March 2003

Plinius SA-102 Stereo Amplifier

by John Leosco

Enter Brutus

From across the room, the $4995 USD Plinius SA-102 assumes the stance of a bulldog: stocky and appearing more wide than deep. In fact, the 83-pound metallic lump measures 19 3/4"W x 18"D x 8 3/4"H. Massive fern-like heatsinks jut past the thick, attractive faceplate on both sides, and two large milled-aluminum handles adorn the front. The bright silver finish (the amp is also available in black) glistens like solid aluminum billet. Visually, the SA-102 screams manly bravado and should sufficiently impress your audiophile buddies.

Positive first impressions don’t stop with a cursory glance, either. Two pairs of grab handles, front and rear, help with maneuvering the weighty amplifier toward a desired spot. Sturdy all-metal binding posts with hexagonal nuts are easily tightened with a 1/2" box wrench, and you can tighten away until your speaker-cable spades wither. Four posts per channel allow for biwiring. An IEC mains socket and detachable cord provide the juice, and a handy ground-lift switch disconnects signal ground from the chassis. With the SA-102, no cheater plugs are required to eliminate ground-loop hum.

Balanced and single-ended inputs, with specified input impedance of 47k ohms per phase, flank the Amplifier Configuration Selector. This four-position switch selects operation in RCA Stereo, RCA Bridged Mono, XLR Stereo, and XLR Balanced Mono modes. Used as a stereo amplifier, the SA102's rated output is 125Wpc into 8 ohms, and as a bridged or balanced mono amplifier, the output power increases by about four times to 460 watts into an 8-ohm load. More significantly, the solid-state SA-102 is a powerful design capable of short-term current delivery approaching 30 amps per channel. The heavy-duty power supply is separated into two distinct circuits; the first supports the driver stage and the other feeds the bipolar output stage. Siltech silver cable is used internally for input and output wiring.

Once the amp is connected and configured, depressing the main power switch on the front panel starts a ten-second initialization sequence. When the central blue LED stops blinking and glows continuously, the SA-102 is ready to play. A small switch left of center will mute the amplifier by internally disconnecting both the inputs and outputs, ideal for facilitating cable changes. If the LED near the switch is on, the amp is muted.

The right switch alters the operating bias of the amp, with class AB as the default. Flipping the metal switch will light the bias LED indicator and select class A, recommended for more critical listening. The Plinius amplifier will quickly become very hot in class A, placing those big heatsinks into action dissipating energy. After a three-hour warm-up, I measured the maximum temperature near the chassis/heatsink joint at a blazing 165 degrees! In comparison, my Ayre V-1x and Krell KSA-150 run about 135 and 145 degrees respectively. However, the SA-102 is designed to run this way continuously, and the heat that is felt is reportedly kept away from the internal parts. An internal microprocessor automatically switches the amplifier back into class AB if no signal is present at the inputs for a predetermined time; or you can simply flip the bias switch again. The bias reset time can be adjusted to 15, 30, or 60 minutes or off completely by moving a jumper on the main circuit board.

Plinius considers class-A operation to be lower in distortion than other operating classes. Constant current flow independent of demand stabilizes the rail voltages by reducing power-supply modulation. Let’s just say the amp should sound better in class A; thus, I listened to the SA-102 as a stereo amplifier and primarily using class-A bias.

Considering its abundance of options, the Plinius SA-102 sets the standard as an ultra flexible, large-scale amplifier. There are no physical concessions anywhere to gripe about. Even the brightness of the three frontal LEDs can be tailored to satisfy your personal tastes. The comprehensive instruction manual, available online, gives complete setup instructions.

Supporting cast

My review system consisted of a PS Audio Lambda CD transport feeding bits to a Dodson Audio DA-217 Mk II D digital processor via an Illuminations D-60 digital interconnect. An Ayre K-1x preamplifier routed analog signals through single-ended AudioQuest Diamond and balanced Synergistic Research Resolution Reference Mk II and Acoustic Zen Silver Reference II interconnects. The B&W Nautilus 801 performed as my loudspeaker of choice with Synergistic Research Designer’s Reference and Resolution Reference, and JPS Labs Superconductor+ Petite speaker cables. An API Power Wedge 116 conditioned AC power to the front-end components.

"Friends, Romans, countrymen, lend me your ears"

It wouldn’t matter how impressively conceived and built an amplifier is if it didn't sound good. I’m delighted to report the Plinius SA-102 surpasses good sound to deliver a wide range of music in convincing fashion. For example, the powerful classical works of Gustav Mahler were reproduced with grandeur and grace. Distinct players emerged from a voluminous hall and built together toward intense orchestral climaxes. All of Nirvana’s raw energy and fiery angst were clearly communicated to an audience of one. Marvelous vocals from Barbra Streisand played as both seductive and potent. Everything I threw at my system came back to me well rendered by means of an even-handed approach.

Then the Plinius SA-102 completely blew me away with its explosive dynamic impact. Violent drum strikes, in particular, tried to shatter my eardrums. With Marian McPartland’s Hickory House Trio -- Reprise [Concord Jazz CCD-4853-2] in the tray and the volume set to a realistic level, some vigorous cracks of Joe Morello’s sticks caused piercing pain to my ears -- followed by a toothy, ear-to-ear grin. I’ve never heard a drum set re-created so faithfully. Each and every impulse was super sharp and quite focused with natural decay, like the real thing. An amplifier capable of energy bursts of this magnitude should blast life from almost any loudspeaker.

Despite its awesome dynamic potential, the overall character of the Plinius amplifier is not aggressive or forward. Its signature always leans toward neutrality and moderation. Morello’s cymbals ring true and shimmer across the stage with sparkle and air, but the highs could never be described as too hot. Bass response is very deep and controlled, but also rich. Certainly, pairing the SA-102 to loudspeakers capable of total extension will allow the amplifier to strut its stuff.

In my experience, more than a few solid-state amplifiers fail in the midrange. Some are so clean and clear (often mistaken for superior accuracy) that music through them appears precise, but also hyper-detailed and threadbare. Others go off the deep end emulating old-school tube amplifiers and their correspondingly lush results. Once again, the Plinius SA-102 takes the middle ground by sounding detailed with sufficient warmth.

From Tracy Chapman’s self-titled debut album [Elektra E2 60774], "Behind the Wall" is a haunting solo work that chronicles a neighbor’s exposure to domestic abuse. Chapman’s solitary voice, chased by only a hint of room echo, acts to heighten the feelings of despair and pain. Image focus seems appropriate, neither wildly blooming nor pinpoint, but a stable centered shell of emotion located at the speaker fronts.

Directly in contrast to the stark isolation of "Behind the Wall," each successive worldly track of bluesy folk-rock plays like a veritable rhapsody. Rhythmic full-range music showcases the strength and overall balance of the Plinius SA-102. Authoritative bass forms a strong, pulsing foundation. Clean percussion taps both set the tempo and accentuate the melody. Guitar strings snap to attention and ring down harmonically beside Chapman’s full vocals. Nicely done, all.

I’m speculating here, but the musical and midstream nature of Plinius’ SA-102 along with the absence of fatal flaws should allow it to perform well with a wide range of components. It certainly did the job in my system.

"Et tu, Brute?"

When compared to my reference Ayre V-1x amplifier, the Plinius SA-102 disclosed one or two small chinks in its heavy armor, and only then reluctantly.

Listen to Joni Mitchell’s angelic pipes on the remastered Blue [Reprise 2038-2]. Through the Ayre amp, Mitchell's soaring vocals project outward as a focused central core surrounded by a halo of displaced air. The Plinius amp is obviously not as forward. The SA-102 also makes a lesser distinction between the point source and its surroundings, in turn displaying a more homogeneous yet effective image. Lateral image size remains about the same from amp to amp. Individual notes sound a little crisper through the Plinius, slightly richer with the Ayre. I don’t consider this a big issue of right vs. wrong, but closer to a slight difference of opinion on which I could argue for either side.

Using well-recorded piano, the battle lines become more clearly drawn. Mitchell’s accompaniment on "My Old Man" cascades across the soundstage from keystrokes originating just inside the left channel. On this track, my B&W Nautilus 801s form an imaginary enclosure like two invisible baffles protruding into the room. Through the Ayre V-1x, vivid chords try to break free from the enclosure as if they are too sonorous to be constrained. There is more air with the Ayre. Comparatively, the Plinius SA-102 creates a somewhat detached feel, with the notes comfortably contained between and behind the speaker faces.

The two solo piano cuts from Mark Levinson Live Recordings at Red Rose Music, Volume 1 [Red Rose RRM 01] confirm it. With the Ayre V-1x in my system, the piano appears three-dimensional, almost like a real instrument being played within my room. The Plinius SA-102 offers a more removed spectator’s perspective, which some might prefer.

Before jumping to any conclusions, keep in mind the synergy factor. My Nautilus 801s are so intensely dynamic that they don’t need additional boost from an amp like the Plinius SA-102, just as they fully appreciate the Ayre’s added warmth. Recently, while completing this evaluation, I received a review pair of Dynaudio Confidence C4 loudspeakers. If first impressions prove accurate over the long haul, the Dynaudios relish the punch of the Plinius. Stay seated for Act II.

I’ve waited until now to discuss the difference in price. One Plinius SA-102 amplifier retails for a little over half what the Ayre V-1x sells for. You could buy two Plinius SA-102 amplifiers for ten grand, run them in mono, and possess enough potential energy to level entire city blocks (well, almost). Or you could be very satisfied as the proud owner of a single stereo Plinius SA-102 and be $5k richer.

The verdict

There are a number of ways to consider the Plinius SA-102. First, look at its solid build quality and admirable fit’n’finish. Then consider its powerful and pleasant middle-of-the-road musical view. The SA-102 delivers thunderous, realistic dynamic impact and only gives away a touch of perceived presence to pricier amps like the Ayre V-1x. It’s a very enjoyable amplifier to listen to, with all kinds of music.

Finally, check your wallet and ponder the SA-102's price tag. Only in the wacky world of high-end audio would someone with a Roman statesman's budget consider the $5000 price point to be mainstream. But can a $5000 amp be a bargain? If so, the Plinius SA-102 is at the top of the list.

...John Leosco
johnl@soundstage.com

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