AOM Logo March 1998

Celestial Heights
SimAudio's Celeste Moon W-5 Power Amplifier

Andrew Chasin

For a country whose entire population amounts to less than that of New York State, Canada produces more than its fair share of quality high-end audio gear. Companies such as Classé, Oracle, Sonic Frontiers, Totem, and Waveform have established themselves firmly as leaders in an industry heretofore dominated by American brands. While not yet having attained the same level of international recognition as the exalted members of this short list, Québec’s SimAudio, manufacturers of the Celeste line of electronics, is certainly poised to do just that with its upscale Moon series.

SimAudio was founded in 1980 as Sima Electronics by then chief designer Victor Sima. The company produced an affordable line of high-quality amplifiers and preamplifiers which sold well in Canada, Europe, and Asia, but was a permanent member of the endangered species list in the critical American market. In 1992, the company, now known as SimAudio, set its sights firmly on the more upscale segment of the audio electronics market with the introduction of the more ambitious Celeste line of amplifiers and preamplifiers. The first Celeste-branded product to reach the market was the highly-regarded W-4070 power amplifier, which featured the first commercial realization of Sima’s zero-feedback "Renaissance" technology. In 1993 Sima left the company to pursue other interests, leaving partner John Poulin at the helm. Poulin’s long-standing desire to build a no-holds-barred power amplifier, which could compete with the Krells, Levinsons, and Rowlands of the world, led to the introduction of the Moon W-5 amplifier in 1996. The W-5 has since been joined by other products in the Moon series including a two-box preamplifier, a remote-controlled integrated amplifier, and, more recently, the 100 Watt/channel W-3 power amplifier. A top-loading, one-box CD player is also said to be in the works.

Celeste Moon W-5 Power Amplifier

Fine Points
The solid-state Moon W-5 is SimAudio’s most ambitious amplifier to date, and is a visual and sonic tour de force. As in the W-4070 which preceded it, gone is the ubiquitous rectangular black box, replaced instead by an oval chassis, capped, in this case, with a stunning, bluish-purple, brushed aluminum faceplate. A single, central, blue LED is the only visual evidence of the W-5’s electrical readiness. Integrated metal handles run the depth of the chassis, and aid in movement of the W-5’s substantial 72 lb. weight. Four gold, height-adjustable steel cone footers complete the W-5’s unique visual appearance.

The rear of the unit sports a rocker-style power switch, a detachable power cord, a single pair of high-quality, gold-plated WBT loudspeaker binding posts, two pairs of single-ended and one pair of balanced inputs (one single ended input is phase inverted), and a small fuse holder. An inconspicuously small reset button is located adjacent to the fuse holder. Curiously, the user’s manual supplied with the W-5 makes no mention of the reset button - a glaring omission since the amplifier will refuse to power-up after its initial connection to an AC source (or after a power failure) until this button is depressed.

The Moon W-5 is most certainly a mature design, one conceived by science and refined by ear

Although a relatively new product, the Moon W-5 is most certainly a mature design, one conceived by science and refined by ear. The W-5 is a dual-mono design incorporating SimAudio’s zero-feedback Renaissance circuit. While many designers rely on at least some degree of global feedback in order to maintain acceptable levels of distortion and ensure amplifier stability, John Poulin (and others before him) believes firmly that global feedback is to be avoided if an amplifier is to exhibit realistic transient response. Although the Renaissance circuit contains no global feedback, it is said to be extremely stable and low in distortion. While I haven’t been made privy to the details of the Renaissance circuit, and therefore can’t describe its theoretical basis, I can attest to its infinitesimally short reaction time, and its ability to track with ease, the most abrupt changes in a musical signal, without any signs of distortion or amplifier instability.

SimAudio has spared no expense on the W-5’s internal components. Custom made power transformers, mil-spec circuit boards, high-quality parts from Dale, Motorola, Vishay, and Wima, and slow-rolled, OFC internal wiring are just some of what constitutes a Moon amplifier.

As supplied, the Moon W-5 produces 175 Watts/channel into 8 Ohms, its power output doubling into successively smaller loads. Although few will need more power than a single W-5 can deliver, it is possible to bridge two W-5s for mono operation, resulting in a combined output of 700 Watts/channel - more than enough power to bring even the most stubborn full-range ribbon or electrostatic transducer to life.

According to SimAudio, the Moon W-5 will not reach its full sonic potential until it has been powered without interruption for at least three days. My own aural observations bore this out, and the review sample was left powered-on continuously throughout the evaluation period. Doing so never left the W-5’s curved heatsinks more than mildly warm to the touch. The W-5 also requires an extended break-in - expect to be underwhelmed for the first 50-75 hours. During that time, expect a sound which is overly analytical, and lacking in natural warmth and body. Rest assured that these undesirable characteristics will soon fade away, leaving behind a sound which is both tonally rich and naturally detailed.

The Sound
The once-clear line separating solid-state from tube sound is getting decidedly blurry. It is not uncommon these days to find tube amplifiers which have, for example, a level of control and definition at the bottom-end of the spectrum once the exclusive domain of solid-state devices. Similarly, several of today’s solid-state amplifiers can sound as tonally natural and grain-free as the best tube devices. Such is the case with the Celeste Moon W-5 power amplifier. Not only is the W-5 a significant overachiever in the usual areas in which solid-state devices excel, but its smooth, liquid presentation will almost certainly bring smiles to the faces of those who prefer the sound of tubes but the convenience of transistors. With the W-5, you can finally have your sonic cake and eat it too.

The Moon W-5 is so coherent tonally that it’s almost an injustice to focus on its reproduction of a specific area of the sonic continuum. I would be remiss, however, if I didn’t bring its stunning bass reproduction to the fore. Simply put, the W-5’s depth, definition, control, and articulation of music’s lowest octaves was nonpareil in my experience. Listen to Enya’s Watermark (WEA Z4 38751) or Respighi’s Pines of Rome (Chesky RC 5) with the W-5 in the reproduction chain and prepare yourself for a low-frequency joyride. Bass drums explode with tremendous power, yet never overstay their welcome. Kick drum is tight and punchy, rising sharply and decaying naturally. Double bass growls with intensity, providing the most solid of orchestral foundations. Even in the context of the most demanding of low-frequency passages, such as those heard on Holst’s Suites for Military Band (Reference Recordings RR 39), the W-5 proved unflappable.

Another hallmark of the W-5's performance was transient speed and control

Another hallmark of the W-5’s performance was transient speed and control i.e. the amplifier’s ability to reproduce accurately the leading edge of a note’s attack and its ultimate decay to nothingness. Whether this is a function of the Moon’s feedback-free design, I can’t say for certain. What I can be sure of, however, is that the W-5 will astonish you with both its speed and articulation of even the most brisk and complex instrumental scoring. Ravel’s brilliant Concerto for Piano in G (Recut Records REC01), with its fleet scoring for brass, woodwinds, percussion and strings, proved revelatory (Ravelatory?) through the W-5. Never before had I appreciated fully the sheer beauty and complexity of this Gershwinesque score. Sublime music and sound courtesy of the W-5.

Associated Components

Analog: VPI Aries turntable, Audioquest tonearm, Benz-Micro MC Gold moving coil cartridge, Black Diamond Racing "Round Things" record clamp
Digital: Theta Data Basic II transport, Theta DS Pro Progeny DAC
Preamplifier: Audible Illusions Modulus 3A with John Curl designed gold MC phono board
Power Amplifiers: Celeste Moon W-5, Sonic Frontiers Power 2
Loudspeakers: ProAc Studio 150
Cables: XLO Type 4 digital cable, D Lin Audio Silver Bullets 4.0 interconnects, Transparent Audio MusicWave Plus loudspeaker cables, Cardas Hex 5C phono interconnect.
Accessories: Echo Busters room treatment products, Lead(less) Balloon turntable stand with Air Head isolation base, Target equipment stands, Black Diamond Racing Mk.III and Mk.IV Pyramid Cones, Nitty Gritty 2.5Fi Mk.II record cleaning machine, Nitty Gritty Pure-2 cleaning fluid, Stylast stylus treatment, 15A dedicated AC outlets.

The W-5 is proof incarnate that an amplifier with a silicon heart is not an inherently grainy or amusical device. The W-5 is, in fact, one of the smoothest, most fatigue-free amplifiers to grace my listening room, edging out even the excellent all-tube Sonic Frontiers Power 2 in this regard. Quite an achievement. Lest it be construed that the W-5’s smooth presentation is due to some form of sonic editorializing, let me assure you that this amplifier will not provide refuge for either poor recordings or substandard upstream components The Moon’s high degree of transparency will, for better or worse, make you acutely aware of the goings on in both the recording and playback chains. The W-5 pointed out emphatically, for example, which of the Classic Records vinyl reissues are indeed classics in a sonic sense, and which are desirable for their musical value alone. Happily, for both the music lover and audiophile, many are both sonic as well as musical gems.

The Moon W-5 threw a wide, deep soundstage, inhabited by lifelike images of instruments and instrumentalists, whose spatial relationships and boundaries were well defined. The W-5 illuminated the soundstage to a degree which at once startled and delighted me. It was as if someone turned the house lights up a notch or two, chasing away the shadows which previously clung stubbornly to the far reaches of the soundstage.

Rhythmically, the Moon was second to none. The swing, swagger and swoon heard on exceptional jazz recordings such as John Coltrane’s Black Pearls (Prestige P-7316), Clark Terry’s Portraits (Chesky JR-2), and Holly Cole’s Don’t Smoke In Bed (Alert Z2 81020) were represented faithfully by the W-5, lending these recordings an almost bouncy, spring-in-the-step feeling which was more than a little infectious. Switching to the Sonic Frontiers Power 2, the music, while still involving rhythmically, lost some of the forward momentum which the W-5 so readily and handily elicited. The W-5’s tuneful and articulate bottom-end presentation was, no doubt, at least partly responsible for its superior rhythmic performance.

While I did, from time to time, feel that the W-5 sounded slightly etched at the upper end of the frequency range, I believe that much of the blame lay at the foot of the chosen source material, whose sonic failings may well have been brought to light by the Moon’s breakneck transient response. The W-5’s refusal to round or soften high-frequency transients, or to present anything less than the last ounce of upper-end extension may, in fact, force you to rethink the status of some of your so-called "audiophile" recordings. Those recordings with a natural tonal balance and a complete absence of hi-fi gimmickry sounded breathtaking through the Moon amplifier. Those which relied on a hyped-up treble response to impress on first listen, or to compensate for failings in the reproduction hardware of the day, were exposed as nothing more than audiophile wannabes by the W-5.

And this may be the only somewhat controversial aspect of the W-5’s performance - whether its lightning quick response and virtually unbounded top-end extension are somehow an artifact of its feedback-free design, or are truthful to the source. I firmly believe it is the latter, although I’m sure there will be those who will disagree.

I could continue to gush about this or that facet of the Moon’s performance which I found to be reference caliber or state of the art, but this product is one which deserves to be heard, not merely written about. Suffice it to say that the Moon W-5 power amplifier is one of very few products which left me craving its musical delights long after the music had stopped. When in its presence, I was elevated immediately to a higher plane of musical awareness and understanding, and for that I am deeply grateful.

The SimAudio Celeste Moon W-5 power amplifier is a stunning product, both musically and visually. Its design and construction reflect John Poulin and SimAudio’s unwavering commitment to the highest level of musical reproduction. John Poulin’s goal to produce a highly musical and competitive, yet relatively affordable, product has most assuredly been met. Indeed, if it can be said that amplifier design is an art, then Monsieur Poulin is a master of the Renaissance.

Celeste Moon W-5 Power Amplifier
Manufactured by SimAudio Ltd.
3275 1st Street, Unit #1 St. Hubert, Québec, Canada, J3Y 8Y6
Phone: (514) 445-0032, Fax: (514) 445-6626,
Price: CDN$4799
Source of review sample: Manufacturer loan
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