Accuphase M-2000 monoblock power amplifier

Just after I agreed to review the Accuphase M-2000 monoblocks, importer Arturo Manzano began urging me to take the Accuphase PS-1200 Clean Power Supply as well.

"Arturo, who's gonna pay $27k for a pair of monoblocks, then another $8200 for a power conditioner?"

He looked at me as if I was making a bad joke. I often do.

"That's a trick question, right, J-10? Uh...all of them?"

That gave me something to think about. If occasionally you wonder just who in the world is buying this ultra-ultra stuff, consider that there must be enough of them to keep these manufacturers turning it out! That, and the manufacturers' desire (which most seem to harbor) to build cost-no-object statement products that embody their best efforts. Then there's the trickle-down factor: In the High End, improvements at the $27k level very quickly flow down the line into $2700 gear.

So let's turn our beady-eyed attentions to the device in question: the Accuphase M-2000 monoblock.

$27,000 build considerations
"Yeah, and for that price," I hear you hummin', "it better be made outa gold." Actually, the M-2000 is built to a very high specification. When the Japanese are into something, they're into it.

The M-2000 monoblocks punch out a claimed 2000W into 1 ohm, 1000W into 2 ohms, 500W into 4 ohms, or 250W into 8 ohms. If you're power-hungry—and, let's face it, these are power-hungry times—the M-2000 can be run bridged for four times the power delivery. A bridged pair per side yield 4000W into 2 ohms, 2000W into 4 ohms, and 1000W into 8 ohms. However, being a person of modest demeanor, I made do with but a single pair.

The M-2000 is strictly a class-AB amp: no wasted energy. It did, however, become fairly toasty after a hard evening's listening session, and idled warm to the touch. The amplifier is powered by a huge 1.6kVA toroidal power transformer. Accuphase reminds us that toroids offer low impedance, efficient operation, and "compact size." I don't know what they're talkin' about: The M-2000's Super Ring transformer is HUGE! It features a near-circular core and circular windings, offering "a high packing density resulting in low flux leakage and reduced vibration." In addition, Accuphase explains, the smaller diameter of the ferrite core and the copper windings with "high specific gravity" make for low magnetic losses and low inrush currents.

The incoming balanced signal is connected directly to inverting and noninverting input stages for true differential operation. The "modular construction" output stage features newly developed high-power transistors that Accuphase says have excellent high-frequency response, current amplification linearity, and switching characteristics. Couldn't find out much from the documentation about what lay between the input and output stages, but there I found 22 output devices run in parallel push-pull configuration mounted directly to big aluminum heatsinks.

The M-2000's feedback loop uses signal current rather than voltage. Accuphase describes it thus: "At the sensing point of the feedback loop, the impedance is kept low and current detection is performed. An impedance-converting amplifier then converts the current into a voltage to be used as the feedback signal. Since the impedance at the current feedback point is very low, there is almost no phase shift. 'Heavy feedback,' with all its associated disadvantages, is no longer required. Phase compensation can be kept to a minimum, resulting in excellent transient response and superb sonic transparency." You know they were staying up late sweating the details.

Last but not least, every millimeter of the signal path is gold-plated. That includes the copper traces on the circuit boards, the bus bars on the ground plane, and the power transistors, input jacks, and speaker terminals. See? It is made outa gold.

Each M-2000 is about the size and density of a YBA Passion monoblock—Sumo wrestler substantial, but not outrageously huge or heavy. The chassis and heatsinks are clad in attractive, dark-brown Nextel, and thus ringeth not. There's a nice tactile quality about them, the subtly textured finish adding a touch of class to the thick, burnished, golden-hued faceplate and handles. Reinforcing the Lush Life image, the action of the Meter On and front-mounted Power On buttons is nicely weighted.

The M-2000's rear apron is bracketed by a second set of grab-bars for easy schleppage. Each amp weighs 110 lbs, so I found the bars a civilized and welcome touch. Between them are a huge pair of...knobs. (Where's Bill Maher when you need him?)

These huge, robust, custom-made speaker terminals were easy to use; they're made of extruded, high-purity brass, and gold-plated (isn't everything?). The large, easy-to-grip molded plastic caps made a breeze of tightening down even the most willful and ornery of cables. (Really, some of them are like mythical serpents!) The capacious "insertion passage" (ahem) between the supporting posts and the screw-down cap lets even the largest spade-lugs settle in comfortably.

The rest of the rear panel reflects the engineering aesthetic so endemic to Japanese culture, as Desmond Morris might point out. There are single-ended (RCA) and balanced (XLR) input connectors, with an associated input selector and polarity switch. In its uninverted state, the M-2000 adheres to the rather arcane standard of pin 3 hot, pin 2 neutral; unless you're running a full Accuphase system, you'll want to run it inverted. When I ran the amps uninverted, ie, 180° out of absolute phase, the sound darkened a bit, extension at both ends suffered, and imaging was less precise. An L/R Channel Selector switch can be left in either position for the present; a digital input module is planned for the future. Lastly, there's a standard IEC AC fitting with a 20A circuit breaker in the line.

Up front, the M-2000 is "very luxious," as K-10 described it. The substantial, beautifully finished faceplate is set off by a large peak-reading power meter "under glass." The look is classy and upscale. I did most of my critical listening with the meters off, but did check them initially while getting to know the amps—what I saw wasn't always what I got. To some extent, the meter reading must be interpreted in terms of the speaker load. The meter is calibrated in decibels and watts referenced to a 2 ohm load: –60dB to 3dB. If your speaker presents a 4 ohm load, halve the reading; with an 8 ohm load, quarter it. Einstein was right: everything's relative. After a while, I just turned 'em off.

Peering into the M-2000's décolletage through its mesh top, I was struck by the size of the central-mounted Super Ring power transformer, surrounded by sleek, black, soda-can–sized capacitors.

When I backed up to consider their general form, the plush-looking M-2000s exuded a confident, refined, handsome aspect—in the Japanese idiom, one might say.

Neither a headbanger nor a wussy be
Accuphase specs the M-2000 at a continuous average power of 1000W into 2 ohms! Into the JMlab Utopias (3.3–6 ohms), the amps must yield something on the order of 325–350Wpc-plus headroom. And, relatively speaking, that's how they sounded.

Listening to Kruder and Dorfmeister's The K&D Sessions (!K7 K7073), I normally get off on the deep, powerful bass crunches that take off and pound down the alley. For best effect, an amplifier has to pump out a solid foundation, on which the enveloping soundstage and vocals can be built. Listening carefully, I tracked through this great two-CD set at room-pulsing levels, the M-2000s putting their broadest shoulders to the task. The result was power and control in the bass near in quality to the Forsell Statement, itself good for about 350W into a load of 4–6 ohms. The bass was good, nicely pitch-differentiated, quite deep-going, fairly well-controlled, and just transparent enough to get away with its slight plumminess. The Linn Klimax monoblock, specified at 500Wpc into 4 ohms, gets the power transfer just right and sounds altogether more tight, snappy, and tuneful.

When I listened to the involved, meandering acoustic bass intro on "Use Me," from Patricia Barber's Companion (Premonition/Blue Note 5 22963 2), the Accuphase proved somewhat less "grippy" and authoritative, a bit softer, with less overall impact and dynamics, than the Linn. Not ponderous by any means—it could sound huge and encompassing—but less lithe, quick, and pitch-differentiated than the wee Scots tykes. Understand, the M-2000 was anything but wimpy. But in HyperExpensive SuperAmp Land, I like it the Linn way: tight, tuneful, and fast, bay-bee.

Company Info
Accuphase
US distributor: Axiss Marketing
17800 S. Main St., Suite 109
Gardena, CA 90248
(310) 329-0187
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