Up to 37% in savings when you subscribe to hi-fi+

Begin typing your search above and press return to search. Press Esc to cancel.

Simaudio MOON 860A v2 Power Amplifier

Simaudio MOON 860A v2 Power Amplifier

Some products and some companies are just noisy – literally, metaphorically or euphemistically. Others are calmer, quieter and altogether more understated. For the last couple of decades, Simaudio has been consistently responsible for some of the best value, best performing and most reliable (semi-)affordable amplification on the market. From super-musical integrateds to the pocket-battleship 400M mono-blocs, these have been go-to products for review and recommendation, demonstration and daily deployment. Nor is the company any stranger to technological innovation or innovative concepts; the excellent MiND network replay solution continues to win. MOON has been evolving and improving its products, working its way up-market, ever closer to state of the art.

Whilst the midrange MOON electronics have a stellar reputation for no-nonsense performance, and excellent value, their more serious, high-end offerings are all too often, unfairly overlooked when the very best get discussed. But if that’s as wrong as it is irrelevant to most of us, it’s an almost heinous oversight when it comes to the next rung down, the sort of high-end products that we might be able to afford – products precisely like the 860A v2 reviewed here.

The first indication of the company’s elevated ambitions arrived in the shape of the superb 850P line-stage, followed a few years later by the imposing 888 mono-bloc power amps, products to stand comparison with any on the market. But even though these flagship designs maintained MOON’s reputation for value (at least compared to the immediate competition), they were still way beyond the means of most mere mortals. Which is exactly where he 860A v2 comes in, an amplifier on a mission: one model that replaces no fewer than three in the previous range (the original 860A, the 870A and in bridged mode, the 880M) it promises to not only surpass the performance of all of them but do so at something approaching a reasonable price. The latest v2 incarnation of the 860A (£16,750) remains true to MOON’s heritage, being a totally dual-mono, fully-differential, zero global feedback design – down to the separate power transformers for each channel. As such it has both evolved from its predecessor and benefitted from trickle-down technology derived from the 888 flagship. The result is more power, twice the reservoir capacitance, a wider signal-to-noise ratio, lower distortion and improved usability/upgradability – that latter quality reflected in the rear-panel switches that allow users to select between stereo and bridged mono operation and AC or DC coupled connection (to match different system and pre-amp requirements – something many an owner of an ARC pre and Krell power combination could have benefitted from). In a world where audio electronics are becoming increasingly smart, perhaps best typified by the multi-mode (but far more expensive) CH Precision amplifiers, this MOON isn’t just beefy, it’s clever too. And before you start carping about nearly £17K being described as “almost affordable” take a look at the current price on the similarly powered but significantly less versatile Naim NAP500…

Wanting to investigate the inherent upgradability built into the 860A v2, I obtained two units for the review, a decision that opened up not just mono but also bi-amped operation. Combine that with the paper power output – and MOON amps have a reputation for making a nonsense of their rated outputs – and (once again, on paper) you open up an almost unlimited range of partnering speaker options. Most modern speakers might have eschewed the crippling loads and insensitivity so common a decade or so ago, but that doesn’t mean that they don’t like power! However, in this case it’s not as simple as one size fits all and there’s more to power than just the numbers. As MOON amps past have so ably demonstrated, there’s power, and then there’s the nature of that power and, in the case of the 860A v2, that nature is pretty darned specific. MOON amps – all MOON amps – have always sounded bigger and more powerful than you expect: unburstable, unstoppable and utterly unflappable, they’ve made a point of taking pretty much anything in their stride. They’ve also been warm, weighty and fluid in character, eschewing the etched and spot-lit, ultra-defined and almost mechanical sound of so many competing products. The 860A v2 is definitely an archetypical MOON amp!


Audio reductionists will happily give the credit for this to Simaudio’s use of large, linear (as opposed to switch-mode) power supplies, but there is and always has been more to it than that. MOON makes products for the long haul; products that take time to hit their stride, but once they do, deliver music that’s engaging and entertaining – and do it long-term. They may not impress in a quick, starting from cold comparison, but given the chance, they’ll impress first with the music they deliver and later with their reliability and longevity. That makes for a range of highly recommendable products, but whilst their warm and slightly rounded character makes them ideal for long-term listening, it also means that you need to choose matching speakers with care. Warm and weighty can quickly become less than nimble in the wrong system, at which point you might as well spell fluid with a T, a U, an R, G, I and D.

So let’s start with what you shouldn’t use… First and foremost, you want to stop the amp’s attributes becoming weaknesses – and that means preventing its smoothly fluid weight becoming lazy. You do not want to use this amp with speakers that need a wake-up call or a boot up their reflex ports, the studied neutrality and understated dynamics of the Wilson Benesch Resolutions being a case in point. Likewise, although the Wilson Sasha DAWs enjoy the scale that comes with hooking up the 860A(s), their easy breathing, expressive sense of rhythm and dynamics leave the combination sounding like the speaker is waiting for the amp. But fear not, while these are both exceptional speakers, they’re also exceptions to the rule, with candidates that do require just precisely what the MOON amps offer queuing around the audio block. Front of the line you’ll find floor-standing speakers from Magico, YG Acoustics and B&W, with the KEF Blades, multiple PMCs and current Sonus Fabers crowding in behind – a selection that embraces an awful lot of real-world systems…

As if to underline that point, I got to play the 860A v2 with a wider than usual range of speakers, the Spendor D9, Raidho TD-1.2, Vienna Acoustics Liszt and Gershman Grande Avante Garde proving particularly successful. But one thing that did emerge across all that listening was the 860A v2s clear preference for plenty of cross-sectional area in the partnering speaker cables. Whether Crystal, Nordost or AudioQuest, moving up a model/size in terms of speaker wire always produced a disproportionate improvement. Show the 860’s output stage a cable with plenty of metal, and it’s going to respond with all the gusto you’d expect – and then some.

Amongst the partnering speakers, I found myself returning to the Gershman and Raidho models more often than not. Of course, one advantage of pairing the MOON amps with their fellow Canadians was that the Grande Avante Gardes allowed me to ring the changes, stereo to mono to bi-amp – with interesting and for me at least, slightly unexpected results. Running a single 860A in stereo mode was more than capable of driving the wide-bandwidth and moderate efficiency of the Gershmans, producing a sound that put presence and an almost irresistible musical momentum ahead of clarity, definition and articulation. There’s no denying the appeal of that unstoppable forward motion, but when it comes to tracks like The Pixies’ ‘Here Comes Your Man’, the music pushes through the verse and chorus, the middle-eight and the arrangement as a whole with such drive that some of the complexity and layering in the mix gets smoothed over or steamrollered en route. The chopped bass line that underpins the chorus gets rounded off, the harmonies that shade the lead vocal are harder to pick.

In contrast, the jaunty clarity and upbeat rhythms of Vampire Weekend’s Father Of The Bride become so infectious they seem almost turbocharged. Suppose transparency and insight are lower down the MOON’s list of performance priorities. In that case, entertainment certainly isn’t and, if that judgement of its character seems harsh, it perhaps reflects a prolonged period spent enjoying the unforced clarity of (rather more expensive) amps from CH Precision and my own VTL S400 II. Which makes what happened next all the more intriguing…

Adding a second 860A v2 to the mix doubles the price, but doubles the options too – and for once I was surprised to discover a clear preference for the bridged mono set up over the bi-amped arrangement. Yes, vertical bi-amping (using the two halves of a single amp to drive the upper and lower ranges on a single speaker) brought serious benefits in terms of timing, space, focussed energy and a more natural, unforced musical progression, but it couldn’t match the clarity, separation and definition that came with the switch to mono. Running the amps bridged restored the blunt notes in the Pixies bass line, just as it revealed the angular energy and physical effort in Marco Ceccato’s bowing, the familiar vivacity in Gli Incogniti’s accompaniment of the Haydn Cello Concerto VIIb. In contrast, the bi-amped arrangement smoothed the cellist’s playing to an almost violin-like quality that robbed the performance of its captivating vitality.

As a long-time fan of bi-amping (and sometime cynic when it comes to bridging), I was surprised, to say the least. But the results were consistent across all genres – if less so across different speakers. A brief trial with Living Voice Auditorium R25s (a less than ideal match but one that left the mono amps sounding heavy and leaden) confirmed that results are going to be speaker-dependent, but that’s really the point. These amps don’t just let you choose – they let you change your speakers or just change your mind, the kind of circumstantial shifts that all too often come with serious price-tags attached. Just be aware that it’s not a simple either/or comparison. You will need to adjust the placement of your speakers for each amplification option; such is their impact on low-frequency extension and presentation.


But the 860A v2s turned their most impressive trick with the diminutive Raidho TD-1.2s. Big amps and little speakers is an old story in audio circles, but this was the most successful pairing I’ve enjoyed since the ARC M300s fell in with the Electa Amators! The MOON’s weight, presence colour and scale seemed to graft effortlessly onto the Raidho’s dynamic discrimination and rhythmic articulation, the speaker’s subtlety and resolution delivering just the structural skeleton that the amps’ meat and two veg demand. Playing the recent Orfeo Sibelius Violin Concerto, where the stereo amp tended to highlight Baiba Skride’s more dramatic and flamboyant aspects, the mono amps brought forth not just her virtuosity but the soul and depth in the playing, the scale of the acoustic and the power at the bottom end in the orchestral climaxes, a natural extension of rather than extruded from the speakers. This was an object lesson in just how much you can coax from a small set of speakers – if you give them the right encouragement.

MOON’s 860A v2 is an exciting and versatile beast, but it also stands apart. On the one hand, it cannot match – even in mono mode – the unforced clarity and lucid communication of an amp like CH Precision’s M1.1. On the other, it doesn’t cost nearly as much. What it does offer is the sort of sheer presence, musical momentum and colour that has become increasingly rare amongst the current generation of solid-state amps – and which works spectacularly well with many of today’s loudspeakers. It might (sensibly) sacrifice ultimate transparency and resolution on the alter of the musical whole, but in one sense it stands astride, with one musical foot in the past and the other equally firmly in the versatile, adaptable future. If the majority of remotely affordable, silicon-based designs have got too clean, too tight and too up themselves, this MOON quietly offers a welcome antidote. The fact that it’s practical, reliable and versatile too is a generous layer of icing on what is, by any measure, a pretty tasty and seriously substantial cake.


  • Type: Dual mono, user bridgeable, solid-state amplifier
  • Inputs: 1 pr single-ended RCA
    1 pr balanced XLR
  • Outputs: 1 pr 5-way binding posts/channel
  • DC Coupling: User switchable
  • Rated Output: 225W/Ch (8 Ohms); 450W/Ch (4 Ohms); 750W/Ch (8 Ohms bridged)
  • Input Sensitivity: 1.2V
  • Input Impedance: 47.5kOhms
  • S/N Ratio: 110dB/full power output
  • Gain: 31dB
  • Dimensions (W×H×D): 476 × 192 × 445mm
  • Shipping Weight: 40kg
  • Finishes: Black, Silver, Black/Silver
  • Price: £16,750

Manufacturer: simaudio.com

UK Distributor: Renaissance Audio
Edinburgh, Scotland

Tel: +44 (0) 131 555 3922

URL: renaissanceaudio.co.uk 



Read Next From Review

See all
dCS APEX digital converter upgrades

dCS APEX digital converter upgrades

The Ring DAC is core to dCS's exemplary digital performance and has remained at the pinnacle of converter design for the last 30 years. But the new APEX upgrade raises its performance still further, according to Chris Thomas.

Shunyata Research Everest 8000

Shunyata Research Everest 8000

Alan Sircom discovers the joys of isolation (at least between components in a good audio system) thanks to the Shunyata Research Everest 8000 power distributor.

Revival Audio Atalante 3

Revival Audio Atalante 3: Dynamic, crisp, detailed

hi-fi+ Editor Alan Sircom reviews the Revival Audio Atalante 3.

Sennheiser IE600

Sennheiser IE600

The wired in-ear monitor is a rare beast in today's audio world, but that doesn't mean it shouldn't be taken very seriously. Simon Lucas tries the latest in high-end wired universal-fit in-ear monitors from Sennheiser, the IE600.

Sign Up To Our Newsletter