April 1, 2008

Simaudio Moon Evolution P-7 Preamplifier and W-7 Stereo Amplifier

A little over a year ago, I reviewed Simaudio’s Moon Evolution i-7 integrated amplifier, the best integrated amplifier I’d ever heard. I thought so much of it that it not only received a Reviewers’ Choice designation, but also our SoundStage! A/V 2007 Product of the Year award. Since then I’ve reviewed the Moon Evolution SuperNova CD player, which impressed me nearly as much, and the Moon i-1 integrated amplifier and Moon CD-1 CD player (for GoodSound! and SoundStage!, respectively), the Classic models being "entry-level" electronics that deliver far more than a glimpse of Evolution-level performance at a fraction of the cost.

Now, finally, I’m reviewing the Moon Evolution P-7 preamplifier ($6900 USD) and 150Wpc W-7 stereo amplifier ($8900), which are second from the top of Simaudio’s line. (Above them are the two-chassis Moon Evolution P-8 preamplifier and 250Wpc Moon Evolution W-8 stereo amplifier, each $13,500. There’s also the Moon Evolution W-7M, said to deliver 500W into 8 ohms for $10,000, or $20,000/pair.) Combined, the P-7 and W-7 are more than twice the price of the i-7 integrated (now $7200). Hardly cheap -- but, as you’ll see, quite remarkable, and well worth the price.


The Moon Evolution P-7 is a dual-mono, fully balanced design that includes pretty much everything Simaudio knows about preamplifiers. Simaudio’s purpose in creating the P-7 was to squeeze every bit of performance they could into a single box. (The P-8 comprises two chassis: one for the power supply and controlling circuitry, the other for the audio circuits.)

The P-7 looks just like the i-7, is the same size (19"W x 5.5"H x 16.5"D), and has the same high quality of construction and parts. It comes standard with a silver or black faceplate, silver "cheeks" (black is an option), and chrome cone feet (gold is an option for these). In fact, a P-7 could easily be mistaken for an i-7 -- until you picked them up. The preamp-only P-7 weighs about 35 pounds, the i-7 integrated closer to 60.

The i-7 and P-7 are also similar in operation. Each comes with Simaudio’s club-like, all-aluminum FRM-2 remote control, and has a brightly lit display (it can be dimmed or turned off) that not only lets you know such things as which input has been selected and what the volume setting is, but also serves as the "configuration gateway" (my term) to all the features that lie behind it -- as many as any audiophile will likely need. For example, by using the buttons on the front panel and looking at the display, you can rename, adjust the level, and set the maximum volume for each input, and designate certain inputs to bypass the volume control entirely. That last feature is included to accommodate a surround-sound processor, whose stereo output can be passed through the P-7 to the amplifier with as short and clean a signal path as possible. And if you don’t want to use an input, you can disable it altogether -- handy for when you want to cycle forward or back through the inputs and don’t want to hear dead air.

The volume controls of the i-7 and P-7 seem identical. Each changes the signal level in increments of 1dB from "0" to "30," and in 0.5dB increments from "30" to "80." The numbers themselves are arbitrary, merely indicating where you are on Sim’s "digital scale": coarser adjustments at lower volumes, finer ones when you get into the normal listening range -- just what you want for dialing in the right volume level. Most people will find those increments fine enough, but it’s worth noting that the P-8 outdoes the i-7 and P-7 by offering increments of only 0.1dB above "30," which allows for really fine adjustments.

The inputs on the i-7 and P-7 differ a bit. The P-7 has four single-ended inputs and two balanced inputs, whereas the i-7 has five and one, respectively. I prefer having two balanced inputs -- two of my source components are balanced, and with the i-7 I was forced to use a single-ended input for one of them.

The P-7 has one pair of balanced outputs (labeled V2) and two single-ended pairs (V1 and F). The latter require a note of caution. Outputs V1 and V2 are attenuated by the volume control. Provided the volume is turned down, you won’t get a burst of power when it’s selected and the music starts playing. Output F, however, is not attenuated by the volume control, but bypasses it altogether. If you hook up your power amp to that one, you’ll be feeding the preamp’s full output to the amp and thence to the speakers -- which could blow up your speakers. I didn’t use Output F, but Simaudio must have included it for some reason -- likely for use with amps that have their own volume controls. So be careful.

On the rear panel of the P-7 you’ll also find a SimLink connector, which allows you to chain together multiple Simaudio components with a supplied cable so they can communicate with each other for quicker, easier operation. (SimLink is now included in all of Sim’s newest components, including the entry-level i-1 and CD-1.) There are also a 12V trigger connector, a jack for an infrared remote control, and an RS-232 port for a custom-installation setup.

The W-7 is a dual-mono stereo amplifier with 12 bipolar output transistors per channel and is said to deliver 150Wpc into 8 ohms, 300Wpc into 4 ohms, or 600Wpc into 2 ohms. It can also be bridged to operate as a monoblock amplifier that will output 600W into 8 ohms. Power-wise, the W-7 is a beast, delivering more power than most users will ever need. And the way it can "double down" into lower impedances indicates outstanding current capability; it’s unlikely to be tripped up by speakers of lowish impedance.

It’s a powerhouse, but the W-7 isn’t all that big: 19"W x 7.5"H x 16.5"D. Still, it’s heavy -- about 80 pounds. Much of that weight is attributable to its two large transformers, the beefy parts used throughout, and the well-built enclosure. Cosmetically, the W-7 matches the P-7 and everything else in the Evolution line, with the same cosmetic options: black or silver cheeks, chrome or gold feet.

A recent back injury caused me some concern with the W-7 -- moving it around wasn’t easy. Furthermore, the pointy cones Simaudio supplies as feet to keep their equipment stable were a bit of a hassle when it came placing the W-7 on my equipment rack. Something that heavy with feet that sharp is likely to scratch something -- in my case, the bottom shelf of my equipment rack. You might need a friend to help you unbox your W-7 and get it into place.

On the W-7’s rear are pairs of single-ended and balanced inputs. There’s also a SimLink connector, a 12V trigger connector, an RS-232 port, and the main power switch, which is intended to be left on at all times. For day-to-day operation, there’s a Standby switch on the front for power-up.

The P-7 and W-7 functioned flawlessly the entire time they were here -- as had the i-7, i-1, SuperNova, and CD-1 before them. This speaks well for Simaudio’s strong track record of reliability and good build quality across their product line. No wonder they back their stuff up with a ten-year warranty, instead of the five-, three-, or even one-year warranties common in the industry today.


Sometimes, certain electronics -- mostly power amplifiers -- work well only with specific speakers. I found the Moon Evolution combo of P-7 and W-7 so neutral and so refined, and the W-7 so powerful and well-behaved, that I had no trouble using them with all the speakers I had on hand: PSB Synchrony One and Two B, Paradigm Reference Signature S1 v.2, KEF Reference 201/2, Dynaudio Confidence C1, and Mirage OM Design OMD-28.

For the bulk of my critical listening I used the Moon Evolution SuperNova CD player with the P-7 and W-7 together. Interconnects were always balanced versions of Nordost Valhalla, and speaker cables were usually Nirvana S-L.

I also used the W-7 with an Anthem Statement D2 A/V processor for a time with no problem whatsoever. Although I suspect that many will buy the P-7 and W-7 together, they’re separates -- you don’t have to pair them. Some may wish to mix’n’match.


The Moon Evolution P-7 and W-7 offered all the performance of the Moon Evolution i-7 integrated -- and then some. All the strengths of the i-7 that I described in my review -- clean, detailed, neutral, revealing, resolving, transparent, etc. -- can be applied to the P-7 and W-7, then underlined. The P-7/W-7 were a little better across the board, particularly in detail and resolution.

I first listened to one of my favorite reference recordings, Mariza’s Transparente [CD, Times Square TSQ-CD-9047]. With it, I heard not only the same kind of breathtaking clarity I’d heard through the i-7, but also a subtly better re-creation of the recorded space, improved delineation among the musicians, a bit more detail in the overall presentation, and a smidgen more presence and fullness without any hint of the singer or instrumentalists being obscured. Everything the i-7 could do extraordinarily well the P-7 and W-7 did subtly better. So I guess the P-7 and W-7 are more extraordinary.

When I played Eddie Vedder’s "Society," from his music for the film Into the Wild [CD, RCA 715944], I heard a spellbinding re-creation of space and depth that seemed to extend past the front wall, presenting a soundstage that seemed to have no real defined bounds. Therefore, the real strengths of the P-7/W-7 combination weren’t just refinement and neutrality -- which the i-7 also has in spades -- but increased detail and resolution. And even though the P-7/W-7 combo was more detailed and resolving than the i-7, it was like the i-7 in never sounding sterile, clinical, or tiresome to listen to. Rather, these components walked the same tightrope as all Moon Evolution components: uncanny neutrality, accuracy, resolution, and complete "listenability." Amazing.

What’s more, while I can usually point out aspects of the performance of any component that are lacking -- there always seems to be something -- with the P-7/W-7 I was flummoxed. There wasn’t a thing I could fault; I was reduced to fretting about the pointy feet that scratched my shelf, or the impressively massive FRM-2 remote -- if you drop it, there’s a good chance it’ll dent a wooden coffee table or smash a glass one. In terms of what’s actually important -- the sound -- the P-7 and W-7 were beyond reproach. In fact, I almost want to say that this is as good as it gets -- the best you can buy.

But I have to remind myself -- and you -- of two things: 1) I haven’t heard everything that’s out there, and 2) the P-7 and W-7 don’t even represent the top of Simaudio’s line. At least in terms of price, the P-7 and W-7 rank below the P-8 preamplifier and the W-8 and W-7M amps. Perhaps they squeeze out a little more -- who knows? I just know that if they do, they sound amazing.

Moreover, despite their identical power ratings of 150Wpc into 8 ohms, the W-7 sounded more powerful than the i-7, although I didn’t necessarily play the music any louder with it. Rather, the greater power I sensed came from the W-7’s greater degree of freedom and effortlessness, regardless of which speakers it was driving. Furthermore, with those speakers I know to be somewhat tough loads -- the PSB Synchrony One and Mirage OM Design OMD-28, both largish floorstanders that can be a bit tricky for some amps to drive -- the W-7 never once winced. It took a tight grip on both speakers and never let go.

When I played the opening two tracks of the Cowboy Junkies’ The Trinity Session [CD, RCA 8568-2-R] through the Mirage OMD-28s, I not only got all the weight and presence contained in that recording, I also got a wealth of detail that immersed me in a stereo soundfield as impressive for its volume and heft as for its tonal accuracy and detail. In fact, people who came over to listen agreed that, in terms of fidelity, the Simaudio-Mirage setup was on a par with the Aurum Acoustics Integris CDP/Active 300B system, which I reviewed for SoundStage! about a year and a half ago, and which remains among the best I’ve ever heard. This doesn’t mean that the two speaker systems sounded the same -- the omnidirectional Mirages disperse their sound over 360 degrees and thus sound quite different from most speakers on the market -- but that they were in the same league of sound quality.

Furthermore, when I went on a hard-rock kick, as I did with the two PSB Synchrony speaker models (the Two B can play impressively loud for its size; the One can play LOUD, period), the W-7 sounded not only effortless but limitless. With the Ones, I reached SPLs so loud that I feared damaging my ears as well as the speakers if I carried on much longer. But there was never any fear of the W-7 giving out -- it delivered power as solid as its physical construction. Although I’m sure there’s a limit to its power output, for all practical purposes I never reached that limit in my listening room.

The W-7 never sounded strained. In fact, it never sounded anything other than glorious. It was as perfect an amplifier as I’ve heard. If I could afford to move up in the Evolution line but wanted to keep a lid on price, before I went to the W-8 or W-7m just to get more power, I’d consider the P-8 preamp, if only because it boasts 15dB greater signal/noise ratio; if true, that means even greater resolution. On the other hand, if my speakers gave the W-7 trouble, I might change my mind. Time will tell.

The i-7 impressed me enough to redefine my benchmark of performance for an integrated amp. The combo of P-7 and W-7 impressed me in just the same way, establishing for me a benchmark at which separates at these prices should perform. They did everything the i-7 does, but just a little better. That’s not to knock the i-7 -- remember, its price is less than half that of the P-7 and W-7, which makes it the slightly better deal: it gets you most of the way there. But as good as the i-7 is, you can do better; if you’re willing to pay what it takes to get almost everything, the P-7/W-7 combination will deliver it.


Anyone who has the money to invest in Simaudio’s Moon Evolution P-7 and W-7 will not only be buying some of the best audio components out there, they’ll then own something that will last them for many years. They’re built extremely well; every Simaudio product I’ve reviewed in the last 13 months, including these, has worked flawlessly; and Sim backs all its equipment with a ten-year warranty.

But those aren’t the only reasons for keeping a P-7 and W-7 in your system so long. The best reason is their sound. These Moon Evolutions perform to such a high standard that I don’t see them being, er, eclipsed for years to come, at least not at this price -- not until the next, um, evolution in audio comes along. If there’s better out there, it’s got to be phenomenal, and it’s more than likely to be a lot more expensive. The performance of the Simaudio Moon Evolution P-7 and W-7 is nothing short of spectacular. Very highly recommended.

…Doug Schneider

Simaudio Moon Evolution P-7 Preamplifier
Price: $6900 USD.
Simaudio Moon Evolution W-7 Stereo Amplifier
Price: $8900 USD.
Warranty (both): Ten years parts and labor.

Simaudio Ltd.
2002 Ridge Road
Champlain, NY 12919
Phone: (877) 980-2400, (450) 449-2212

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


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