Solid State Power Amp Reviews

I don't know anyone who, having heard the JMF Audio system at AXPONA 2023—the HQS 6002 dual-mono power amplifier ($40,000; footnote 1) and PRS 1.5 dual-mono line stage preamplifier ($36,000) with Harbeth M40.3 XD speakers—did not rave about the sound. In my show report, I credited the system, assembled by Fidelis Distribution and Audio Skies, with delivering "some of the finestsounding music" I heard at the show. "This is the perfect sound for mellow music," I proclaimed. "Bliss."

Naim Audio's enduring, compact 200-series stereo power amplifier has been relaunched as the NAP 250, a key component of their new 200 Series. It has been updated massively in its technology and the compatibility of its connections, yet the primary circuit concept, which dates to the mid-1970s, is essentially unchanged. Recent development work has focused on helping the amplifier match up well with the new NSC 222 streamer-preamp, the NAP 250's intended companion. The new 200-series power amplifier is now called, simply, NAP 250, dropping the "DR" of the previous model. But while the suffix is now omitted, the ultralow-noise DR technology has been retained in the active, fully regulated power supplies; indeed, it has been improved.

When Ayre founder Charley Hansen passed in late 2017, Ariel Brown, who is now Ayre's vice president and chief technology officer, was ready, waiting in the wings. Brown has worked for Ayre since he was a sophomore in college. As John Atkinson wrote in his February 2019 review of Ayre's EX-8 Integrated Hub, "Brown says that for better or worse, he was indoctrinated in Hansen's way of thinking and design. 'I only know the Charley way! Charley never wanted to introduce a product unless we had something new to offer with that product. 'New–Better–Different' was his philosophy; every product had to be a step up from before.'"

And when it comes to solid state amplifiers—the usual kind—does anyone prefer the state of the (germanium) art circa early 1960s to modern silicon class-AB designs? I doubt it.

Now, decades into its own development, class-D amplification seems to have sea legs, even in the audiophile world.

I moved fast. Distributor Wynn Wong would arrive from Toronto in less than a month, to install two Serbian-made Karan Acoustics POWERa monoblocks ($106,000/pair) for review. These monoblocks weigh an astounding 231lb each, with a shipping weight of 286lb; each contains two 2700VA toroidal transformers and a 210,000µF bank of custom capacitors. Each monoblock requires two 15A power cables, one for each amplifier stage.