Musical Fidelity B1xi - Integrated Amplifier

The B1xi integrated amplifier delivers Musical Fidelity's renowned amplifier expertise in a versatile, high-performance package. Building on the design principles of our flagship models, the B1xi delivers 100W per channel into 4 ohms through a refined Class A/B circuit, delivering rich, dynamic, tube-like sound.

Designed for today's diverse listening needs, it offers a comprehensive selection of inputs: a moving magnet phono stage, coaxial and optical digital inputs, ARC, Bluetooth, and three RCA line inputs, all designed for seamless source integration. A variable RCA pre-out supports subwoofer connection or bi-amping, while a 5V USB-C output provides convenient, clean, high-quality power for an external streamer. Encased in a rugged all-metal chassis with solid metal controls and a solid aluminum front panel, the B1xi delivers the sound and build quality Musical Fidelity is known for, delivering a pure, uncompromising audio experience for the most discerning music lovers.

Pure Class A/B excellence with high-quality audiophile design

After tube and Class A, Class A/B transistor amplifiers are the next best thing. Musical Fidelity delivers tube-like sound and power. The B1xi delivers 60 watts per channel into 8 ohms, 100 watts into 4 ohms, and 140 watts peak into 2 ohms. It will have no trouble driving a wide range of speakers, even the most power-hungry ones.
Discrete and toroidal power transformer

The fully discrete Class A/B power amplifier, combined with a dedicated power supply and generously sized toroidal transformer, provides reserves for adequate peak output and a wide dynamic range. The most demanding and difficult-to-drive speakers are driven with ease. Impedance drops are elegantly handled, and the appropriately sized output devices perform flawlessly under any load.

Low-noise preamplifier 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 preamps/amplifiers. Volume control is managed by a motorized analog potentiometer, preserving signal purity, unlike many modern digital volume controls that compromise fidelity due to loss of signal resolution. Vinyl lovers will appreciate the B1xi's high-gain, ultra-low-noise phono stage. Carefully tuned for musicality and detail, it brings out the best in your moving magnet cartridges without adding coloration or distortion.
Separate digital cards

Digital and analog hardware must be carefully separated from each other. It's well known that even the slightest RF interference can cause problems for the analog amplifier stages. Therefore, the digital and ARC boards are physically separated on separate PCBs and have their own linear power supplies.

Drawing on our decades of experience designing DACs (most recently with our groundbreaking Nu-Vista and M8x DACs), the B1xi employs a carefully refined DAC design utilizing the superb ESS9018 chip. Coaxial and optical digital inputs accept high-resolution sampling rates up to 24-bit 192kHz, while the HDMI ARC input lets you bring your home theater to life and power it up to the full potential thanks to the B1xi's powerful analog amplifier stages.

Robust and uncompromising mechanical design

The inclusion of high-end features such as robust metal controls, an extruded aluminum front panel, and an all-metal chassis gives the B1xi an enviable position for discerning audiophiles looking for a pure high-end amplifier.

No Wi-Fi on purpose

The B1xi focuses on sound quality, rather than Wi-Fi, display, and apps. Wi-Fi streaming is intentionally NOT included. We've seen a surge in all-in-one solutions from HiFi companies, and unfortunately, these developments are HUGELY EXPENSIVE and, more importantly, require a lot of maintenance.

As a result, manufacturers have started cutting corners: cheap plastic cabinets, low-cost digital amplifiers, and cheap power supplies. Musical Fidelity stands for sound quality and robust design that lasts decades. We invest our money and resources in high-end hardware and the pursuit of optimal music reproduction. This means: robust mechanics - discrete circuitry - large transformers - Class A/B amplifiers. Rapidly evolving streaming technology is best kept separate so it doesn't negatively impact the B1xi's lifespan. For this reason, the B1xi features a high-quality, isolated 5V USB-C power output for your favorite modern streamer, which also serves as a spare power supply.
The audiophile truth

Any RF frequency affects the performance of the analog amplifier. Therefore, our design team, led by Chief Technical Director Simon Quarry:
He spent a year improving the circuit layout and adapting the boards to the transformer
carefully selected components for long-term availability and reliability, to avoid any changes that would require a product redesign
shielded the RF and positioned the boards to avoid interference with the analog stages