Omnidirectional speakers are nothing new, though there are many variations. For example, Italian maker Bolzano Villetri has taken an interesting approach with its Campanile series, which includes floorstanders, a center-channel speaker, and a subwoofer to outfit a complete home theater.

It seems I spoke too soon. Last week, I profiled the Audio Note Gaku-On monoblock, calling it the most expensive power amp I know of on a per-watt basis, which was a true statement at the time. But as soon as I posted that profile, Cornelia Davis of Audio Federation informed me of another tube-based monoblock that, watt for watt, costs even more—the ML3 Signature from Brooklyn-based Lamm Industries.

When you consider the price of a power amp, it's interesting to calculate the cost per watt. In that light, the Gaku-On monoblock from British maker Audio Note and distributed in the US by Audio Federation is the most expensive power amp I know of.

Is the NL Reference from Florida-based Edge Electronics just another high-power, high-priced monoblock power amp? I think not.

There are power amps, and there are power amps—and then there's the Pivetta Opera One. Standing six feet tall and weighing over half a ton, this monster is designed by Pivetta Andrea (pictured here with his creation), built by the Italian company bearing his given name, and distributed worldwide exclusively by HigherFi.

I don't typically cover so-called multimedia speakers in this blog, but when I came across an ad for the GLA-55 from Harman Kardon in an upscale magazine, I was intrigued. The cabinet looks like it was chiseled from rock crystal, and its beauty turns out to extend well below the surface.