Description
B1xi
Released in July 2025, 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.
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, uncompromising audio experience for discerning music lovers.
Designed for today’s diverse listening needs, B1xi 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, whilst a 5V USB-C output provides convenient and clean high-quality power for connecting an external streamer.
Power Amp
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.
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.
Preamp
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, rivalling 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.
MM Phono Stage
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.
Digital Section
The digital and ARC boards are physically separated on their own PCBs and have their own linear power supply. Drawing from decades-long experience in designing DACs (recently with the 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 24-bit / 192 kHz and the ARC ARC input allows your home theatre to be brought to life and properly invigorated by the powerful B1xi analogue amp stages.
No WiFi By Design
B1xi features no WiFi streaming on purpose. There has been a surge in offerings from Hi-Fi companies with all-in-one solutions and unfortunately, such developments often prove to be expensive and maintenance-heavy.
MF believe that fast-moving streaming technology is best kept separate and therefore will not negatively impact the lifecycle of the B1xi. For that reason, the B1xi features a high-quality isolated USB C 5V power output for your favourite modern streamer – effectively also doubling as a power supply upgrade.
B1xi Integrated Amplifier, in Black finish, by Musical Fidelity.
Features
- Fully discrete transistor based Class A/B power amp design in Musical Fidelity tradition.
- Drives power hungry speakers with ease.
- Low noise design for best THD and signal integrity at low as well as high levels.
- High quality motor-driven analogue potentiometer.
- Pre out for bi-amping or active subwoofer connection.
- MM phono stage included.
- Separate digital and ARC boards with own linear PSU.
- Up to 24-bit / 192 kHz Stereo PCM, via Coaxial, Optical, and ARC inputs.
- Bluetooth 5.1 input.
- Independent power supplies for preamp, power amp and digital section.
- 5V USB-C power output to drive most new modern external streamers.
- Uncompromising build quality and components.
Specifications
- Power: 60 W per-channel into 8 Ohms, 100 W per-channel into 4 ohms, 140 W peaks into 2 ohms (both channels driven @ 1% THD)
- Voltage: 21 V RMS, 20 Hz to 20 kHz, onset of clipping, 30 V peak to peak
- Current: 8 A peak-to-peak
- Damping Factor: 30
- Output Devices: 1 pair per-channel
- Line Input
- THD+N: < 0.02 % typical, 20 Hz to 20 kHz
- SNR: > 100 dB, A-weighted
- Input Impedance: 47 kOhms
- Frequency Response (+0, –3 dB): 10 Hz to 30 kHz
- Phono Input
- Sensitivity (nominal): 5 mV (suitable for cartridges giving 1.5 mV or more, including high output MC types)
- SNR: > 70 dB, A-weighted
- Input Impedance: 47 kOhms
- Input Capacitance: < 100 pF
- Gain: 42 dB
- Frequency Response (RIAA / IEC ±1 dB): 20 Hz to 20 kHz
- Connections
- 3 x Pairs RCA Line level
- 1 x MM phono input
- 1 x Optical, 1 x Coaxial, 1 x ARC digital inputs (up to 24-bit / 192 kHz stereo PCM)
- 1 x Pair line level RCA connectors, preamp outputs for e.g. bi-amping
- Bluetooth 5.1 input
- 1 x USB-C Output, 5 V
- 1 x Pair Speaker Outputs, 4 mm banana plug / binding posts
- General
- Mains Voltages 115 / 230 V AC, 50 / 60 Hz (factory preset), 100 V AC 50 / 60 Hz (alternative)
- Power Consumption: 280 W Max
- Weight: 7.2 kg (Boxed 8.9 kg)
- Dimensions (W x H x D): 430 x 90 x 324 mm
Included
- 1 x B1xi Integrated Amplifier
- 1 x Power Cable
- 1 x Documentation
Full Musical Fidelity Range Available
Unilet Sound & Vision are official retail partners for Musical Fidelity, providing sales, advice and assistance on their entire range of high-quality products. Please do get in touch if you would like a demonstration or wish to purchase.
