Moon by Simaudio 888 monoblock power amplifier

Not everyone needs a power amplifier that can deliver 888W RMS into 8 ohms or 1776W into 4 ohms. You could say that no one needs one of these—or two, if you want to listen in stereo. Most household AC systems can’t even provide enough current to deliver all that power. But Simaudio does build Moon 888 monoblocks, and people do buy them, whether or not they need an amp that weighs about 250 lb each and costs $118,888/pair.

But forget about need. Would you want a pair of these massively heavy amps? People into tubed gear might not, but if price was not a consideration and if you had the room, chances are good that the rest of you would. After listening to a pair in my listening room, I did.

Some months ago, Costa Koulisakis, Vice President–Customer Experience and part owner of Simaudio Ltd., rolled two Moon 888s into my ground-level listening room and, with great difficulty, lifted each off its dolly and plopped both down on my carpeted cement floor. While setting a powerful audio amplifier directly atop carpet is not usually advised, Koulisakis assured me that it would be safe. Each amp’s four big, spring-loaded, self-leveling feet rose to the occasion.

When the Moon 888s were in place, Koulisakis removed the top panel of one of them and gave me a tour. I shot a video of it.

Inside and Out
The Moon 888 is big—22″ wide by 14″ high by 27″ deep—and its construction quality is heroic. It’s so sturdily built that I could safely stand atop one to replace a ceiling lightbulb. (Don’t tell anyone at Simaudio I did that.) The large, extremely heavy top panel is made of cast aluminum, its underside ribbed for extra pleasure—I mean, extra strength—and covered in a vibration-deadening paint.

The cleanly laid-out rear panel offers two sets of easily accessed speaker terminals for biwiring. Below these are single-ended (RCA) and balanced (XLR) inputs (I ran balanced exclusively), a switch for choosing between them, and another switch for selecting AC or DC coupling (see below). Below those are an RS-232 port for automation and updates, a 12V trigger input and output, a 20A IEC power inlet, a fuse, the main power rocker switch, and three warning lights, labeled Thermal, DC Level, and Other.


Each side panel is actually a single large heatsink comprising not a series of bolted-together sections but a single aluminum casting. Simaudio claims that this dissipates heat more evenly, to ensure that all 32 bipolar transistors in this fully balanced, dual-differential amp consistently run at the same temperature. This casting includes a series of channels and indentations designed to control vibrations. Every other part of the case and chassis is machined from aluminum.

If you watch my video you’ll see that high-quality parts are used throughout the 888. The two large, custom-wound transformers have been potted inside large chromed cylinders. The 12 big, custom-made power-supply capacitors in the main storage bank have a total capacity of 324,000µF, augmented by secondary and tertiary storage caps, including one next to the output transistors, for a total of just over 400,000µF—not surprising in an amplifier claimed to double its already impressive specified output each time the impedance is halved.

The Moon 888 can be AC- or DC-coupled via a switch on its rear panel. Simaudio says that DC coupling produces less phase distortion and thus better bass resolution. However, despite the 888’s sensitive DC-detection circuitry and proprietary DC servo, any amount of DC amplified to full power by the 888 would spell certain doom for any speaker hooked up to it. So while Simaudio recommends setting this switch to DC when using a Moon preamplifier, they urge caution when using preamps made by other brands, when AC coupling should be used. I ran the 888s DC-coupled without incident, first using a darTZeel NHB-18NS preamplifier, then a CH Precision L1.

Simaudio themselves make every major part of this amplifier, other than the two pairs of large, clutched, rhodium speaker terminals, which are made in Japan by Furutech. When the speaker cable has been sufficiently tightened, the clutch slips, to ensure a secure fit and prevent you from overtightening the connection and possibly even breaking something.


According to Costa Koulisakis, when a Moon 888’s subassemblies have been finished, the amp is then hand-assembled by a team that then does nothing else until that amp is finished. He told me that it takes about a week to assemble one 888.

Simaudio sent me a white paper explaining the origins of the Moon 888. Evidently the model had been “brewing” in the engineering quarters for at least a decade, but “reality” and “marketing pressures” dictated that Simaudio first develop more affordable products. Over the past three years, however, Simaudio claims it has seen products “emerge in the marketplace with exorbitant price tags,” many from unknown “start-ups” whose futures are equally unknown. Meanwhile, throughout the past decade, all of the costliest and “tweaky-ist” sound-improving ideas Simaudio has been unable to implement in its more affordable products were thrown into what it calls its “skunkworks closet,” in the hope that someday that closet could be emptied and the ideas therein put to good use.

Ultimately, while many if not most of the skunkworks ideas went into the design of the Moon 888, Simaudio chose a generally conservative route, including eschewing a new look in favor of something that would better match the company’s other products. Rather than use a new and “revolutionary” circuit design, the company stuck with its proven amplifier technology, but greatly augmented it with reference-quality, no-expense-spared parts.

Their idea seems to be: If you like the Moon 330A stereo power amp, you’ll probably love the stereo Moon 860A—and if you love that, you’ll really love the Moon 880M monoblock. And if you really love that, more likely than not you’ll want to toss the Moon 888 in your bed and sleep with it before installing it (footnote 1).


Simaudio admits that the Moon 888’s model number—and, I guess, its price per pair of $118,888—is pure marketing: In Asia, the number 8 represents good fortune. In fact, the amp can supposedly output 888W RMS into 8 ohms. The 888’s core circuit technology is taken directly from Simaudio’s Moon 880M monoblock, which sells for $45,000/pair, but with “cost is no object” parts and implementation. Circuit features include zero global feedback, and only local feedback stages. Simaudio claims that they’ve been continuously refining their use of zero global feedback since 1986. They say it results in superbly stable amplifiers and, perhaps of equal or more importance, when properly implemented it offers superior phase characteristics and top-end clarity, which in turn result in bigger soundstages with more ambience, and more air around instruments and voices.

Another of the Moon 888’s novel features, also from the skunkworks closet, is referred to by Simaudio as a “harmonized electro-mechanical output”: The cast-aluminum heatsink is designed so that the output section is fully inset within it rather than being bolted on to the heatsink’s outer surface. This results in the most efficient conduction of heat, aided by a large thermal pad between the output board and heatsink that draws heat away from all circuit-board components. The results, per Simaudio, are lower and more stable operating temperatures, and thus improved linearity and less distortion due to heat, which all adds up to higher sound quality.

Footnote 1: If you think that’s far-fetched, back in the 1960s I knew a guy so in love with his Corvette that, after it was totaled, he slept with its engine. Name and occupation available on request.

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Simaudio Ltd.

US: Simaudio Ltd.

2002 Ridge Road

Champlain, NY 12919

(450) 449-2212


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