Name: Musical Fidelity B1xi
SKU: MFIB1XI
Availability: BackOrder

Musical Fidelity B1xi

The B1xi integrated amplifier channels Musical Fidelity’s renowned amplifier expertise into a versatile, high-performance package.

Driven by the design principles of their flagship models, the B1xi delivers 100W per channel into 4 ohms through a refined Class A/B circuit, offering a rich and dynamic tube like sound.

Designed for today’s diverse listening needs, it features a comprehensive input selection: MM phono stage, coaxial and optical digital inputs, ARC, Bluetooth, and three RCA line inputs—all engineered for seamless source integration.

A variable RCA pre-out supports subwoofer connection or bi-amping, while a 5V USB-C output provides convenient and clean high-quality power for an external streamer.

Encased in robust all-metal construction with solid metal controls and a solid aluminium front panel, the B1xi offers the sonic and build quality Musical Fidelity is known for, delivering a pure, uncompromised audio experience for discerning music lovers.

Pure Class A/B Excellence with True High-End Audiophile Design

Transistor amps in Class A/B are best after tubes and Class A amps. Musical Fidelity is tube like sound and power.

The B1xi delivers 60 watts per channel into 8 ohms, 100 watts into 4 ohms and 140W peaks into 2 ohms. It won’t struggle to drive a wide range of speakers, even power-hungry models.

Discrete power and toroidal transformer

The fully discrete Class A/B power amp, complemented by its dedicated power supply and generously proportioned toroidal transformer, guarantees reserves for proper peak delivery and a wide dynamic range.

Power hungry and difficult speakers are driven with ease.

Low impedance dips are managed gracefully and the judiciously rated output devices won‘t faulter under any load.

Low noise preamp and phono stage

The preamp section features its own dedicated linear power supply—a rarity in integrated designs.

This separation ensures ultra-low noise and excellent channel separation, rivaling high-end pre/power separates.

Volume control is handled via a motor-driven analogue potentiometer, preserving signal purity—unlike many modern digital volume controls that compromise fidelity due to a loss in signal resolution.

Vinyl lovers will appreciate the B1xi’s exceptionally low-noise, high-gain phono stage.

Carefully tuned for musicality and detail, it brings out the best in your MM cartridges without adding coloration or distortion.

Separate digital boards

Digital and analogue hardware needs to be carefully separated from each other.

Even the smallest amount of RF interference is known to cause trouble for analogue amplifier stages.

Therefore, the digital and ARC boards are physically separated on their own PCBs and have their own linear power supply.

Drawing from their decade long experience in designing DACs (recently with their ground-breaking Nu-Vista DAC and M8x DAC), the B1xi uses a carefully trimmed DAC design using the superb ESS9018 chip.

The digital coaxial and optical inputs accept high-resolution sample rates up to 24bit and 192kHz and the ARC ARC input allows your home theatre to be brought to life and properly invigorated by the powerful B1xi

Analogue amp stages.

Uncompromisingly heavy mechanical design

The inclusion of high-end elements such as the robust metal controls, extruded aluminium front panel, and a chassis crafted entirely from metal, the B1xi occupies an enviable position for discerning audiophiles seeking an unadulterated high-end amplifier.

Specifications Musical Fidelity B1xi

Amplifier

Power, both channels driven @ 1% THD: 60 Watts per channel into 8 Ohms; 100W into 4 ohms; 140W peaks into 2 ohms
Power, both channels driven @ 0.09% THD, 20Hz to 20 kHz: 50 Watts per channel into 8 Ohms; 80W into 4 ohms
Voltage 21 Volts RMS, 20Hz to 20 kHz; onset of clipping
30 Volts peak to peak
Current 8 Amps peak to peak
Damping factor 30
Output devices 1 pair per channel

Line input

THD+N < 0.02 % typical, 20Hz to 20 kHz

Signal/ noise ratio> 100dB ‘A’ weighted

Input impedance 47k Ohms

Frequency response +0,–3dB, 10Hz to 30kHz

Phono input

Sensitivity (nominal): 5mV (suitable for cartridges giving 1.5mV or more including high output MC types)
Signal / noise ratio: >70dB ‘A’-weighted
Input impedance: 47k Ohms
Input capacitance: <100pF
Gain: 42dB
Frequency response: RIAA/IEC ±1dB, 20Hz to 20 kHz

Connections

Line level inputs 3 pairs line level RCA connectors
MM phono input
Optical, coaxial, ARC digital inputs (up to 24bit/192kHz stereo PCM)
Bluetooth 5.1 input
1 pair line level RCA connectors, preamp outputs for e.g. bi-amping
Speaker outputs 1 pair 4mm banana plug/ binding posts

Power requirement

Mains voltages 115/230VAC 50/60Hz (factory pre-set)
100VAC 50/60Hz (alternative)
Consumption 280 Watts maximum

Weight

Unit only, unboxed 7.2 kg
In shipping carton 8.9 kg

Dimensions

Wide 430 mm
High, including feet 90 mm
Deep (front to back) including terminals 324 mm

Brand

Musical Fidelity

Musical Fidelity has been designing and manufacturing Hi-Fi electronics for over thirty years and are proud to have become one of the best-known brands in the Hi-Fi industry. They are driven by a passion for wonderful music and the challenge of world-class engineering. They approached each new design by looking for the absolute best solution to a given challenge and embrace new technologies in our designs as well as developing more traditional methods for even greater performance. 1982 Their first product - The Preamp – launched to rave reviews. Followed by shoebox-style Dr Thomas power amp. 1984 Launch of A1 integrated amp, ‘the most important development so far in the renaissance of the UK hi-fi scene’ (Hi-Fi Answers). 1986 New A370 Power Amp proclaimed ‘the best power amp I’ve ever heard’ (Hi-Fi Answers). 1987 World’s first high-end DAC- Digilog – makes debut 1988 Another world first: MVX preamp, combining tube circuit topology with transistors. SA470 launched: 86Kg power amp running 99% in Class A 1992 A1000 integrated released, featuring pure Class A power amp section 1993 Classic valve-driven Tubalog DAC goes on sale 1995 X Series launches with X-10D Class A triode line stage: ‘the most dramatic sonic enhancement you’re likely to hear!’ (F1). 1997 Nu-Vista Preamp launched, using miniature, metal-cased nuvistor tubes. All 500 units sold within three months. X Series expands with X-ACT DAC, praised for 'smooth, easy-going sound' (What Hi-Fi?) 1998 X-24K upsampling DAC released: ‘capable of getting sound to die for’ (Stereophile). X-Ray CD player launched. Described as ‘the sort of object you just want to fondle’ (Hi-Fi News) ‘a thrilling, substantial and satisfying listen’ (What Hi-Fi?) and ‘Hi-Fi meets nuclear warhead’ (T3). 2000 Futuristic CD-PRE 24 arrives, combining a high-quality CD transport, DAC and preamp. On Hi-Fi says it ‘represents a combination of features, functional performance and affordability that seems an audiophile dream come true’. Debut of Musical Fidelity Nu-Vista M3 pre/power amp, including discrete Nu-Vista power amp modules with choke regulation. ‘This is what hi-fi should be all about’ (Gramophone). X-DAC V3 released, offering ‘stunningly good measured performance’ (Stereophile). 2002 World’s first audio application of trivistor tubes in new Tri-Vista series, including legendary Tri-Vista 21 ‘Super DAC’. 2003 Flagship kW pre-amp and kW power amp launched: ‘the very finest amps you can buy...the MFs redefine audio standards’ (What Hi-Fi?) Next up: kW 500 super integrated amp with twin-triode tubes. Hi-Fi News said, ‘For one rare reviewing occasion I could not find a thing to fault about the musical presentation of an amp’. Limited-edition M1 turntable released. Considered one of the best-engineered decks ever, it’s now a collector’s item, fetching above its original price. 2004 Supercharged X-DAC V8 introduced, with switchable tube buffer and extra-heavy-duty power supply. ‘For its superb performance as a detailed, sweet-sounding DAC, the X-DAC V8 stands on its own’ (Stereophile). X-150 wins European Stereo Amplifier of the Year, EISA Awards 2004-2005. 2006 Debut of kW250S one-box wonder, packing in dual 250-watt monobloc amps, tube hybrid preamp, phono stage, 24-bit 192K upsampling CD player, FM/DAB tuner and iPod input. 2009 Meet the mighty TITAN: 1kW per channel dual monobloc design with external power supply. Hi-Fi News was ‘Smitten… The Titan is the best power amplifier I’ve used’. Reference-standard Primo pre-amplifier released; pure Class A with 14 hand-picked ECC81 2011 New M1 CLiC unites analogue and digital sources under universal control. Wins European Network Music Player, EISA Awards 2011-2012. 2012 Line-up expands to meet every hi-fi need and budget. Highlights include the AMS CD/DAC – our finest digital product yet - and AMS100, the world’s most advanced pure Class A amp

Now owned and operated by Audio Tuning, an independent audio specialist company based in Austria, Musical Fidelity still retains its proud British heritage, with every product we design continuing to boast the natural, authentic sound that has made our name so respected across the world. Our unique ranges embrace both traditional and modern requirements. So whether you need a high-quality phono stage to improve your vinyl listening experience, require bit-perfect playback of your beloved CDs, or have chosen to embrace the increasingly popular world of wireless music streaming, we have something to offer. And for every source, we’re still proud to boast a wide range of powerful, state-of-the-art amplifiers that sound at home anywhere. Whatever type of music you enjoy and however you want to hear it, we have something for you at Musical Fidelity.