March 1, 2007
Simaudio Moon Evolution i-7 Integrated Amplifier
Ive been reviewing audio equipment for more than ten years, and in that time have seen and heard so many components that I rarely get excited about much anymore. Thats not to say that all this equipment has become ho-hum -- its just a byproduct of having seen so much stuff.
So, when I was asked to review Simaudios Moon Evolution i-7 dual-mono integrated amplifier, I didnt have to hide my enthusiasm -- I had none. Its hard enough for me to get excited -- and harder when its a solid-state integrated amplifier. Could anything be more boring? Couldnt it at least be a combo of preamp and power amp? After all, separates are usually much more interesting, and they often perform better to boot.
Anyway, thats what I thought -- until I hooked up the i-7 to my system and heard it play music. In an instant, I went from bored to elated, and thought, Do I really need separates at all?
Simaudios Lionel Goodfield told me that it took more than two years to develop the i-7. The reason, likely, is that this integrated amp couldnt be merely good enough -- its part of their Moon Evolution series, which comprises the companys best products. At $6000 USD, its the most expensive integrated amplifier Simaudio offers, and the only one in the Evolution series. Above the i-7 are only separates: the P-7 and P-8 preamplifiers, and the W-7, W-7M, and W-8 power amplifiers.
When designing the i-7, Simaudio wanted to ensure that it was sufficiently powerful, as well as truly high-end in terms of sound and build quality. They claim it delivers 150Wpc into 8 ohms or 250Wpc into 4 ohms -- enough for most applications. As well, it measures 18.75"W x 5.5"H x 16.5"D -- big but not huge -- and weighs about 55 pounds. The i-7 is a dual-mono design, meaning that except for the single power cord, the circuitry inside is not shared between channels. Simaudio also says that the i-7 is fully balanced throughout, something that requires exceptionally careful matching of internal parts.
Furthermore, the i-7 was designed to be rich enough in features while still being easy to use and of a manageable size. That means that Simaudio has omitted some superfluous items and instead concentrated on doing a superb job of implementing features owners will really use. As a result, youll see a number of buttons and connectors on the i-7, but not so many that you get lost in a jungle of clutter. Chances are youll use almost everything thats there and wont want more.
On the rear are five sets of single-ended RCA inputs and one XLR balanced input. There are also gold-plated WBT speaker-cable binding posts, an IEC receptacle for a detachable power cord (Simaudio supplies a thick black one), and a main power switch. There are also tape loop and line-level outputs, both with single-ended RCA connectors.
There were a few connectors I didnt use, though some owners undoubtedly will. One is a 12V trigger to turn the amp on remotely. Another is an RS-232 port for control in a custom-installed system, as well as in-the-field updates to the i-7's firmware. Theres a 1/8" mini-jack for a third-party infrared remote control, and finally, Simaudios proprietary SimLink port so the i-7 can communicate with other Moon components.
Turn the i-7 around and youll see its sturdy yet stylish front panel. The anodized-aluminum faceplate, available in black or silver, is about 3/8" thick in the center and more than 1/2" thick toward the rounded sides (which Simaudio calls "cheeks"). Its exceptionally well finished, and theres the nice touch of being able to customize the look. The standard i-7 comes with a silver or black center faceplate, silver cheeks, a red display, silver footers, and a chrome logo. You can also get black cheeks, a blue display, gold footers, and a gold or pewter logo. These are small touches, obviously, but Im sure some people will go for them.
The spare front panel showcases the elegance of the design. Theres a large volume knob on the right, and flanking each side of the large, central LED display are four buttons. The two on the left are Standby, for day-to-day powering up of the i-7 when the main switch on the back is already engaged, and Display, which lets you adjust the brightness of the LED readout to medium, high, or off. On the right are a Mute button and a Monitor switch, for the tape loop. Channel balance is available only via the remote control (described below).
Below the display are four more buttons. The leftmost two are for input selection. The one with the "+" over it lets you cycle through the inputs forward (B1, S1, S2, S3, S4, S5), the "-" button in reverse order. The two buttons on the right, labeled Setup and OK, are what I think of as the "gateways" to customizing the i-7 to your exact needs. This is because, behind this rather spare faceplate, many of the i-7s features are software-controlled, and these buttons are how you access them. (The OK button is the equivalent of a computer keyboards Enter key.)
You can press Setup to rename the inputs, perhaps to the associated components names or model numbers (B1, S1, etc., are the factory defaults). You can also trim each input by +/-10dB in increments of 0.5dB, which is incredibly handy for matching the levels of source components. I used this when I was using the i-7 to compare DACs, the output of each of which was different. Furthermore, if a source component (a processor, for example) has a volume control, you can program any input to bypass the i-7s volume control, meaning a full-level signal is then sent through the i-7 just as if the component were directly hooked up to the power amp. (Warning: Bypass the i-7s volume control only if the source has a volume control and its turned all the way down; otherwise, you could send the full output of a source component through the amplifier section and blow up your speakers.)
There are other things you can customize as well, but I wont waste time on all that here. One truly handy feature of the Evolution i-7 that I do want to point out is something that is now, finally, appearing in more and more designs: maximum volume setting. Ive wanted this feature ever since the mid-80s, when I watched an audio salesman scratch his head with frustration as he tried to figure out why a system hed set up wasnt making any sound. He pushed this knob and that knob, and repeatedly increased the volume level. By the time hed figured out that the correct input wasnt selected, the volume control was pegged all the way to the right. The music blared through so loudly that he blew out the $8000 pair of speakers he was hoping to demo. The i-7 lets you specify a maximum level setting in dB so that that cant happen.
And speaking of that volume control -- its not your everyday ol volume knob. Simaudio calls the guts behind it M-eVOL, though Im not sure exactly what those letters stand for. According to Simaudio, when you turn the volume control, it engages a "precision optical encoder which selects very high quality metal-film resistors that the audio signal passes through." In other words, theres no mechanical coupling to a resistor stack. In addition, Sim claims that their control doesnt degrade the signal, that it operates in a "fully balanced differential mode" so that "no noise is introduced to the audio signal," and finally, because there are no moving parts except for the rotating knob itself, the controls lifespan is "one million rotations." So spin that volume knob all you want, without fear that it will wear out.
I played with the volume control a lot and liked the increments Simaudios chosen for it. Its full range is from 0dB (muted) to 80dB (full power): from 0dB to 30dB, the increment is 1dB; however, from 30dB to 80dB, the increment is 0.5dB if you turn the knob slowly, for fine tuning, but 1dB again if you turn it more quickly. It worked perfectly for me.
I liked the remote control, too, although its a little club-like and heavy. Its Simaudios FRM-2 remote, which they ship with most of their products. Milled from a solid block of aluminum -- no cheap plastic thing here -- it has the basic preamplifier controls (Power, Volume, Balance, Mute, Input select) as well as the basic functions (play, stop, pause, skip, scan, repeat track) for Simaudio CD players and other players with Philips-based transports (which I discovered when it also controlled my Theta Data Basic transport). The FRM-2 worked very well, but its not something you can just toss around.
All in all, the i-7 is a serious piece of audio machinery that combines great build quality and styling with a strong feature set. Simaudio caps it off with a ten-year warranty -- not the longest in the biz, though twice the industry norm. But none of that was what thrilled me about the i-7. Rather, it was the sound -- or lack thereof.
I used the Moon Evolution i-7 with my Theta Data Basic transport and three different DACs: Stellos DA220 and newer DA220 Mk.II, as well as the Slim Devices Transporter (a killer!). Speakers were the Mirage OM Design OMD-28 ($7500/pair), Focus Audio Master 2.5 ($18,590/pair), and YG Acoustics Anat Reference Main Module ($28,000/pair). Digital cables were i2Digitals X-60 and DH Labs Silver Sonic D-75. Interconnects were Nordost Quattro-Fil, singled-ended and balanced, and speaker cables were Analysis Plus Silver Oval (Focus Audio, YG Acoustics) and Nirvana S-L (Mirage).
One thing I liked right off about the Simaudio Moon Evolution i-7 was that it didnt sound wimpy with any of the speakers I tried. One hundred and fifty watts isnt low-powered by any stretch of the imagination, particular for an integrated amp, but these days, it isnt high-powered either. You can get huge power today for very little money if you need it. However, I never did need it -- not once. I never felt that the i-7 was running out of steam, even as I cranked Focus Audios Master 2.5s to the very high SPLs of which those speakers are more than capable.
Moreover, the i-7 had no trouble keeping its grip on even the tough load presented by the YG Acoustics Anat Reference Main Modules. This speaker is reasonably sensitive, but it does require an amp to deliver considerable current: its nominal impedance of 4 ohms can dip down to 2.7 ohms. While the Anats arent necessarily a torture test, I could see some amps having trouble driving them. The i-7 wasnt one of them; it was solid.
But power output and current capability arent what make a great integrated amp these days, particularly one that sells for six grand. Instead, what separates the good integrateds from the great is how they sound -- or, preferably, dont sound. Which is where the i-7 shone -- or didnt.
I was astonished at how transparent and detailed the i-7 was -- more so than any integrated amplifier Id ever heard, and on a par with the best separates you can buy. It was exceptionally clean, wildly uncolored, and, as a result, without a hint of hardness, dryness, steeliness, or brightness -- words that often creep into reviews to describe the sound of some solid-state electronics. There was none of that here -- from top to bottom, the i-7 was superb, with first-rate clarity and resolution.
For example, the Anat Reference Main Modules accuracy is topnotch -- as neutral as almost anything youll find out there. My only caveat is that its a smallish speaker, and so doesnt deliver deep bass (youll need Anats Studio sub for that). But when I coupled them with the i-7 and a good digital front end, I heard recordings in the most ruthlessly revealing way. Unless it was in the deep-bass range, nothing could hide.
Bruce Springsteens Nebraska is considered by many to be, musically, his best album. Sonically, its terrible. He recorded it on a Tascam four-track cassette recorder, and the 1990 CD release [Columbia CK 35358] sounds as if little care was taken in transferring his music into a digital format. Its a seriously bad recording, and using the i-7 to drive the Anat References held back none of the bad news. In fact, Id never heard Nebraskas recording flaws rendered with such clarity. The playback was truly "warts and all."
Thats exactly why I so like equipment like the Anats and the i-7. The best equipment must let everything flow through unadulterated; you should hear whats bad on a recording, along with whats good. This means that when something exceptionally well recorded comes along, such as Marizas Transparente [CD, Times Square TSQ-CD-9047], you can revel in exactly how spectacular it sounds.
Marizas voice came to life with mind-boggling detail, and her accompanists were a snap to pick out of the mix. Furthermore, nothing seemed to get lost with the i-7 -- nothing. All those little reflections and spatial cues were transmitted whole. As a result, the soundstaging and imaging were first-rate -- musicians were well-focused on the stage, and the sense of depth was outstanding
However, thats not to say that the Moon Evolution i-7 is only for those who want to put their music under a microscope. That just happens to be a specialty of YGs Anat Reference Main Module; the i-7 itself was so transparent and so unmistakably uncolored that it was well qualified to join such a system. In fact, more recording engineers should use equipment like this so that they can hear what their recordings really sound like.
Still, the i-7 is not only a lab instrument; its uncolored nature made it a chameleon, suitable for use with every loudspeaker I had on hand. When I hooked it up to the Focus Audio Master 2.5s and Mirage OM Design OMD-28s -- speakers that are resolving enough, but are more concerned with creating a presentation of appropriate size and scale that includes truly deep bass -- the Moon slipped in perfectly to play the same transparent, uncolored tune it had with the Anats. Dave Berger and the Sultans of Swings Hindustan [CD, Such Sweet Thunder SST1004] is a gorgeous-sounding recording that captures an excellent sense of space with a dynamic agility that really helps the music come alive. Played through appropriately sized speakers and an amp as capable and uncolored as the i-7, it really does sound as if a large band is filling the room.
Two years ago I reviewed the DK Design Group VS.1 Reference Mk.II integrated amplifier (since superseded by the VS.1 Reference Mk.III, $3200). Though it had a tube-based input stage, the VS.1, too, was a big, beefy integrated amplifier with a solid-state output stage and a claimed power rating of 150Wpc into 8 ohms. Its most impressive feature, however, was its price, $2995, because it sounded so good and was built as if it should sell for twice as much. Some nonetheless criticized that price, because it's well known that although DK Design Group is US-based, the VS.1 was manufactured in Asia. But thats now commonplace in high-end audio, and I cant necessarily take into consideration place of manufacture when assessing a products value. When it lands in a store with a certain price tag, it is what it is. The VS.1 Reference Mk.IIs sound quality was impressive enough that you could say it approached the sound of high-quality separates. Which made it a great integrated amplifier for the money. Which is why it got our Reviewers Choice nod.
Sonically, though, the VS.1 fell short of the top of the heap in some key areas. For example, when compared with an integrated amp or separates with sound thats absolutely pristine -- the i-7, for example -- the VS.1 Reference Mk.II does not sound clean, clean, clean, but a touch coarse. Furthermore, its top end is not as free and airy as the very best. I could pick a few other nits, but they arent things that can be fairly held against a $2995 integrated. For three grand, the VS.1 does a lot of things right. It just isnt the very best you can buy.
The Simaudio Moon Evolution i-7, however, is at the top of the heap, and betters the VS.1 Reference Mk.II in every way. It sounds cleaner, resolves more detail, and even sounds more powerful, although its power rating is about the same. Furthermore, the i-7 has far more features, is built to a higher standard, and looks sharper. Theres not a single area in which the Simaudio isnt superior to the DK -- which, in my books, makes it as good or better a deal, even at twice the price. The VS.1 Mk.II is a very good integrated amplifier; the i-7 is an extraordinary one.
The Simaudio Moon Evolution i-7 is the best integrated amplifier Ive ever heard. I was astonished at the level of transparency it exhibited, and how it conveyed music in such a pristine, unadulterated way. Its also built exceptionally well, and its features worked flawlessly. I would have no hesitation installing it in the finest systems, even pitting its performance against higher-priced separates. And while Im known around here as a practical, commonsense reviewer who prefers to review products priced in the hundreds and low thousands of dollars, and is always searching for the next great deal, the $6000 Simaudio is asking for the i-7 makes it an exceptionally good deal. I know of nothing priced lower that sounds better and is built to this standard.
As Ive said, the i-7 is a chameleon: It does whats necessary by providing sufficient power and allowing even the most minute details of the music to flow through, all while imparting no sonic signature of its own. State-of-the-art and a reasonable price is a rare combination, but its precisely what Simaudio has delivered with this product. I have nothing to criticize about the Moon Evolution i-7 -- something thats never happened in all my years of reviewing. Its that good.
Simaudio Moon Evolution i-7 Integrated Amplifier