Simaudio Moon i-5 integrated amplifier
By Chip Stern   •   July, 2002 With this review I conclude an audiophile's progression through the price/performance ratios of three very musical solid-state integrated amplifiers: the NAD C370 ($699, reviewed in January 2002), the Arcam DiVA A85 ($1499, February 2002), and now the Simaudio Moon i-5 ($2595). In the process I was fascinated to hear how each amp recommended itself to its targeted price point. Likewise, it was most instructive to hear how they spread their compromises around. With a rough doubling of suggested retail price from the NAD to the Arcam, there was a degree of sonic refinement introduced. However, the leap in improved sound from the Arcam to the Simaudio was more significant. And in quantifying the benefits another $1000 worth of enhancements can confer, I discovered what constitute real high-end bona fides.

Design Integrity: Value You Can Hear
One of Simaudio's fundamental design considerations in crafting this no-compromise integrated amplifier was mundane enough: to use the same chassis as other Moon separates, such as the P-3 and P-5 preamps, the Air Analog FM tuner, and the Eclipse CD player that Brian Damkroger favorably reviewed in April 2001. The Moon i-5's slender, unobtrusive chassis is rigid, which adds to the unit's mechanical grounding and, in conjunction with four support cones, helps decrease the i-5's sensitivity to mechanical vibrations. But while the inherent stability of this chassis provided certain structural benefits, it also imposed some limitations on the configuration and array of features Simaudio's engineers could offer.

"Of course, the limitations of the i-5 are matters of space," explained Lionel Goodfield, Simaudio's VP of marketing and media relations. "Our design was motivated by the desire to pop everything into a single chassis. That's why we have only five sets of inputs—although those RCAs and our WBT binding posts are high-quality components—and why we didn't entertain the option of gain matching the output stage to another one of our amps in the event you wanted to consider the possibilities of biamping. That would have required jamming way more circuitry into that limited amount of space, which is also why we don't offer a headphone circuit or an onboard phono stage—we didn't want to compromise the sonic performance. Because if we can't do it properly, why bother?"

Still, the i-5 amp features a bevy of performance enhancements that should preserve its value for years to come—like pure-copper circuit-board traces and careful matching of electronic components. The i-5 employs a short, capacitorless signal path of only 15", and while it uses a touch of global feedback at the output stage, the i-5 is, overall, a no-feedback design that delivers what Goodfield calls "real-time amplification for exceptional speed and tonal accuracy."

While the Moon i-5 is rated conservatively at only 70Wpc into 8 ohms, that figure is deceiving: its power supply, based on a proprietary toroidal transformer, is said to provide abundant reserves of current. "And you'll also notice that it doesn't get real hot," Goodfield pointed out. "That's because of the way it's biased in terms of the transformer and power supply—we're not pushing the internal circuitry to its limits."

Nice and Easy Does It
Having lots of Teflon parts and heavy copper wiring means that the Simaudio Moon i-5 takes an inordinately long time to break in—and the absence of capacitors in its signal path meant that I heard each and every awkward aspect of that transformation. At first, the bass seemed a bit diffuse and unfocused, the highs too laid-back and lacking absolute detail and air, and the midrange lacking in coherence and depth. In a word, bland.