I spend a lot of time cheerleading for integrated amplifiers. I like their spacesaving footprint. I like eliminating the interconnect and with it the ancillary circuitry required for preamp and amp to shake hands electrically. In recent months I’ve partied with some of the best— MBL, Plinius, Chapter, and conradjohnson, all splendid ambassadors of the breed. Indeed, I was feeling pretty smug. And then the MBL 121 Compact Radialstrahler loudspeaker took up residence in my listening room. Its lust for power was unnerving; at 82dB sensitivity it was even more voracious than my own 83dBsensitive ATCs. Clearly it was a remarkable speaker, but I felt that I wasn’t taking its full measure. The last thing I needed to do was to inadvertently put it on a wattage diet. This glutton needed a bigger trough. It needed the power and reserves only a dedicated power amplifier can provide.
Enter the Plinius SB-301, a good old Class AB solid-state stereo power amplifier bristling with 310Wpc. Because of its heavy Class A bias, it’s been wisely outfitted with enough heatsinking to cool a reactor—so don’t count on it to earn any Energy Star compliance medals. The beefy grab handles testify to its eightyplus pounds—enough to blow the zipper on Jack LaLanne’s jumpsuit. However, for those expecting the re-styled curvilinear treatment of Plinius’ new integrated amps and its multichannel Odeon, forget it. The old-school look of the brawny Kiwi reflects electrical DNA that stretches back to the Class A SA-102. In fact, the SB-301 essentially mimics the 102’s circuit topology and raises the ante with a more robust output stage with double the output devices, a larger power supply, and larger twin toroidal transformers.
I’ll cut to the chase. The SB-301 is the best amplifier I’ve reviewed to date. Hugely powerful yet lithe and graceful, it’s like Godzilla in Capezios. It launches dynamics that you thought your speakers weren’t capable of. Time and again, it put some of the world’s most demanding models through their paces—like the aforementioned MBL 121, my own ATC SCM20-2, and, in a brief listening session, the Wilson Duette. In the case of the Wilson (which Paul Seydor reviewed in Issue 176), I listened to Leonard Bernstein conducting Carmen [DG], and the Wilsons seemed to enlarge and bloom like the time-elapsed images of a vase of roses. The Duettes, already formidable in the dynamics department, sent forth a rush of uncompressed energy the likes of which I’ve never heard in a compact speaker. In every instance, the Plinius managed to fill the Duettes with more energy and drive and to bring out dynamic shadings and pitch references that other amps struggled to retrieve.
For the record, the SB-301 is neutrally balanced, conveying just a hint of ripeness in the midrange and an element of warmth in the lower mids and upper bass. I prefer the darker, richer energy in the mids for the way it makes voices sound as if they are originating from the diaphragm, rather than the throat. Also purged in this design is the whitish rise in the treble that I noted in earlier Plinius models. The result is a treble that is nearly romantic, yet not so roundly euphonic that one would be reminded of a retrobrand of tube sound. Its performance will be as luminous and unconstricted as your tweeter and cabling allow; if you don’t hear a cushion of air beneath harmonics, something is awry. Low-end resolution and control are models of solid-state excellence—a breathtaking example being the chocolaty bottom octave of Peter Wispelwey’s cello during Kol Nidre [Channel Classics].
But it’s when the Plinius turns its attention to the subtleties of sound reproduction that it truly shows its greatness. To begin with, backgrounds are eerily quiet and raven-black. This allows the Plinius a palette of tonal colors that is as vivid as anything I’ve heard. It simply heightens performance and timbral details like few others, making any instrument at any volume instantly identifiable. Imaging is articulate and uncluttered (no surprise since the Plinius’ larger power supply/ dual transformer combo means superior channel separation). Like past Plinius amps the SB-301 also has the timing down. On the macro-level it drives the music forward, locks onto rhythm sections, and propels hip-hop pulses. On a microlevel it has the ability to align, focus, and sustain the fundamentals and harmonics of a solo grand piano [The Lark, Kissin, RCA]. The SB-301 articulates dynamic gradations and transient information with astounding delicacy. Whether I was listening to an a cappella line of Laurel Massé [Feather and Bone] or the firecracker mandolin virtuosity of Chris Thile of Nickel Creek [This Side, Sugar Hill] or Edgar Meyer digging deep into his acoustic bass [Appalachian Journey, Sony], I became keenly aware of the “touch” of the performer always modulating volume and attack. Weaknesses? Soundstage depth and layering might be improved, but not by much. As for its competition, my listening room door is always open.
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