In July 2025, I published on Hificlube: ‘Musical Fidelity B1 xi – The Spirit of the Times’. A year later, I am hands-on with the m6xi—a beefed-up version of the B1xi, with 5 times the power and 5 times the price.
The 'xi' version (€3,300) uses the same analogue platform as the m6si, adding digital functionality to meet contemporary demands — much like the B1xi, which I once described as an 'adrenaline shot'. Now imagine the adrenaline of an integrated amplifier with the same DNA but five times the power.
But let's take it step by step.
The Musical Fidelity m6xi—yes, with a lowercase ‘m’—belongs to the old British school of the legendary Antony Michaelson: a virtuoso clarinettist and committed audiophile. His philosophy of attacking music with energy was adopted by Heinz Niggerlicht of the Audio Tuning Group (Pro-Ject), the current owner of Musical Fidelity.
Heir to the Titan
Those who favour a powerful sound need an amplifier with current delivery, control, stability, a silent noise floor, and dynamic headroom: qualities Michaelson always strived for in his flagship models, such as the Titans. This remains the guiding principle of the m6xi where ‘x’ is no longer an unknown; it’s a certainty
It retains the m6si analogue heritage whilst adding digital connectivity for a more contemporary integration — without ever ceasing to be a true analogue amplifier, rather than merely a box of software with speaker terminals. There are no illuminated displays or touchscreens, no decorative flourishes that might place it in the 'luxury lifestyle' category—save for the small blue LEDs.
There is no headphone output either. Just two rows of small press buttons labelled with their respective inputs, flanking the large rotary volume knob, all finished in grey against the matt-black fascia. Note: an all-grey or all-silver version is also available.
The aluminium chassis with front, sides (heatsinks), and top panels machined from extruded aluminium profiles has a genuine physical presence and weight (16 kg) yet retains an understated quality that keeps it from looking merely industrial. Civilised strength has always been the hallmark of this brand.
The volume knob activates a Burr-Brown attenuator that regulates the analogue signal via digitally controlled resistors for better channel balance without compromising signal quality.
The m6xi logo is engraved on a discreet, polished aluminium plate in the upper-left corner of the fascia, with the designation 'dual mono integrated amplifier' followed by the Musical Fidelity signature—leaving no room for doubt as to its origin.
A Personal Trainer for Your Music
There is something refreshingly austere about this workhorse robustness that any serious reviewer would want in their arsenal. It grips the speakers and, much like a personal trainer at the gym, compels them to follow the programme until the excess fat is gone, leaving only muscle and elasticity. The dynamics are extraordinary, and there is that rare sensation of music flowing naturally, without any apparent mechanical effort.
The internal topology derives from the Titan platform, introduced by Musical Fidelity in 2008, which is built around a dual-mono configuration and a Darlington output stage, in which pairs of transistors connected in cascade operate as one, but with far greater current gain than a single transistor could achieve.
The power supply follows a classic analogue architecture centred on a toroidal transformer, eliminating the high-frequency noise and electromagnetic interference typically associated with switching-mode power supplies.
Note: The transformer is slightly noisy when the amplifier is first switched on but settles down once it stabilises.
Modern Features
Like its predecessor, the m6si, it retains the XLR inputs and the invaluable MM/MC phono stage, alongside the usual RCA analogue inputs: CD, Tuner, 2 × Aux (one with home-theatre bypass), plus pre-out and line-out. But the m6xi adds HDMI ARC, optical and coaxial digital inputs, and a USB-C digital input (192/24), replacing the more modest USB-B (96/24) found on the m6si.
In other words, Musical Fidelity has equipped the m6xi with all the connections needed to step beyond the world of the purist audiophile and engage with real living rooms in 2026 — including the television, external streamer, PC, subwoofer, AV system (home cinema bypass), and turntable. The telephone is the exception: there is no Bluetooth.
Power and Technology
The rated output is 230W into 8 ohms and 390W into 4 ohms. As if that were not enough, the m6xi can deliver 760W into 2 ohms. A true powerhouse, with sufficient current reserves to handle even the most demanding loudspeakers.
It took hold of my modest Sonus Faber Concertino speakers—small but temperamental—with the same effortless grace with which Prince Siegfried lifts Odette, the White Swan, in Swan Lake. And with a full orchestra in tow, for that matter.
I set the remote aside because I like turning the volume knob myself. I used only two sources: USB and CD. I connected a Node Icon streamer to the USB-C input and my faithful Oppo BDP-95 to the CD input. I found myself preferring the USB-C input, suggesting that Musical Fidelity has addressed the m6si’s DAC shortcomings.
I connected it to a pair of Sonus Faber Concertinos that happened to be on hand. I'm the sort who kicks the ball with the foot more at hand, pun intended. The m6xi has the technique, power, and pace of a top-class centre-forward. It reads the game—the music—and never loses possession, always commanding it with style across the entire pitch.
The m6xi honours the beauty of simplicity and sustains the force of complexity.
The Power of Love
Take Diana Krall's My Love Is: the finger snaps are rendered with remarkable clarity, marking the beat above a well-defined bass line, underpinning the swing in Krall's voice: sweet and sensual, yet with authority and intent.
Sara K., another audiophile favourite, sings I Can't Stand the Rain. The electrified drones of the guitar and harp clear the path for the voice, whilst the bass drum marks the rhythm. Each beat seems to carry its own meaning — distinct in timing and impact — as though it were translating the lyrics Sara is singing into Morse code.
Regarding bass, have you heard Celestial Echo by Malia? It blends natural and synthesised percussion, forming a soft layer of petals upon which Malia writhes and breathes sensuously. The m6xi pushes the little Concertinos further down than they would normally dare whilst keeping a firm, supportive hand beneath them. The low-damping-factor issue with the m6si seems to have been satisfactorily resolved.
A Sunday Kind of Love is a pragmatic love letter, sung live at the Village Vanguard by Mary Stallings and inscribed in an elegant hand by the magical fingers of pianist Eric Reed. The drummer, brushes in hand, and the double bassist seem content merely to appreciate the dialogue between Mary and Eric, maintaining a discreet presence on stage. The audience, naturally, is utterly won over and makes its feelings known with vocal encouragement and applause. As am I. Yeah!
Long After You Are Gone by Chris Jones gives the m6xi the opportunity to reproduce with exceptional fidelity the decay of both low and high guitar notes, which Chris uses like the slow waters of a river to navigate placidly with his melancholic voice. I usually only hear this rendered so well through high-end amplifiers. Is the m6xi a high-end amplifier? Go and listen for yourself.
Conclusion
We could be here all day listening. So allow me to close with the same words I used to describe the B1xi, which shares the same DNA: 'There is a tonal balance here that both honours the beauty of simplicity and sustains the force of complexity.' Beautifully put, indeed. Only the m6xi goes even further—five times further: in power, in quality, and… in price.
The MF m6xi is ideal for loudspeakers that are difficult to get off the ground in terms of sensitivity and impedance—not necessarily in terms of weight…
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