A couple years ago, Musical Fidelity was bought by Audio Tuning Vertriebs GmbH of Austria, which is owned by Heinz Lichtenegger, a cordial and respected industry veteran who founded and is CEO of Pro-Ject Audio Systems. At the time, a news release stated, “The future vision for Musical Fidelity is to grow with new products and push into new markets, while still retaining the sound quality, reliability and striking industrial design that helped make the brand such an influential part in the annals of hi-fi history.”
ATV, which is primarily Pro-Ject, is best known for designing and manufacturing turntables and, more to the point, the sorts of compact audio components that Musical Fidelity itself has long produced. However, MF has also always made a wide range of other products, including some that many consider ultra-high-end. Musical Fidelity’s first new product since being acquired by ATV is the massively built M8xi dual-mono integrated amplifier-DAC ($6499, all prices USD). Unlike MF’s Nu-Vista integrateds, which use Nuvistor tubes, the M8xi is all solid-state, and is their most powerful integrated to date.
Super in design
I’ve recently reviewed some excellent integrateds near the M8xi’s price, including some big, powerful ones: Anthem’s STR and Cambridge Audio’s Edge A. The M8xi is a bit different. At 19.1″W x 7.3″H x 20.1″D and 101 pounds, the M8xi is a lot bigger and heavier than either of those amps. It’s also a lot more powerful, with specified outputs of 550Wpc into 8 ohms and 870Wpc into 4 ohms. Granted, nowadays there are many big, powerful integrated amps available from a wide range of manufacturers -- but I doubt there are many this powerful or this massive for as little as $6499.
The M8xi is an integrated-DAC that can accept datastreams of up to 24-bit/96kHz at its two TosLink (S/PDIF) inputs, or up to 24/192 through its two RCA (S/PDIF) jacks or its asynchronous USB-B port. It doesn’t support DSD or MQA. Of its four pairs of single-ended (RCA) inputs, Aux 2 can also be used as a home-theater bypass by sliding its little switch to its HT setting, which bypasses the circuitry for the volume control. There are two pairs of balanced (XLR) inputs; two sets of single-ended outputs (RCA), labeled Line (fixed output) and Pre (variable output); a pair of balanced (XLR) outputs; and digital S/PDIF outputs (RCA, TosLink). The two pairs of relatively large, five-way binding posts could have been spaced a bit farther apart to better accommodate bulky speaker cables, considering the sorts of systems this amplifier is likely to be used in. There are also a 12V DC trigger input and output. A detachable IEC power cord is provided, but it uses the C-19 connector more commonly found on 220V/20A cords rather than the more common C-13 connector; something to keep in mind if you want to use an aftermarket cord.
The M8xi’s front panel is relatively empty, and is dominated by two large knobs flanking a small display at center. These knobs boast extremely smooth, luxurious action. At left is the Source selector, at right the Volume knob. The source input selected and the volume level, to the nearest half-dB, are respectively indicated in the right and left sides of the display. Below each knob is a small pushbutton: Power/Stby on the left and, on the right, Display, which cycles through five levels of illumination. Centered below the display is the IR remote receiver, and below that a tiny LED that glows blue when the M8xi is powered up. The faceplate is a slab of half-inch-thick aluminum with a beveled top edge. Large heatsinks comprise the entire surface of each side panel, making the M8xi look the part of a super-powerful integrated -- as if wrestling this big, heavy thing into place in your equipment rack, or even pushing it around on the floor, hadn’t already told you so.
The handheld plastic remote control is serviceable, most of its unbacklit buttons looking somewhat similar and their placement not immediately intuitive. For instance, the small volume up/down buttons are placed side by side and near the center of the remote (instead of Up above Down), each to one side. It didn’t take me long to get used to this, but it’s odd. Helpfully, the buttons for controlling Musical Fidelity source components are gray rather than the blue of the buttons controlling the M8xi. The latter, almost all of which appear toward the bottom of the remote, under Amplifier, include buttons for direct access of each input, and Mute.
Musical Fidelity describes the M8xi as “a separate preamp with two monobloc power amps sharing a common chassis.” The M8xi’s output stage features the latest version of MF’s low-feedback amplifier circuitry, and is more efficient, they say, than in previous designs, providing 10% more power, lower distortion, and higher sound quality. The circuitry includes six Darlington pairs of bipolar transistors per channel, to output a maximum of 67V RMS (20Hz-20kHz), a maximum peak output current of 105A, and a damping factor of 150. The M8xi’s specified total harmonic distortion plus noise is typically <0.004%, 20Hz-20kHz, with a signal/noise ratio of >86dB, A-weighted.
The M8xi’s preamplification stage has its own power supply that’s isolated from the power amps, to prevent leakage of high-frequency noise into the more sensitive preamp circuits. This stage features an IC-based, digitally controlled, analog volume control based on Texas Instruments’ PGA2320 chip. Adjustable in increments of 0.5dB, the PGA2320 uses laser-trimmed substrate resistors, claimed to provide channel and frequency matching of less than 0.1dB even at low volumes.
Digital signals are converted to analog by TI’s PCM5242 DAC chip, whose asynchronous sample-rate converter upsamples all incoming digital signals to 24/192, and reclocks the base input clock frequency to minimize jitter and related noise. MF describes this DAC’s architecture as being arranged in a fully differential analog output topology for the lowest levels of output noise and distortion with a filtered 5V power supply.
I primarily used the Musical Fidelity M8xi with my reference MartinLogan Masterpiece Classic ESL 9 hybrid electrostatic speakers, and a Lenovo IdeaPad laptop computer running Windows 10, Roon, foobar2000, and Qobuz. I also briefly used my reference budget floorstanders, a pair of PSB Alpha T20s. An Oppo Digital UDP-205 4K Ultra HD universal BD player served as a DAC, connected via an AudioQuest JitterBug jitter reducer and Carbon USB link. Accessories comprised my usual assortment of Clarus Aqua speaker cables, balanced interconnects, and power cords, and power-conditioning products from Zero Surge and Blue Circle Audio.
As I have with every integrated amplifier I’ve recently reviewed, I first set up the Musical Fidelity M8xi with my PSB Alpha T20 speakers. However, instead of moving the amp into my family room, as I normally would, I found it easier to move those small floorstanders into the living room -- each speaker is only a third the weight of the M8xi.
I let the M8xi burn in and listened only casually for a few days. The M8xi easily handled the little PSBs, making them sound great. Like other high-quality integrateds that have recently visited my system, the MF made the PSBs sound bigger and more refined than they normally do with amplifiers more commensurate with their modest price of $650/pair. The soundstages on Lady Gaga’s Chromatica (24-bit/48kHz FLAC, Interscope/Qobuz) were very wide and deep. Her duet with Ariana Grande, “Rain on Me,” features a fat, pulsating dance beat that went pretty low and was tight and controlled, no doubt due to the M8xi’s iron-fisted grip on the PSBs’ woofers. Nor were voices lost in the mix even at high volumes, both Gaga’s and Grande’s sounding exceedingly clear and floating free of the speaker cabinets.
But it was when I connected the M8xi to my reference MartinLogan Classic ESL 9 speakers that it became obvious that this integrated was quite unlike any other I’d ever had in my system. Never had I heard that level of control and dynamics from an integrated amp. Several integrateds in the 100-200Wpc range have taken control of my MartinLogans with an authority and a quality of sound that would satisfy most audiophiles, but until now none had provided the effortless sound that I associate with very expensive, high-powered separates. I usually take manufacturers’ published specs with a grain of salt -- but considering the M8xi’s massive build quality and dual-mono design, Musical Fidelity’s spec of 550Wpc into 8 ohms seems reasonable. Chromatica’s soundstages opened up, populated with super-clear aural images of instruments and voices, and deep, solid beats that were still agile and danceable. And when I really cranked the volume, voices didn’t exhibit the compression and slight edginess that every other integrated amp has given them when pushed in my system.
The power of the M8xi seemed almost unlimited. There was no degradation in sound quality at any high volume level I could tolerate. So while I can’t say that the power of the M8xi was limitless, it was effortless in a way that made it a pleasure to listen to, and it was still easy for me to perceive an immense amount of detail in recordings. Elton John’s voice in “Sine from Above,” also on Chromatica, has a slight processed quality that Gaga’s voice doesn’t. Through the M8xi it was easy to hear the slight altering of John’s voice even as the MF reproduced the entire track with excellent clarity and made it unmistakably clear that this was the voice of the legendary rock star. The M8xi was so revealing that it seemed I could hear this layer of processing separately from the voice itself. And while every tiny microdetail of each voice was revealed, the track’s relentless EDM beat filled the rest of the soundstage with equal precision and plenty of power.
Not only did the M8xi reproduce the midrange without coloration, making voices sound especially pure -- the noise floor was also exceptionally low, letting me hear deep into mixes. In “Love Shack,” from the B-52s’ Cosmic Thing: 30th Anniversary Expanded Edition (24/96 FLAC, Rhino/Warner Bros./Qobuz), this ultraquiet background let me differentiate the constant, low-level sounds of partygoers from the infectious beat and the voices of Kate Pierson, Cindy Wilson, and Fred Schneider, and only added to the party-like atmosphere of this lighthearted 1980s track. The fun continued with “Roam (12″ Remix),” the M8xi placing the tight kick drum precisely at the center of the soundstage, the rest of the kit bouncing back and forth between the speakers, and the lead and bass guitars respectively to left and right of center. Each instrument had its own well-defined space, the overall sound being the sort of extremely realistic, three-dimensional soundstage achieved by the best multitrack recordings, and which the M8xi re-created with ease in my listening room.
As might be expected from an amplifier specified to output 550Wpc into 8 ohms, the M8xi could pound out the bass in “Hey Now,” from London Grammar’s If You Wait (24/44.1 FLAC, Columbia/Qobuz), which I played at levels higher than I normally would even with my reference separates. The walls of my room shuddered mightily when the bass kicks in at 1:20, but it was still responsive and well defined. The M8xi did nothing to exaggerate the low frequencies, but merely reproduced them as it should have: low and loud, with good articulation and no boom, even as Hannah Reid’s pristine voice remained always perfectly relaxed, with zero compression or excess sibilance.
While the M8xi could, when required, play louder without strain than any other integrated amplifier I’ve had in my system, it also excelled at revealing all of the delicate aural shading of Lana Del Rey’s Norman Fucking Rockwell! (16/44.1 FLAC, Polydor/Qobuz). This album is a favorite of the SoundStage! Network’s founder and publisher, Doug Schneider, and I’m starting to hear why -- the more I listen, the more its complex juxtaposition of serene musical stylings with biting lyrics grows on me. The lush acoustic production of “Mariners Apartment Complex” sounded gorgeous, and the voices, which alternate between a dry and very intimate sound to something more wispy and ethereal, were always perfectly balanced in the mix. When deep bass does appear, at 1:27, it was reproduced with authority and in perfect balance, without embellishment -- it commanded my attention without distracting me. And when the track ramps down and the delicate yet palpable voices resumed, the transition was smoothly natural. When I played this and other tracks from this album at lower levels, the M8xi was able to maintain the depth and width of soundstage and the balance of voices and instruments. Regardless of the playback level or the recording played, the M8xi always provided absolutely assured, neutral sound, with exceptional linearity from top to bottom.
Loving the sound of the M8xi through its internal DAC, I switched to its balanced inputs, fed by my Oppo Digital UDP-205 BD player, to hear how it would compare. While the UDP-205 is a very good digital source, its sound was slightly veiled in comparison to the M8xi’s DAC fed directly through its USB input. The sound of raindrops at the beginning of Lady Gaga’s “Sine from Above” was similarly clear and realistic through both DACs, but her voice and the bass beat were a bit softer and less focused through the Oppo. The thin layer of electronic processing of Elton John’s voice was less audible, making his voice and that effect more homogenous, more as if his voice were poorly mixed and less like a deliberate choice by the producer. The kick drum in “Thunderstruck,” from AC/DC’s The Razors Edge (24/96 FLAC, Columbia/Qobuz), had less slam and definition through the Oppo -- the M8xi was better able to reproduce these qualities, and to provide a sharper picture of the slashing riffs of lead guitarist Angus Young.
At $4990, Naim Audio’s Supernait 3 costs $1509 less than the M8xi, lacks an internal DAC, and has a much lower specified power output (80Wpc). Nonetheless, the Naim held its own against the Musical Fidelity. When I used the Naim through the Oppo UDP-205’s DAC for AC/DC’s “Thunderstruck,” the soundstage shrank a bit and the kick drum was a little looser, albeit more fulsome, than through the M8xi, but I never felt the Naim lacked power. Young’s guitar wasn’t placed as precisely just to the inside of the right speaker; the hi-hat was now not immediately to its left, and had lost a smidgen of its realistic hiss. The Naim added some weight and body in the midrange, which gave voices (e.g., Lana Del Rey’s) a richness that was immensely satisfying, if not quite as neutral as through the M8xi. And while the Naim lacks a digital input, it has two things the M8xi doesn’t: a sweet-sounding headphone amplifier and a very capable moving-magnet phono stage.
In my review of the Naim Supernait 3, I mentioned how well it placed aural images in sharp relief. It did that, but the M8xi sculpted those same images in 3D with a precision on a par with that of my reference Anthem STR preamplifier ($3999) and M1 monoblocks ($7500/pair). The Naim’s imaging was impressive, but its outlining of aural images and thus their positions on the soundstage were slightly less clearly defined. In this regard, the M8xi was the equal of my Anthems. Whether using its own DAC or that of the Oppo UDP-205, the M8xi had a transparent, truly balanced sound, and enough power to drive my MartinLogan Masterpiece Classic ESL 9 hybrid electrostats to any volume level without distortion -- something I can say of no other integrated amplifier I’ve had in my system. There was never a time I wished for more power than the M8xi could provide, even in comparison to my 1000W Anthem M1s.
While the M8xi was similar to the Anthems in subjective power output and imaging, there were differences in their sound qualities. I think Jason Thorpe best described the sound of the Anthem M1s in August 2013, in his review of Monitor Audio’s Platinum PL200 loudspeakers: “They’re clean and pure, with a delicate, very slightly rich midrange. . . .” That slight warmth in the M1’s midrange added some body to voices, making Del Rey’s even more mesmerizing, and still letting me differentiate the thin layer of processing from Elton John’s actual voice in “Sine from Above.”
Musical Fidelity says that an amplifier should be completely neutral, like a “straight wire with gain.” I’m not sure they’ve entirely achieved this with the M8xi, but they’ve come close.
Meeting the future vision
In the last few years I’ve had several integrated amplifiers around $5000 in my system. I’ve enjoyed my times with all of them, each for different reasons. They ranged from all-analog designs such as the Naim Supernait 3 ($4990) to complex, cutting-edge integrateds incorporating DSP for room correction and bass management: Lyngdorf’s TDAI-3400 ($7199) and Anthem’s STR ($4499).
Musical Fidelity’s M8xi is a relatively straightforward class-AB integrated that includes a built-in DAC. It costs a bit more than two of those other integrateds, but it’s by far the most powerful, with build quality to match. It has little sonic signature of its own, instead, providing a clear window into recordings and hardly ever deviating from absolute neutrality. The M8xi would be perfect for those who value transparency and need an integrated amplifier than can drive to very high levels speakers that would otherwise require powerful separates. If this is the kind of sound you’re looking for, you’d be hard-pressed to do better for $6499, whether for separates or an integrated-DAC. Time will tell which path Musical Fidelity will follow under ATV’s management, but the M8xi continues their 30 years of making powerful, high-performance integrated amplifiers. It seems a step in the right direction.
. . . Roger Kanno
- Speakers -- MartinLogan Masterpiece Classic ESL 9, PSB Alpha T20
- Preamplifier -- Anthem STR
- Amplifiers -- Anthem M1 monoblocks
- Integrated amplifier -- Naim Supernait 3
- Digital sources -- Lenovo IdeaPad computer running Windows 10, foobar2000, Roon, Qobuz; AudioQuest JitterBug jitter reducer, Oppo Digital UDP-205 4K Ultra HD universal BD player
- USB link -- AudioQuest Carbon
- Speaker cables -- Clarus Aqua Mk.II
- Interconnects -- Clarus Aqua Mk.II
- Power cords -- Clarus Aqua
- Power conditioners -- Blue Circle Audio PLC Thingee FX-2 with X0e low-frequency filter module, Zero Surge 1MOD15WI
Musical Fidelity M8xi Integrated Amplifier-DAC
Price: $6499 USD.
Warranty: Seven years, M8xi; one year, remote control.
A Division of Audio Tuning Vertriebs GmbH
Phone: +43 1-544-858-0400