October 1, 2009

Simaudio Moon i.5 Integrated Amplifier


There are all sorts of philosophies regarding integrated amplifiers. In the 1960s, when my addiction to audio first emerged, the top stereo integrateds from H.H. Scott, Fisher, and McIntosh featured every kind of control under the sun: separate treble and bass knobs for each channel, inputs for things like "tape head" (a low-level signal from a tape recorder’s play head), and all sorts of equalization curves. Nowadays, some integrateds, such as Blue Circle Audio’s GDC (review in the works), go the opposite route, with only a three-step input selector, a volume control, and a power switch. Though not quite so spare as the GDC, the Simaudio Moon i.5 ($1200 USD) leans toward the latter approach.


The Moon i.5 matches the appearance and dimensions of Simaudio’s Moon CD.5 CD player: 16.875"W by 3.5"H by just over 13"D. The review sample had an attractive champagne/silver faceplate of thick, extruded aluminum, but the i.5 is also available in black. At the lower left is the standby switch. Depress it and a blue LED above it lights up, signifying that power has been applied to the entire circuit. To the left of that are six pushbutton input selectors, all for line-level sources. The associated jacks for five of these are on the rear panel; the sixth, marked MP (Music Player), is connected to a 1/8" tip-ring-sleeve (TRS) stereo jack at the right of the front panel, for use with an iPod or other such device. Continuing to the left are the Mute and Speaker Off switches. On the right side of the front panel are the sizable (and silky-smooth) volume control, the MP jack, and a standard 1/4" stereo headphone jack.

As with the CD.5, the i.5’s On/Off switch is on the rear, next to the three-prong IEC power receptacle. There are five sets of inputs and one pair of Pre Out jacks, all RCAs. The Pre Out jacks can be used to directly drive another power amp (such as that in a powered subwoofer), their levels controlled by the i.5’s volume control. Note that the i.5 reflects the realities of 21st-century audio by omitting the tape-monitor connections and controls of models built during the days of reel-to-reel and cassette recording. Outputs are a single pair of nice five-way binding posts for each channel. I biwire my main speakers, which meant that doing so with the i.5 required a wee bit of ingenuity; it all worked well.

The compact remote control, which operates both the i.5 and the CD.5, is nicely laid out and was generally a pleasure to use. Most of the remote’s buttons control CD functions. The only amplifier functions offered are Input, Volume (up/down), and Mute. While the remote has buttons for L/R balance, those functions don’t operate with the i.5; as Simaudio’s Lionel Goodfield told me, "at this price point, it would have been virtually impossible to implement a balance control that wouldn’t degrade sonic performance."

According to Simaudio, the i.5 contains "an oversized power supply" that includes a toroidal transformer. Its output is a claimed 40Wpc into 8 ohms or 80Wpc into 4 ohms. Somewhat amazingly, that comes from only a single pair of bipolar transistors per channel. The i.5 is the first amplifier I’ve seen in a long time whose output stages aren’t mounted on substantial heatsinks. Even the output devices of my Linn Majik-1P integrated -- just 33Wpc at 8 ohms -- are attached to an aluminum heatsink. But Simaudio says its all-aluminum chassis obviates the need for a separate heatsink. In my experience with the i.5, its case never became warm, so it seems they know what they’re talking about.

Simaudio recommends at least 400 hours of break-in -- that’s nearly 2.5 weeks, and no way to achieve peace with one’s spouse. However, to put in that time while giving the amp a wide-frequency signal to deal with, I connected a Dynaco FM-3 tuner to the i.5 and fed the amp FM interstation noise (similar to white noise) while feeding the amp’s output to a pair of PSB Alpha Mini speakers, wired out of phase and facing each other to minimize what could be heard in the room. At first, it was mildly annoying; but in short order, we didn’t even notice it upstairs. (The music room is on our home’s lower level.)


As usual, I compared the device under test with my Linn Majik-1P. Input sources were Simaudio’s Moon CD.5 and my Sony CDP-X303ES CD player. I used Linn interconnects with the Sony, Dayton Audio ICs with the CD.5. As is my usual practice, I swapped interconnects during the review period, but could hear no real difference between them.

The Moon i.5 drove my reference floorstanding NEAR 50 Me II or my mid-1970s Wharfedale W60E speakers. For those of you unfamiliar with the Wharfedale, it was considered, in its day, a "bookshelf" model, despite its considerable size (25"H x 14"W x 12"D) and weight (+50 pounds). Each closed-box enclosure contains a 12.5" woofer, a 5" acoustically isolated midrange cone, and a 1.25" soft-dome tweeter. To get their tweeters up to ear level, I place the Wharfedales on homemade 9" speaker stands. The W60E’s bass response, limited to about 40Hz and a little loosey-goosey, is definitely not in the same league as the NEAR 50’s, but its mids and highs are, I think, better than the other speaker’s: lively without being strident.

Both sets of speakers were connected to the amp with 14-gauge AR speaker cable. AC power is supplied by a dedicated circuit operating through a PS Audio Soloist in-wall power conditioner/surge suppressor. My listening room measures 17’L x 11’W x 7’H and is finished in drywall (with makeshift wall treatments) and cork flooring, most of the latter covered by a 9’ x 12’ rug. The speakers are about 6’ feet apart, 26" out from the front wall, at least 2’ from any sidewall, and 6’ from my chair.


In a John Pizzarelli mood when I began my serious listening, I reached for Dear Mr. Sinatra (CD, Telarc CD-83638), in which Pizzarelli is accompanied by the Clayton-Jackson Jazz Orchestra. I listened to "Ring-a-Ding-Ding" -- possibly Sinatra’s ultimate Rat Pack-era tune -- and what I heard set the pattern for all of my listening sessions. The i.5 and the Linn were quite in line with each other in the mids and highs, but the i.5 offered bass response that was just a bit more solid and tight through both the NEAR and Wharfedale speakers. Pizzarelli’s guitar was reproduced with ever-so-slightly more articulation through the i.5 than through the Linn.

There are lots of good female jazz singers these days, and one of my favorites is a still fairly obscure British songstress, Claire Martin. I have several of her albums, but my favorite is The Waiting Game (Honest CD5018). Among the great songs on this CD is Leiber and Stoller’s "Some Cats," originally written for Peggy Lee. Martin’s breathy alto is perfect for the song, and the i.5’s rendition struck me as faster, in that the piano and guitar sounded tighter than with the Linn Majik-1P. The brushed snare sounded incredibly lifelike through both integrateds, but slightly more so via the i.5.

I first encountered Canadian singer Holly Cole on the old CBS TV series Due North. Her performance led me to go right out and buy her Don’t Smoke in Bed (CD, Manhattan CDP 7 81198 2), and I became enamored of her version of "I Can See Clearly Now," a Top 40 hit for Johnny Nash in 1973. Cole’s version features very simple but very syncopated double bass and piano accompaniment, along with her individualistic phrasing. But the precision of the bass line is hard for many amp-speaker combos to reproduce well. Through the Wharfedales, the bass was somewhat sluggish, seeming to lag behind Cole and the piano, and took on a character of one-note bass with either amp. Switching to the NEARs with the Linn alleviated most of the lag, but not all. However, the Moon i.5, in combination with the NEARs, really did a fine job. The mids were very lifelike, and the highs were crisp without being shrill. The bass line was very well articulated, the spare piano accompaniment very lifelike.

Then I played a couple of cuts by the Count Basie Orchestra, both from Count Basie’s Finest Hour (CD, Verve 314 589 637-2); the first was his famous rendition of the Vernon Duke masterpiece "April in Paris." While this 1957 recording is monaural, that mono is gloriously fine, very round and very full. The Linn’s performance was solid; I found myself really getting into it, especially Basie’s exclamations of "One more time!" and "One more once!" as he called on the band to repeat the close. But when I then switched to the i.5, two differences popped up, both in the Moon’s favor: the sound of the trumpets was crisper, more detailed and more rhythmic, while the drums were more articulate. The Moon i.5 made clear just how good a drummer Sonny Payne really was.

By now, I was really enjoying my time with the Moon i.5. It seemed to have that slight extra dollop of rhythm that sometimes escaped the Linn. I’ve always treasured the Linn’s ability to get to a tune’s inner soul. In poker terms, the i.5 saw the Linn and raised it by a factor of x.

I then played "Corner Pocket," also from Finest Hour. In the Basie band, the rhythm section always seems to lag the brass and winds by an eyelash. This, to me, gives each song a forward momentum that has always come through with the Linn -- but the Moon i.5 was just a smidgen better at reproducing that rhythmic tension. Also, the i.5 gave the saxes just a bit of extra bite. I don’t like really "honky" saxes -- I like ’em smooth as honey, and the Basie band offered that in spades. But there’s really smooth (the Linn, like one big sax), and then there’s etched smooth (the i.5, with just enough differentiation to let me know there are several saxes on this track). That etching also came through on the trombones. In all, the rhythm of the group was good with the Linn, but really right with the Moon.

"You Can Call Me Al," from Paul Simon’s Graceland (CD, Warner Bros. R2 78904), has a lot of hard transients -- a punchy bass line, abrupt percussion, even a solo tin whistle. All of those sounded better through the i.5: the bass line had even more staccato punch, and the soundstage was more stable, with instruments placed more firmly on it. The tin whistle stood out just a bit more with the i.5 than with the Linn, and the trumpets and slap bass also acquitted themselves with more resolution.

Another fave is "Money for Nothing," from Dire Straits’ Brothers in Arms (CD, Warner Bros. 47773-2). As I’ve noted in other reviews, in earlier days the beginning of this track made the hairs on the back of my neck stand on end. That doesn’t happen anymore -- I’ve become jaded in my old age -- but when I listened to it through the Sony CDP-X303ES CD player and the Moon i.5, that feeling nearly returned in full. The i.5 was the first amp in some time to nearly re-create the thrill this cut gave me in earlier days, and I consider that exceptional. One thing the i.5 had over the Linn with "Money for Nothing" was its concentrated soundstage: everything -- and I mean everything -- was reproduced within the axes of the speakers. It was rather as if someone had put baffles on the outsides of the speakers to concentrate the sound. Yet each instrument had its specific location, as did each voice. It was a bit freaky. I’d never heard that with any of the many other amps I’ve reviewed, but I think it really fits this recording.


The wonderful thing about audio gear these days is that so much of it is really good. There are many fine integrated amplifiers available in the general price range of the Moon i.5. Some offer more controls, some more power, some offer both, and you’d be hard-pressed to find major fault with any of them. But the Simaudio Moon i.5 has that je ne sais quoi that simply makes it sensational. I wish it had an onboard phono input and a balance control, but those are minor quibbles. The key point is that the Moon i.5 is among the best of the best at its price. If you have a relatively small listening room and/or efficient speakers and you’re looking for an integrated amplifier that sounds really fine, find your local Simaudio dealer and check out the Moon i.5. I believe you’ll find it a delight.

. . . Thom Moon

Price of equipment reviewed