Note: for the full suite of measurements from the SoundStage! Audio-Electronics Lab, click this link.

I’ve been a tube guy for much of my life, but I’ve always been acutely aware of the deficiencies of most tube amps—noisy, unreliable, hot, soggy-bottomed, and rolled-off up top. Why on earth would anyone want to listen to and own one of these liabilities? You can likely guess my rationale, right? It’s that magic middle that has always drawn me in. For most of my audiophile life, I’ve been willing to deal with the extensive support infrastructure that, by necessity, has to go along with the ownership of a tube amp—especially the vintage ones that always seem to end up between my speakers—in order to receive that lush midrange that only tubes can produce. Over the years, I’ve purchased a couple of solid-state amplifiers, but I’ve always sold them and gone back to tubes.

Back in 2017, fate played a cruel trick on me when the Simaudio Moon 860A stereo amplifier landed in my room. As you can read in my SoundStage! Ultra review, the Simaudio turned my head around—it truly woke me up to just how good a solid-state amplifier can sound.

The 860A had it all—it was neutron-star dense, built to an insanely high standard, and its power doubled down when the impedance halved, which has always impressed me due to my long history as a high-end car audio enthusiast. Oh, yeah—and it sounded superb, and I could listen to it for hours on end.


It was my experience with the Simaudio that caused me to investigate and purchase the Bryston 4B3 amplifier, which is still a permanent resident in my listening room.

So, four years later, what does Simaudio do? They go and release version two of the amp that was the genesis for my exodus from tubes.

The 860A v2 sits right in the middle of Simaudio’s revised line of 8-series power amplifiers. The amp that used to occupy the spot just above the 860A was the 870A, and above that was the 880M monoblocks. But Simaudio has compressed the product line to include just the 860A v2 and their flagship 888 monoblocks.

These amps, the 860A and the new version two, are still cut from the same cloth. Both amplifiers are fully dual mono from the power cord onwards, and fully balanced from input to output. The amp’s chassis is CNC machined from solid aluminum, and it’s a real looker—my sample was black with silver accents, and the anodized finish was beautifully brushed.

That said, there are significant differences between the original 860A and the new version. So many things have indeed changed that Simaudio says it’s perhaps best to think of the v2 as an all-new amp, one that’s more closely related to the whopping great 888 than the previous 860A.

One of the biggest departures from the original 860A is the new condensed circuit board, which significantly shortens and stabilizes the signal path. Simaudio has also paid closer attention to thermal stability. As Costa Koulisakis, director of Simaudio’s Moon Training Program, explains:

Small signal semiconductors are strategically located on the underside of each channel’s main board and pressed onto the heatsink, which optimizes thermal transfer, in order to achieve a thermal equilibrium that maintains tighter specification tolerances between the two channels. Engineers know that, as operating temperatures diverge between supposedly matched semiconductors, their matching decreases, and sound quality suffers. We have addressed this problem with the 860A v2, and it is the first Moon amplifier (outside the 888) ever to use this design approach.

While the original 860A produced 200Wpc into 8 ohms or 400Wpc into 4 ohms, version two jacks that up a little, to 225Wpc or 450Wpc, respectively. While the power output has gone up by 25W, the power supply capacitance has disproportionately increased. The 860A v2 also has a switch to change it to a monoblock capable of outputting 750W into 8 ohms. It can be run in mono from either its balanced or unbalanced inputs, without the need for an adapter cable.


Another nice-to-have is the choice between AC- or DC-coupled inputs via a switch on the rear of the unit. This feature provides a level of safety for older preamps that might not be as stable. Like my own 25-year-old Sonic Frontiers SFL-2, I guess.

As with progress in general, the price of the 860A v2 has gone up a touch: the original 860A was $15,000, and version two jacks that up a bit to $19,500.


It’s going to be hard for me to adequately impress upon you just how dense this amplifier really is, but here we go. After I’d decanted the amp from its extremely secure double box, I sat there for a while trying to figure out how I could insert it into my audio rack. And inserting it was something I felt I had to do, as I certainly did not want to repeatedly stub my toe on this thing. Anyway, it’s not that much larger than my Bryston 4B3, and dimensionally, it certainly would fit. I pulled the Bryston out by the handy rack handles and set it aside. At 42 pounds, it’s three pounds short of a large weightlifting plate, so it’s not exactly svelte, but I could damn near straight-arm the Bryston out of the rack. The Simaudio, though, doesn’t have those handles, and while the shipping weight is 90 pounds, it feels insanely awkward and dense—more like a solid block of metal than a stereo component. I could just about move the Simaudio by shuffling it around as I squatted immediately over it, but there was no way I could actually pick it up without feeling the discs in my spine squeezing out like warm marshmallow from a s’more. And I’m just these days getting over an L4 pinch, so screw that action.

After laying a large slice of cardboard on the lower shelf, I got the amp’s hind legs up on the shelf and edged it back into place. The 860A v2’s cone feet pierced right through the cardboard and gouged my walnut rack as it slid back, so that spot shall forevermore be dedicated to amps readily able to conceal those battle scars.


So the takeaway here is that this is one dense, overbuilt amp. As a consequence, the Simaudio’s chassis, which consists entirely of milled aluminum, acts as one giant heatsink. No matter how loudly I played music through it, or for how long, the amp never seemed to exceed ambient room temperature.

Operationally, there’s not much to say here. I plugged the amp in and connected inputs and speakers, set the rear toggle switches to balanced inputs and DC coupling—because I like to live dangerously—and then I fired it up. And there the amp sat, switched on, silent, dense, and stoic for the duration of the review period. The 860A v2 gave no indication that it was present in my room, other than to play music whenever required. At no point did it emit any untoward sounds, flash any warning lights, or turn itself off.

What’s a watt anyway?

What’s the toughest test for a muscle amp like the 860A v2? A set of low-impedance ribbon speakers? A large, multi-driver cabinet with inefficient sealed woofers? Go on, you’ll never guess. Well, I’d wager that the most demanding task for such an arc-welder would be pairing it with the Klipsch La Scala speakers that I currently have in for review. Think about this: Klipsch claims that the La Scala is 105dB sensitive—that means if the Simaudio throws 1W into a pair of these speakers, they’ll slam out a jet-engine-level shriek that would immediately damage my hearing. Most of my listening takes place at SPLs in the high 80s to low 90s, so the Simaudio would generally be cruising at an output of about 0.03W. Those huge banks of transistors, that giant transformer, all those capacitors, they’d be doing next to nothing. It’s like a locomotive pulling a Tonka car. However, the Simaudio runs in class A up to the first 5W, so in retrospect, there was hope.

That said, I was actually quite worried about this matchup, as there was considerable overlap in the review periods for these two components, and on the face of it, the combination seemed ridiculous. But it works! And that’s not just it works ok, considering. No, the 860A v2 made sweet, excellent music with the La Scalas. Later in the review period, I swapped in my vintage 16Wpc Eico HF-81 tube integrated, which is, or so you’d imagine, a far better match than the ginormous Simaudio. Well, it sounded different, yes—but better? No. No, it didn’t sound better. The Eico’s tube richness was a nice holiday, but after a week or two, I was quite happy switching back to the component under review.

Case in point—John Zorn’s Alhambra Love Songs (LP, Tzadik TZ 6010) and the peaceful spa bath that is “Mountain View,” which could possibly be the most delicate piece of music I’ve ever heard. With the 860A driving the La Scalas, I felt as if I could reach out and touch the music. The near-constant crash cymbal overlaying the loping piano line was palpable. At no time while listening to this track—heck, to this entire album—did I get any hint of an overtly heavy hand, of a lack of delicacy or subtlety. Quite the contrary. Despite listening to this album repeatedly over the years, it took the combination of the La Scalas and the Simaudio amplifier to reveal to me that it’s actually a three-piece band. This is such deep, intense music that it’s almost beyond comprehension that it’s being played by only bass, piano, and drums.


Back in 2017, I reviewed the 860A—v1 now, I guess—and found myself quietly seduced by its gentle, self-effacing manner. I was expecting a polished stainless-steel sledgehammer, and I sure got the control and bass slam. But the head of that hammer was wrapped in a velvet Crown Royal bag. It was the amp’s ability to gently pluck out the details and nuance in the music that really impressed me.

Far be it for me to try to compare the original 860A to the v2—it’s been four years and much has changed in my system, but I sure as heck remember the overall gestalt that amp imposed on the sound. I spent quite a bit of time listening to the 860A v2 via the La Scalas; I got much the same feeling of space and peace as I recall experiencing during my time with this amp’s predecessor.

That the 860A v2 is a strong solid-state amplifier with excellent control is a given, but as I said earlier, it doesn’t need to do much in the way of the steel-claw thing with the La Scalas. That said, I could easily hear how the Simaudio gripped the overall meter and pace of the music.

Case in point: timing is everything when it comes to King Crimson’s Discipline. This watershed album of my youth changed everything for me. Flash back to 1981 and an 18-year-old Jason standing in line outside the concert venue for the album tour. A man was walking down the line asking each person if they wanted to buy strong acid, and my friend and I, being avid psychonauts at the time, thought nothing of dropping two hits of white blotter LSD 30 minutes before walking into a darkened, tightly packed, general-admission concert hall.

I didn’t know anything much about King Crimson, having listened to In the Court of the Crimson King once or twice, and I was only going to this concert on the recommendation of my friend. The combination of a head full of acid and this fractal, precise, explosive performance utterly changed my world. While I don’t much believe in the old “LSD flashback” myth, I always feel a little hallucinogenic frisson when I listen to the title track. The contrast between the clinical, ultra-precise dueling guitars and the loping, syncopated drum work gets me every time. With the Simaudio fronting the La Scalas, I was right back there—I could feel the amp plucking out the details, separating each instrument into its own section of the auditory world in front of me. My original Canadian pressing of Discipline (LP, Editions EG BSK 3629) is extremely poor, and I suspect the original recording itself isn’t that great, as the digital version isn’t anything to write home about either, but the Simaudio’s natural, unforced presentation, combined with the Klipsch’s unlimited dynamics, pulled me past the low quality of the source material. It might sound like a small thing, but there’s a tiny little ride cymbal off to the side of the soundstage, and the 860A v2 placed it with such crispness and delicacy, it completely captured my attention.


Timing. In that Crimson concert so long ago, I felt I could see the time signature changes; I could taste the way Fripp and Belew slid their dueling guitars out of time and then sucked them back into sync. Listening to it today, via the Simaudio, I got an extra dose of the sensation of two actual guitars, of the two musicians, working more like neuroscientists as they wove an auditory tapestry. Each note sounded as it should, as if it were being produced by a machine—not a synthesizer—without a trace of fingers on strings. The 860A v2 articulated the leading edge of each note, rendering it wonderfully in space, but without resorting to abrasive trickery. This was detail without glare or grit.

A powerful solid-state amplifier coupled with a hyper-efficient tweeter sounds like a poor match, but how wrong you’d be to think that. Since I was rocking out with the La Scalas, it seemed appropriate to toss The Wall (LP, CBS/Sony 40AP 1750-1) onto the VPI. “Young Lust” is a barnburner track, and Gilmour’s searing Strat solo is Dutch-master genius. I could easily hear the 860A v2 take control of that 1″ compression driver and give it depth, bite, and presence. But no grain, you hear me? There were no crunchy artifacts I could lay at the feet of the Simaudio, just clear, crisp, juicy volume and lots of it.

It’s important that you realize my listening time with the 860A v2 was split between the La Scalas and my own, much more conventional Aurelia Cerica XLs. My observations were generally consistent between the two speakers, even though my reactions came from vastly different viewpoints. In second-guessing my review methodology, I came to the realization that the 860A v2 and La Scala matchup wasn’t likely to see the light of day in any other system in the world but mine at that very moment. It really doesn’t make sense, combining this amp with this speaker, despite how incredibly well it worked.

But the Aurelias? They’re a nice, conventional 89dB, 8-ohm pair of speakers that pretty much anyone can relate to. And with the Simaudio fronting the Aurelias, I got a creamy, smooth presentation that had much in common with the La Scala pairing.

Creamy and smooth. The Simaudio amp projected a sense of almost infinite authority. It’s in charge, and its sense of tightly coiled power allows it to present a musical event with an ease, a refinement, that consistently made my shoulders drop and my chest relax with a sigh of release as stress fled my body.

Through the Aurelias, I was better able to gauge the 860A v2’s bass. As you’ll read in the upcoming review, the La Scalas don’t really do bass below 50Hz, so I haven’t said much about the Simaudio’s low end up to this point in the review. The Aurelias though—and this is counter-intuitive given the much smaller boxes—dig down at least 20Hz lower, so we’re in business.


I’ve mentioned the bass virtuosity of Percy Jones a number of times in SoundStage! reviews. Three albums with Jones onboard hold special places in my musical heart: Brian Eno’s Another Green World and Before and After Science, and especially Brand X’s Moroccan Roll. On all three of these albums, you can hear Jones noodling away, grumbling to himself, as it were, playing lead bass at the same time he’s holding down a cracking rhythm line. Jones plays a fretless bass, evincing a level of activity that could be considered manic, packing a shitload of notes into each bar. Delving into Moroccan Roll (LP, Charisma 921-1126), you can hear just how brilliant Jones can be by listening to “Malaga Virgen.” Everything's here—deep, deep bass, rich harmonics, trilling, and blinding runs. And through it all, a lyrical, playful feeling of rich, delicious fun.

Listening to this one track told me volumes about the 860A v2. First, and most obviously, I shouldn’t have to tell you that the Simaudio amp utterly controlled the Aurelias’ woofers. This is a big, strong solid-state amp, and it would be news if it didn’t have tight, controlled bass. The 860A v2 doesn’t inject its own character into the lower registers. You can hear that clarity, that control, as a result of Jones’s continued reliance on the open E—deep and crisp, with sharp edges and an openness to that muted, fretless tone, to the overtones, to the feeling of fingers on strings.

The 860A v2 is a space monster. In “Gravity’s Angel,” from Laurie Anderson’s Mister Heartbreak (LP, Warner Bros. 25077-1), I could hear deep into the mix. The Simaudio would pull details out of this obviously artificial soundscape and render them clearly, without noise or other distractions. Image placement—like the rich, metallic, stringy overtones of Bill Laswell’s bass—was perfectly executed and realistically sized. More than that, there’s a sense of peace, combined with a latent power in the Simaudio’s portrayal of space. This, to me, feels like it’s borne of control, but not of the heavy-handed, constipated type. Rather, the soundstaging of the 860A v2 felt like it came from that rare combination of finesse and almost limitless current.

Big versus bigger

In my back pocket for this review, I’ve been quietly comparing the Simaudio to my own Bryston 4B3 amplifier. Which, I’d like to make clear, I really, really like and with which I remain very content. At its current retail price of $6795, the 4B3 isn’t far from being one third the price of the Simaudio, and I’d have to say that the Bryston is a raging bargain. Still, there’s no question in my mind that the Simaudio is the better-sounding amp. These two solid-state amps are cut from the same cloth—they’re both unbelievably neutral, with powerful bass and a totally grit- and edge-free presentation. I could happily listen to either amp. And given my cost-constrained circumstances, I will continue to happily listen to the Bryston.

But if my seven numbers ever came up on that lottery ticket I never buy, there’s no question in my mind that I’d give the 4B3 to my brother-in-law and pick up a Simaudio or two. Why? Well, it’s undoubtedly a matter of degree. Where the Bryston provides a quiet, clear background, the Simaudio ups the ante by a hair, adding just a touch more depth to the soundstage. The Simaudio is just a touch more restrained in the highs, nipping just a leetle bit off the top of cymbals and sibilants, which is more to my own personal taste.

The main difference between these two amplifiers is more of an overall presentation thing. For an extra $13k or so, you get a more sophisticated-sounding amplifier, one that can more realistically rebuild the original recording space in your very own listening room.

It didn’t take long for me to determine that—yes—the 860A v2 is the better-sounding amplifier. Rather, it took me a long time to figure out why and to distill my thoughts in a coherent manner. And that’s really as it should be—throwing more money at a problem can only go so far in audio, and when you get to these extremely high-end products, improvement is no small feat.

Jason is sad

Simaudio has done it, though. With the 860A v2, they’ve made an amp that’s notably better than my own Bryston, which is already really, really good. The 860A v2 is a true statement product. Without even listening to the thing, it’s easy to see that this amp exudes quality and workmanship.

Really—there’s nothing about the 860A v2 that I didn’t like. Searching back over my time with this amp, I honestly can’t think of any areas for improvement, in either sound quality, build, or functionality. That is truly rare for me, as I can usually muster some sort of quibble, something I’d like to change. But that’s not the case here.


And it saddens me, as, at my current 58 years of age, I’m now starting to take note of and resign myself to the things in this life that I’ll likely never be able to afford. My circumstances are now such that my financial picture is not likely to change much from this point on, and there will be no Ferraris or lakeside mansions in my future. And that means there will not likely be a Simaudio 860A v2 (or two strapped in mono!) coming down the pipe.

Don’t weep for me though—I do have this nice Bryston sitting here, and it’s a great amp. But I just boxed up the 860A v2 and levered it into Doug Schneider’s little SUV. It’s now on its way to Ottawa for measurement—and damn it all to hell—I sure wish it didn’t have to go.

. . . Jason Thorpe

Note: for the full suite of measurements from the SoundStage! Audio-Electronics Lab, click this link.

Associated Equipment

  • Analog sources: VPI Prime Signature turntable; EAT Jo No8, Mobile Fidelity Master Tracker, Roksan Shiraz cartridges.
  • Digital source: Logitech Squeezebox Touch.
  • Phono stages: Aqvox Phono 2 CI, iFi iPhono 3 Black Label, Hegel V10.
  • Preamplifier: Sonic Frontiers SFL-2, Simaudio Moon 740P.
  • Power amplifier: Bryston 4B3
  • Integrated amplifier-DAC: Hegel H120, Eico HF-81.
  • Speakers: Focus Audio FP60 BE, Estelon YB, Aurelia Cerica XL, Klipsch La Scala.
  • Speaker cables: Audience Au24 SX, Nordost Tyr 2.
  • Interconnects: Audience Au24 SX, Furutech Ag-16, Nordost Tyr 2.
  • Power cords: Audience frontRow, Nordost Vishnu.
  • Power conditioner: Quantum QBase QB8 Mk.II.
  • Accessories: Little Fwend tonearm lift, VPI Cyclone record-cleaning machine, Furutech destat III.

Simaudio Moon 860A v2 Stereo Amplifier
Price: $19,500.
Warranty: One year, parts and labor; ten years with product registration.

Simaudio Ltd.
1345 Newton Road
Boucherville, Quebec J4B 5H2
Phone: (450) 449-2212