[SoundStage!]Home Audio
Equipment Review
February 2000

Simaudio Moon W-5 Amplifier

by Marc Mickelson

Reviewers' Choice Logo
"Power, authority and sonic
splendor from an amp that can
drive any speaker around and
doesn't cost a fortune."




Review Summary
Sound Power and authority aplenty; bass that's "very deep and tight and displays oodles of slam"; treble is very slightly reduced at its very topmost frequencies, imparting a friendliness to the sound; "on the lean side of things" overall.
Features Input via RCAs (two pairs, one phase inverted) or XLRs; 175Wpc output with huge reserves.
Use Runs cool and free of noise; try an ESP The Essence power cord for sweeter sound.
Value "Given its sonic acuity and price, I would go so far as to say that it's a bargain in terms of high-power, high-quality amps.

Power corrupts, or at least that's what we SET enthusiasts believe, and we may have good reason. There is something about those low-powered amps that makes listening to music through them so very engaging. Some point to the midrange and its palpability, and others mention the treble and its sophistication. Nobody mentions the bass, but we're all willing to compromise as long as we get enough of a low end to not feel completely cheated. Quality over quantity is the mantra, and what a SET amp lacks in juice it makes up for with involvement.

But then you encounter an amp like the Simaudio Moon W-5, which is the antithesis of single-ended triode amp, at least in theory. It's a big, beefy solid-state bruiser that laughs at all speaker loads and can fill practically any room with stupidly high SPLs. It has no tubes to replace -- or fret over -- and gives you a new look at the dynamic capabilities of your speakers and other electronics. It can belt out the sound, but the question still remains: Can it play music? Read on for the answer.

Inside the box

The Moon W-5 is a class-AB, no-overall-feedback design. Dual mono in configuration, it is a rather large amplifier measuring 19"W x 7.5"H x 19"L and weighing in at 70 pounds, most of its bulk toward the front of the amp, which is where its transformers are situated. Like other Simaudio equipment, the W-5 has a unique chassis whose main feature is a set of four "towers" with cones affixed that reportedly help with resonance and micro-vibration control. Around back are the single-ended and balanced inputs, good-quality gold-plated binding posts, an IEC receptacle for a separate power cord, and the power switches. To turn on the W-5, you flip the labeled power switch, wait a few seconds, and then push the reset nub on the back of the amp. It takes a few minutes to figure this out (at least it took me a few minutes), but it's easy to do once you know about it. On the front of the amp is a very thick faceplate -- it looks like it could stop a mortar round -- whose only features are a Moon emblem and small power LED. My review sample came in the grayish/violet (to my colorblind eyes) hue, but black is now the standard finish and looks very dramatic. The W-5 ran cool, even after being on for hours, and exhibited no hum or other internal noise whatsoever.

The W-5 has two sets of single-ended inputs, one that's in phase and another that's not. If your preamp inverts phase, as many tubed units do, you can connect it to the W-5 and not have to worry about adding a phase inversion somewhere else in the chain to compensate.  This is a nice touch.


I used the Moon W-5 in my reference system with my standard lineup of equipment: ProAc Response Four speakers, Lamm ML2 amps and L1 preamp, Timbre TT-1 2000 DAC, JPS Labs cables and power cords. As CD transports (and players), I used a Linn Ikemi or Mark Levinson No.39 as well as a Pioneer DV-525 DVD player. I also used Tara Labs Air One interconnects and speakers cables and ESP The Essence power cords, which worked extremely well with the Simaudio amp (more on this later). For a brief time, I drove Silverline Audio Sonata and Sonatina speakers with the W-5 in addition to my big ProAcs. I also had the Simaudio P-5 preamp and Audio Aero Capitole power amp on hand, both of which I've reviewed previously.

Authority figure

First and foremost, the Moon W-5 is a very powerful amplifier that controls a speaker, imposing its will on the highest treble and especially into the bass. More than any other amp I've had in my system, the W-5 grabs a speaker and tells it what to do. I thought at first that this was an artifact of my many years of tube worship, but then I remembered the many solid-state amps, and high-power ones at that, I've had in my system. None that I can remember had as much command and overall power -- to the point of making my ears call uncle at nothing approaching its maximum power level -- as the W-5. It's rated at 175Wpc, but I would easily believe that its rating is many times this, and it probably is into loads lower than 8 ohms. In fact, Simaudio has reported that the W-5 can put out bursts of nearly 1500Wpc into 1-ohm loads, and I believe them.

Jeff's Take

I auditioned the Simaudio W-5 amplifier in my reference system for just over a month. Marc Mickelson asked me to listen to it in my system due to my experience with some of the finest solid-state amplifiers available. I’m glad to report that my time spent with this Canadian powerhouse was enjoyable as well as enlightening. It was enjoyable for the sheer ease of presentation that never failed to present music in natural, neutral terms, and enlightening due to the W-5's strengths in soundstaging and focus.

The W-5 amplifier is sonically balanced like few amplifiers I’ve heard. It is extended at the frequency extremes without any unnatural highlighting. This characteristic seems to offer a good balance between the sweetness that many find in tubes and the neutrality offered by today’s best transistor designs. The etching that many poorly designed solid-state amps exhibit is absent. The Mark Levinson No.335 is still more transparent, and the Threshold S550E has the edge in midrange clarity, but the W-5 will leave you with the sense that everything is sonically in its proper place.

Now for the best part: Soundstaging is properly scaled with images placed precisely within a three-dimensional field. The images don’t wander either; they are rock-solid. This inspires confidence, especially at raucous volume levels. The W-5 never chokes up, regardless of program-material complexity. Its control is surely a testament to the well-implemented power supply, which bodes well for those with bass drivers that need an iron fist.

Overall I found the Simaudio amp a pleasure to listen through. Its strengths don’t immediately stand out; such is the overall excellence attained. Some other amplifiers edge the W-5 in specific areas. The overall balance of this unit, though, makes for a pleasurable, musical experience that promises long listening sessions and little to fault. At the price, $4795, the W-5 is an excellent value in high-end amplification and worthy of the Soundstage! Reviewers' Choice designation.

...Jeff Fritz

But volume and control are not reasons to buy an amplifier for enjoying your favorite music or we'd all own professional units. In terms of its sonic character, the W-5 reminds me loosely of the various pieces of Linn equipment I've heard, but it has greater low-end authority and guts. Its sound is supremely clear and free of grain, slightly friendly but not so much so that you will notice right away, and doesn't have any of the roundness or fullness of tubes. In fact, the W-5 is on the lean side of things, and this is a consideration with certain pieces of equipment (and recordings) that are this way to begin with. The Presidents of the United States of the America [Columbia CK67291] rocks with the W-5 in use, but heard over the Silverline Sonatina speakers, it sounds disembodied too. Thus while the W-5 will drive most speakers known to man, you will want to mate it with the right speaker. My ProAc Fours sounded terrific with the W-5, and I suspect other ProAc models would perform just as well. Simaudio is the Canadian agent for Dynaudio, so a pair of Confidence 3 or 5 speakers would probably also be an excellent match for the W-5.

Speaker choices aside, the W-5 itself does many things that are truly first-rate and consonant with the music. Its low end, first of all, is very deep and tight and displays oodles of slam -- the holy triad of high-end bass all in one. My ProAcs have a pair of 9" ATC woofers, and some amps, namely of the tube variety, don't control the woofers very well. Other amps did a good job that, after hearing how the W-5 takes charge, now gets downgraded to reasonably good. On Keith Richards' Main Offender [Virgin V2-86499], which has very realistic-sounding bass guitars and drum whomps, the W-5 differentiated the various elements that make up the lowest frequencies with ease, never sounding plump or loose in any way. On "Worlds of Wonder," the bass guitar can shake the beams in some rooms, but in my medium-sized listening room (13' x 20'), the bass just purred and growled with authority and no overhang or unwelcome frothiness. If you are looking for an amp to control the bass of your speakers, perhaps in a bi-amp setup, run out and borrow a W-5.

But the W-5 is not just a bass amp. Its soundstaging is very fine. It offers tremendous depth and width, and imaging is precise, the W-5's ability to cast very distinct and singular images being better than I've heard from any amp. I'm not exaggerating when I say that the W-5 has pinpoint imaging, but the space between the performers is not prominent, perhaps because the images themselves, their solidity, overshadow this. The W-5's sense that the sound pans in front of you in a continuous manner is not up to that of the Lamm ML2s, which are as different from the W-5 as any amp can be. But then the Lamm amps don't carve out the images as well either, so take your pick. In any case, the W-5's ability to suspend belief is very fine, and I know that my observations in terms of its soundstaging are tainted by living with an amp that does it very differently.

Tonally the W-5 is exceedingly neutral, and this translates into a very clear picture of the signal fed to it. But don't let this fool you into thinking that the W-5 may lean toward the grainy, etched end of the spectrum. Its treble, like that of the companion P-5 preamp, seems very slightly diminished in energy, which doesn't impart the last iota of air you will hear from your recordings, but it also doesn't impart a sonic character that you will hate in a week or month. One day during the review period I received a shipment of discs from the Columbia House Music Club. Whoopee! A musical goodie box! My notes from the listening that followed tell the story. Piano on The Ben Folds Five's The Unauthorized Biography of Reinhold Messner [Sony CK69808] was "reproduced well, but doesn't have the last, ultimate bit of shimmer. Transient attack is very fine -- not etched but very quick nonetheless." Regarding the Columbia/Legacy remasters of the Stevie Ray Vaughan catalog: "Easily illuminates the merits of these remasters: improved inner detailing and bottom end." I remember a couple of times opening my eyes (yes, I listen with eyes shut) in quick reaction to the controlled thump of the bass. "Very cool," say my notes. Finally, on Liz Phair's whitechocolatespaceegg [Matador/Capitol 53554], I wrote: "The Simaudio amp lets IT through. The Audio Aero Capitole is more spacious, so there's seemingly more 'thereness,' but the W-5 is no slouch."

One note about power cords. Although the W-5 sounded acceptable with its stock cord, you should experiment. And in this regard, try ESP's The Essence power cord somewhere along the way. Of the various cords I have around here, including ones from API, JPS Labs, and Audio Magic, the ESP cord was the best match with the W-5, adding a bit of sweetness to its overall character. The same recommendation holds true for the P-5 preamp -- give The Essence a try.

From memory

The most recent solid-state amp I've had a personal encounter with is the Lamm M1.1, which is, to be fair and accurate, a hybrid that employs both solid-state circuitry and a single 6922 tube per chassis. Those amps, which are also monoblocks, have tremendous drive and control too, but even they give way to the W-5 in these areas. The M1.1s' treble is extended and very smooth, the W-5's extended but slightly reduced at its uppermost extremes. In terms of body and midrange splendor, the Lamms win hands down given the W-5's slight leanness. Bass is a toss-up, but not because both amps do it in similar fashion. The M1.1s offer more bass weight, the W-5 greater tightness and impact.

Now for the final arbiter: the M1.1s cost over $15k per pair, while the Simaudio Moon W-5 costs under $5k by itself. Hear them both if you can afford them, but if you can't, the W-5 is a more than worthwhile audition. In fact, given its sonic acuity and price, I would go so far as to say that it's a bargain in terms of high-power, high-quality amps.


From my description of the Simaudio Moon W-5, you can probably discern that it seems like the perfect amplifying device. It offers tremendous control of a speaker, especially through the bass region, and never seems to run short of power. But is it the perfect amp for music? If you value that control and huge power reserves along with a character that won't chase you from the room but is not classically musical or accurate to a fault, you will admire the W-5. I know I do. And what may turn your admiration into love is the way the amp delineates images and ultimately produces great sound in the service of your music. As I used the W-5 with a wide variety of partnering equipment, I never felt the need to swap it for another amp when I had some time to unwind and listen for pleasure. In fact, the W-5 made me pull out discs I hadn't heard in a long while just to hear what its unique personality could reveal.

The Simaudio Moon W-5 surely competes with monster amps from the bigger-name makers and will beat them at some of their games. It's a brute with soul, and it deserves your attention.

...Marc Mickelson

Simaudio Moon W-5 Amplifier
$4795 USD.
Warranty: Ten years parts and labor.

3275, 1st Street, Unit 1
St. Hubert, Quebec Canada J3Y 8Y6
Phone: (450) 445-0032
Fax: (450) 445-6626

E-mail: :info@simaudio.com
Website: www.simaudio.com

[SoundStage!]All Contents
Copyright 2000 SoundStage!
All Rights Reserved