devices—we're more or less used to the idea. Here as elsewhere, hybrids are no big deal.

Can an $18,000 power amplifier be a bargain?

Can an $18,000 wristwatch?

Can a power-supply upgrade produce audible sonic benefits? If you've upgraded the power supply of a phono preamplifier, you probably don't need to be convinced that it does, and those usually cost only a small percentage of the price of the model they power. But to add Simaudio's Moon Evolution 820S power supply ($8000) to the Moon Evolution 650D DAC–CD transport ($9000), which I reviewed in the November 2011 issue, almost doubles the latter's cost—though the 820S can be used to simultaneously power two Moon Evolution components, like the 750D DAC ($14,000), 740P preamplifier ($9500), and 610LP ($7500) and 810LP phono preamplifier ($13,000).

For a reviewer, deciding which products to write about is a tricky business. You want to do a professional job of evaluation, but you also want to be able to wrest maximum enjoyment from your music while you do so. Attending audio shows is where reviewers perform sonic triage, weeding out the products that aren't ready for prime time, and making a note of those they wish to invite home after the show.