Constellation Audio Performance Centaur Mono monoblock power amplifier

High-performance audio has always been and will probably remain a cottage industry perpetuated by talented and visionary individuals whose products reflect their singular visions and whose companies often bear their names, though of course there are notable exceptions. One of them is Constellation Audio. No single star dominates the appropriately named Constellation Audio, which arrived on the scene at the 2010 Consumer Electronics Show with a seemingly impossible debut roster of products: stereo and monoblock amplifiers, preamplifiers, digital file player/DACs, and phono preamplifiers, each category of component represented by members of two distinct lines: no compromise and some compromise.

Constellation's instigators-in-chief are David Payes and Murali Murugasu, the Australian duo whose first venture into high-performance audio manufacturing was Continuum Audio Labs, makers of the Caliburn and Constellation turntables, both the work of conceptualizer-in-chief Mark Doehmann and an illustrious team of metallurgists, motion-control experts, bearing specialists, and all the other technicians and craftspeople required to produce state-of-the art turntables.

Though Doehmann is no longer with the company, Continuum soldiers on—as does my Caliburn, having never once malfunctioned in seven years of abuse from yours truly. Payes and Murugasu say they have a new turntable in the works, but in 2008 they decided to add a complete line of electronics to their portfolio, made by a new, independent company. "The idea," Payes told me at CES 2010, "was to develop an electronics company on the same basis as Continuum: find the best designers we could find, and basically motivate and control the design team—and fund it, obviously."

Setting aside the drama of bankrolling an expensive audio startup in the face of world economic collapse, Payes and Murugasu found an anonymous investor who is identified on the Constellation website as "Guru/Investor Ignacio Incognito"—almost as good a handle as "Carlos Danger." When they began searching for a project coordinator, Murugasu, with more than a decade's worth of experience in audio importing and distribution, primarily in the upper echelons, knew what he wanted. They began in Australia, but the search ended in the US with Peter Madnick, who had long been eager to work free of price constraints.

In Madnick, Murugasu and Payes found not only an industry veteran with decades' worth of experience and consumer name recognition, thanks to his association with the modestly priced, highly innovative products from Audio Alchemy, but also one who owned a factory, in Newbury Park, California, with proven capabilities in manufacturing high-performance audio gear. Madnick, who assumed the title of vice president of engineering, assembled a dream team (Google them if you're unfamiliar) that includes, among others, the legendary electronics designer John Curl, the equally legendary James Bongiorno (who has since died) and Bascom King, Demian Martin (Entech, Monster), and the gifted polymath industrial designer Alex Rasmussen, who, aside from being incredibly talented, is one damn handsome man—an annoying combination, if you ask me.

Through the Neal Feay Company, of which he's president—the third generation of his family to hold that title—Rasmussen has done the industrial design for dozens of audio products you've either admiringly ogled or run your hands over—as you inevitably will when you meet, in the flesh, Constellation Audio's exquisite-looking and -feeling Performance Centaur Mono monoblock power amplifier.

Performance Centaur Mono vs Reference Hercules
Constellation's cost-no-object, 275-lb, 1100W (into 8 ohms) Reference Hercules monoblock is priced in Larry Ellison territory at $140,000/pair. The 103-lb Performance Centaur Mono—a single-chassis stereo Centaur is also available—costs a more "affordable" $54,000/pair, though it outputs "only" 500W into 8 ohms, which should be enough to drive most any loudspeaker in a room of any size.

Yet, Peter Madnick assured me, the Centaur's amplifier circuit—and the circuit boards themselves—are identical to those in the Hercules. The biggest difference is that the Hercules uses the highest-quality "through hole" parts, hand-mounted, while the Centaur's boards are stuffed with the best available surface-mount-technology components and soldered by machine.

1113const.ins.jpg

Madnick freely admitted that while the amps' circuits are identical and their sounds similar, the Hercules produces a somewhat more refined sound—as well it should, for almost three times the price and twice the power output. But clearly, the Performance Centaur Mono is the sweet spot of the Constellation line, in terms of quality per dollar which made reviewing it, rather than the Hercules, more useful to this magazine's readers.

Particulars
A design team, led by Bascom King and Peter Madnick, with some front-end input from John Curl and power-supply contributions from James Bongiorno, began by designing a single-ended, 125W, MOSFET-based amplifier that met everyone's specification requirements and produced the requisite sonic glory. That module is the Performance Centaur Mono's basic building block, multiples of which are combined to produce the amp's total claimed output of 500W. The Centaur's sound, Constellation claims, is identical to that of the single module, which begs the question: Why not make and sell that module? After all, 125W is more than enough power for many efficient speakers, and the price could be as attractive as the casework. Maybe it's on the way . . .

The Centaur is a balanced design. So how, you ask, can a single-ended amplifier also be a fully balanced amp? Constellation calls its proprietary topology a Balanced Bridge design.

Instead of the usual push-pull arrangement of N-type output transistors for one half of the waveform and P-type devices for the other half (each of which has somewhat different performance characteristics), within each Centaur Mono are a pair of carefully matched "floating" (ie, not referenced to ground) amplifiers, both using only N-channel MOSFETs. (There are eight transistors on each half-bridge, for a total of 16.) One amplifier is fed the balanced signal's negative phase, the other the positive. The speaker load directly connects the two amplifiers. The unique arrangement is similar but not identical to bridgeable stereo amplifiers that can be configured to produce more than double the power when used as a monoblock. A 1600VA custom-wound toroidal transformer and large storage capacitors ensure that the Centaur never runs out of juice.

The Centaur Mono uniquely includes three input choices: single-ended RCA, balanced XLR, and balanced Direct XLR, the last bypassing the input gain stage and usable only with a Constellation preamplifier. The standard balanced input incorporates a line-stage gain module that uses servo circuits and hand-selected, ultra-low-noise FETs claimed to deliver to the amp stage the same perfectly balanced signal as that delivered by Constellation's own preamplifiers.

The Physical Plant
Despite the Performance Centaur Mono's costing far less than the Reference Hercules, Constellation has spared no expense on its build quality. The sculpted, sloped front panel of pebbly, opaque aluminum, designed and built to the same high standards as the Hercules's faceplate, makes the Centaur among the most subtly striking-looking big amps I've ever seen. It's as unobtrusively handsome as, say, Dan D'Agostino Audio's Momentum monoblock ($55,000/pair; see my February 2013 review) is obtrusively so. Very different but equal "wow factors," to be sure.

In short, you're paying plenty for looks. But these are looks that keep on giving, especially when the Wife Acceptance Factor kicks in—the Centaur's sleek, cool lines might spell the difference between "Not in my house" and "Okay."

COMPANY INFO
Constellation Audio
3533 Old Conejo Road, Suite 107
Newbury Park, CA 91320
(805) 201-2610
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COMMENTS
xsipower's picture

Hello Mr. Atkinson,

I was wondering if you were told what failed on the first unit you were testing at 2 ohms. Was it a fuse? There are four small aluminum panels on the back of the amplifier when removed allow access to ATO (automotive type) fuses.

I'm also surprised the signal to noise measured so poorly. John Curl who designed the input side of the amplifier is known for his superb low noise small signal amplifier designs. See pictures of the inside of the Centaur (can be found by searching the web) they show a rats nets of wires crisscrossing around. Some of these wires come quite close to the transformer.

I understand from the article that this is a "budget" version of the flagship Hercules. It uses the same circuits, but with surface mount components and assembly done in China. Unfortunately the build quality inside the unit does not present itself as a piece of high end audio, especially at the price it's going for. I would say that the metal work of the case is amazing. They must spend a good percentage of the material cost on machining (probably done on a 5 or 6 axis machine).

I think the peaking in the high frequency response is because they do not use an output Zobel network in their design. From the picture of the amplifier module you can see that the output is directly fed from the Mosfets to the output terminals via bus bars that pass under the PCB. The output does not go through a high frequency filter (LRC network). This can make the amplifier susceptible to oscillation with capacitive loads and external ingress of RF signals.

I’m not against five or six figure amplifiers, but I am concerned with:

  1. Poor Signal to Noise for an amplifier of this price and pedigree.
  2. Input impedance way low (way out of specification).
  3. Iffy with loads less that 4 ohms ( specifications say 1000W into 2ohms)
  4. Innards build/wiring quality not up to the price being paid.
  5. Not a big deal, but it concerns me that it has a peaking response in the infra-frequencies.
  6. Probably paying a lot for the glitzy aluminum panels, rather than the meat inside.

Other than that I’m happy that Mr. Fremer enjoyed the units.

xsipower

John Atkinson's picture

xsipower wrote:
I was wondering if you were told what failed on the first unit you were testing at 2 ohms. Was it a fuse?

Yes, as I write in the footnote to the measurements section in this Web reprint, Peter Madnick told me that a fuse had blown.

xsipower wrote:
I'm also surprised the signal to noise measured so poorly....

Me too, which is why I repeated the noisefloor measurement on both samples. But the noisefloor is still low enough not to be a factor in the amplifier's sound quality, I feel.

John Atkinson

Editor, Stereophile

Rick Tomaszewicz's picture

...for being so gimlet-eyed in reviewing ultra high-end gear.  This means we (the 99% - or 99.9%, as another commentor corrected me) can also rely on you for calling out underperforming affordable gear which has a more relaxed price/expectation ratio.

Perhaps your next gig should be evaluating, with the same thoroughness, large government programs prior to their launch!  

Vadim S's picture

Hello Mr. Fremer,

Thank you for the interesting reviews about some of the world's best power amplifiers.

Could you compare the Centaur monoblock performance to the performance of the Soulution 710 stereo power amplifier, at least concerning their basic sonic character? It seems like they share many qualities in common (basing on your reviews of the bespoke components).

Thank you in advance,

Vadim

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