Moon 760A stereo power amplifier
Pity the audiophile with an amplifier to buy and the asking price of a Moon 760A burning a hole in their pocket. It’s a first-world problem sure enough, and no doubt one that many of us wish we had too. But it’s a tough one because round about that price point our buyer has a good number of contenders in view. Which to choose? Canadian manufacturer Simaudio would like it to be one of its Moon range of amplifiers.
In March 2022 I reviewed the company’s Moon 340i integrated amplifier. It turned out to be something of a bargain for its then RRP of £4,100. One question might be: if we spend more than twice as much, £8,400, on the Moon 760A, do we get twice the sonic value? The Moon 760A is ‘just’ a stereo power amplifier, so unless we have a DAC, streamer or phono stage with a built-in volume control a line stage will be required as well. That significant fact aside, the 760A offers 130 Watts per channel into 8 Ohms and 260W into 4 Ohms, the first five Watts of which are in Class A.
If we regard our amplifier as more than just a black box, and are interested in what’s going on inside, the Moon 760A makes a compelling argument for itself. Unusually – and not just for this strongly contested price band – it is properly dual differential from input to output, setting it aside from alternatives that are pseudo-balanced only. Some vendors claim that going the whole hog as Simaudio has done is an unnecessary complication. Single-ended can be made to work just as well. Sometimes the single-ended/balanced argument can only be resolved by comparative listening tests, and that’s certainly the case with the Moon 760A.
Designed and implemented well, fully dual differential, as we find in the 760A, allows engineers latitude in other areas that intelligently exploited turn out to be highly significant. It has enabled Simaudio’s design team to avoid using global feedback in the gain stages while still achieving competitive noise and distortion figures. Without the same burden of feedback carried by many competitive amplifiers the 760A is able to maintain better phase accuracy and achieve lower intermodulation artefacts (Simaudio claim zero). Add signal paths as short as can be achieved with the circuit design and these outcomes combine to create an intriguing prospect.
The Moon 760A does have single-ended RCA inputs on the rear panel, but using them instead of the adjacent balanced XLR inputs would be rather like buying a Ferrari Roma and driving it around in first gear all the time. I evaluated the Moon amplifier by connecting its XLR sockets to an icOn4 PRO Balanced line stage fed by a Mola Mola Tambaqui DAC.
The amplifier was brand new and Simaudio’s UK distributor Renaissance Audio recommended some 300 hours of running in. In the event the 760A sounded more than agreeable for the first 24 hours of operation and just went on to get better still, without the wide extremes of sonic performance that can characterise the running in of new kit. I ran the 760A for 15 days, powered on all the time, and by the end of the process was rewarded with a distinctly superior high-end listening experience.
Simaudio wants all users – not just reviewers – to leave the 760A running all the time, allowing it, the company says, to achieve its maximum stable sonic performance. The 760A draws 35 Watts on idle. While that’s not insignificant in these times of high energy prices, we might regard it as an acceptable trade for what comes next.
The hot side
The 760A has a non-adjustable gain of 31dB. Fed a 6V balanced signal the review sample sounded considerably more powerful than its output specifications might suggest, indicating that its engineers have teamed the gain stages with a power supply possessing a deep well of energy. Recording-dependent of course, but with all that gain – 31dB is distinctly on the hot side – the 760A needed eight to ten dBs more attenuation (less volume) than my reference amplifier requires.
While we might therefore regard the Moon amplifier as rather pedal-to-the-metal, delivering in-room SPL peaks of 98dB through PMC MB2se speakers it sounded relaxed, refined and in control, with no sense of being anywhere near hitting its straps. At lower volumes it retained a good measure of the satisfying dynamic expression that it generated at higher settings.
It is a transparent amplifier, more so than most of those that I have encountered at the price point and somewhat beyond. And not in a shouty ‘look at me’ way. The tonal balance doesn’t lean towards the upper octaves, but in a refined, full bandwidth, DC coupled way brings a sense of satisfaction; we end listening sessions knowing we have been told the full musical story rather than a highlighted part.
The high phase accuracy claimed by Simaudio proves to be subjectively present, combining with strong dynamic agility to allow the 760A to throw a sound stage that on some recordings becomes quite arresting; tiny details popping out of relative blackness with such confidence that listeners’ eyes flicker around, being drawn to the points in space where they momentarily hang.
Simaudio makes a particular point about the transistors it uses in the voltage gain stage of the 760A, apparently a proprietary design, highly linear, precision-matched and fully decoupled, resulting, says the company, in strong bass response and accurate sonic reproduction. It’s a claim I was unable to test by measurement, but listening sessions supported Simaudio’s claim.
The amplifier is DC coupled and the depth and quality of low-end that it can generate on some material is quite startling, giving Victor Wooten’s bass on Trypnotyx, for example, an uncommon sense of both power and fine-grained texture. These two key qualities extended upwards through the audio band right to the upper limits where my hearing began to check out, making the 760A one of the most expressive and informative amplifiers to grace my kit table in some time.
Detail at the extremities
Tonally, the 760A reminded me of the lush, colour-rich characteristic that the best of tube amplification can achieve in the midband. Don’t read that last sentence as suggesting that the 760A is coloured, as in non-linear. That’s not what I am saying. What it does is exhibit the important competence of tonal accuracy fully top to bottom, digging out tonal detail even at the extremities that many other amplifiers skate over.
There’s an organic warmth and realism to instruments of all types, including that of human voice, that I found particularly satisfying, closer to the real-world tonal qualities to be heard at live acoustic events. I played Clare Teal’s Live At Ebenezer Chapel, and on the track Tea For Two the 760A told me when Teal breaks into a wide smile as she sings; the timbre of her voice changing, becoming warmer as her mouth forms the smile.
Obsessive? Nope. For me, it’s the very kind of micro-detail that helps create the you-are-there illusion and makes quality audio so engaging and satisfying, elevating it, if you will excuse the pun, from a lift-music experience to an immersive, full-on performance. The same track confirmed that the 760A achieves an equally fine degree of timing, with crisply snappy transients when required and on the other hand slow-building events delivered with equal conviction.
Trails at the end of piano notes, for example, were not masked by a high noise floor but left listeners hanging in suspense, ending only when pianist Grant Windsor decided they should end and took his toe off of the sustain pedal. It’s what all amplifiers should do but not that many do as well.
Moon 760A verdict
The Moon 760A is a well-engineered and voiced amplifier that demonstrates highly satisfactory and balanced abilities in all four of the key musical pillars of dynamic expression, dynamic agility, tonality and timing. Class leading for the money? Yes.