Musical Fidelity

M8xi Integrated Amplifier

£6,799 RRP

"Quantity", as someone once said, "has a quality all of its own." And so it is with amplifiers – because there's nothing like a lot of watts to really get a speaker singing. That was the thinking behind Musical Fidelity founder Antony Michaelson's claim that you really needed at least 500W RMS per channel to accurately reproduce recorded music. If memory serves, he happened to be launching a new half-a-kilowatt power amp at the time, but I'm sure that was just a coincidence.

Seriously though, all other things being equal, having a big muscle amp is an unalloyed good thing. Even if you don't listen at exceptionally high volumes, something that packs a serious punch will be far more at ease at normal listening levels and won't be knocked off course by loudspeakers that present difficult, reactive loads. All of this becomes clear after some quality time spent with the 550W per channel Musical Fidelity M8xi that you see here.

The company is, of course, now run by Heinz Lichtenegger, who bought it from Antony several years ago. Yet the ethos – and indeed many of the original team – live(s) on. Alongside his fascination with smallish, affordable Class A amps, he did a serious line of massive muscle amps – many of which were aimed at the big Mark Levinson, Pass Labs or Krell-type designs of this world, where big is beautiful. The M8xi fits the bill, yet it's significantly less expensive than the aforementioned products. Costing £6,799, you'd never call it cheap – but what other design on sale gives so much Class AB power for the money?

My concern with high-powered amplifiers is that they often tend to sound different – rather than better – than high-achieving, lower-powered designs. Obviously, the more watts you're pushing out, the bigger the power output devices need to be, and/or you need more of them. You also need beefier power supplies, complete with larger power transformers with more windings, and then there's the expensive heatsinking that you need to pay for. The point is that small, simple circuits can often offer greater musical enjoyment than vastly more complex ones. It's a similar effect with cars; tune up the engine, and you need bigger wheels, tyres and brakes, plus beefier suspension, to cope with the extra power. Suddenly, you've got a more unwieldy machine.

The challenge for the M8xi, then, is whether it can follow in the sometimes illustrious footsteps of the company's previous super-amps, such as 1990's A1000 or the NuVista M3, Tri Vista 300, kW500, M6/500i and NuVista 800 that followed? Put simply, can it justly claim premium status on the monster integrated amplifier scene?

UP CLOSE

The M8xi is essentially a preamplifier and two monobloc power amps in one big box. Each of the three sections gets its own power transformer, and each is located in an optimal way – for example, the preamp is close to the input sockets, which makes for short printed circuit board tracks. In fairness, this is not exactly novel, but it's still the right topology for a giant integrated such as this. The power amps each sport twelve bipolar power transistors, rather than MOSFET power modules, which are more widely used. This is an interesting choice, as the debate between which of the two approaches continues. A claimed 200 amps peak-to-peak is said to be available.

Musical Fidelity states that the output stage efficiency has been increased on this latest version of the amplifier and claims it gives about ten percent more power for a similar supply voltage. The power amp design has gone for low negative feedback; higher amounts will improve measured distortion figures but are widely thought to be sonically deleterious. The driver stage is pure Class A, too. The result is a claimed power output figure of 550W per side into 8 ohms and 870W into 4, with a peak 1.6kW into 2 ohms. Distortion is said to be lower than 0.005% in the audible frequency range of 20Hz to 20kHz, which is a very good figure for those who pay attention to such things.

As you'd expect, a giant integrated amplifier needs to have a properly large volume control to declare its intentions to the world, and the M8xi sports precisely this. Behind the large silver aluminium knob is a smooth-acting, high-precision potentiometer with laser-trimmed substrate resistors. Another large control takes care of source selection in conjunction with the large-ish, centrally-mounted display. This lets the user scroll through two pairs of unbalanced RCA and balanced XLR line inputs, as well as the various DAC inputs. Two coaxial (S/PDIF) and two optical (S/PDIF) digital ins are offered, along with one asynchronous USB Type-B. A Texas Instruments PCM5242 DAC has been fitted, complete with its own power supply. The coax and USB inputs work up to 24-bit/192kHz resolution, and the optical input goes up to the usual 24/96. Musical Fidelity says the incoming digital data is upsampled and reclocked to reduce jitter.

As with most Musical Fidelity products of the modern era, the M8xi is made to a very high standard in Taiwan. The front fascia panel is a classy aluminium extrusion, and the accompanying metal casework is also well-finished; the custom-made heatsinks give a rugged appearance but are certainly not just for show. Measuring 485x185x510mm [HxWxD] and weighing 46kg, this is no shrinking violet – you'll need a large and sturdy support. My only gripe is the plasticky remote control, which feels pretty low rent. The company could surely do better for not much more expense – either that or it could offer a lovely aluminium one for a little more money.

The built-in DAC proved to be a perfectly nice-sounding design, but it was simply not of the same calibre as the Chord Electronics Hugo TT2 that I used for this review. I got the best sound from the latter when feeding the M8xi's balanced inputs. I used a range of loudspeakers, from modern NEAT Majistras to my classic Yamaha NS-1000Ms.

SOUND QUALITY

The M8xi sounds more subtle than it looks. You'd expect it to be an absolute fire-breathing monster, a destroyer of loudspeakers, a shaker of rooms and the scourge of your listening room plastering. Of course, it can do all of this, but only if you pump up the volume really aggressively. At most listening levels, it gives a smooth, confident, authoritative sound that is totally unfazed by whatever speaker it is driving, but it's not in the least bit hard or harsh. Indeed, it has a pretty subtle and neutral character, with well-controlled bass, a smooth treble and a midband that's detailed but not too forensic. It's certainly not a 'character amplifier' in the manner of a classic Naim NAP250 power amp, for example, or even a modern Krell KS-300i integrated.

Feed it with a well-recorded contemporary pop track like Public Service Broadcasting's Go!, and the sound you get is spacious and absorbing. It's clean, clear and open without being in your face; it doesn't try to etch the treble on your cranium despite the track's powerful rock drumming and biting hi-hat cymbal work. The bass line is firm and insistent, yet there's no sense of bloat – instead, you get strong low frequencies that are remarkably uncompressed yet carefully controlled. Indeed, compared to some less expensive integrateds, such as Exposure's excellent 3510, it actually sounds more bass-light in many situations, as there's less overhang and slurring of the bottom end.

This is all good news, then, and there's more. Give this monster amp a typically thin, scratchy-sounding guitar rock track such as The Pretenders' Don't Get Me Wrong, and the sound isn't nasty and analytical. The M8xi emphatically does not spend its time telling you what's wrong with the recording. Instead, it lets the recording's key details flood out – such as the nuances of Chrissy Hynde's jangling guitar work and her lovely, gravelly but fragile vocals. Bass is taut and propulsive, and the drum work sounds assured but not forced. The overall effect is of a high-paced, jaunty pop song that's smooth but never dull.

This big integrated is not the most detailed design I've ever heard – for example, the slightly more expensive Rotel Michi X2 S2 does a wee bit better in absolute transparency. Yet the Musical Fidelity has a less forward and ultimately more inviting sound that's a fraction less impressive but more satisfying to my ears. The early eighties synth-pop of Soft Cell's My Secret Life is one of those recordings that keeps getting better the more the replay equipment improves. There's a little roundness apparent from the M8xi in the way it carries the percussive synth line towards the end of the song; it's ever so slightly soft around the edges. Yet, still, this amplifier is a natural music maker and lets the music flow better than both the aforementioned Class AB Rotel and the equally premium Class D Marantz PM10.

The soundstage is cavernous and really is quite a thing to hear. It treats even large, current-hungry loudspeakers like they're toy dolls and plays with them with absolutely no fear; my Yamaha NS-1000Ms simply dissolve into the recorded acoustic and do what they're told. The classic prog rock of Steve Hackett's Star of Sirius is amazing to witness – the listener is pulled right into the recorded acoustic, complete with vocalist Phil Collins' close-miked vocals set in front of a dreamy Mellotron, gently picked electric guitar and noodling ARP synthesiser. It's quite beautiful, and the joy of all that power is that it remains constant even when you're playing at very high levels and/or on loud dynamic peaks.

THE VERDICT

This is a very fine-sounding mega muscle amp that's a positive bargain at its price. Although not cheap, it compares extremely well with its direct market rivals and sounds disproportionately better than many, only slightly less pricey products. Design, build and finish are excellent for the money, too. The worst thing is its size and weight, but all those watts have got to be dissipated somehow. So it's true then – when properly done, Musical Fidelity's M8xi shows that bigger can be better.

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