Musical Fidelity M6xi Integrated Amplifier

A fully discrete dual-mono, 220 Wpc integrated amp with DAC, HDMI eARC, USB-C, MM/MC phonostage, and balanced XLR input

The Musical Fidelity M6xi is a high-power integrated amplifier built around 2 independent monobloc power amps with a separate preamp stage in a shared chassis. Its fully analog amplifier design uses circuitry derived from Musical Fidelity’s TITAN power amplifier, with a low-distortion output stage arranged to avoid crossover artifacts and preserve control into demanding loudspeaker loads.

The M6xi delivers 220 W per channel into 8 ohms and 320 W per channel into 4 ohms, with substantial current capability and power reserves for wide dynamic range. Its PCB layout is designed to reduce circuit imbalances that would otherwise require corrective feedback, while the oversized encapsulated toroidal transformer and analog power supplies help reduce high-frequency noise and electromagnetic interference.

Connectivity has been updated for modern systems, with HDMI eARC, coaxial, optical, and USB-C digital inputs, plus a balanced XLR input, 4 line-level RCA inputs, and an upgraded MM/MC phonostage. A home-theater bypass input allows the M6xi to serve as the front left/right amplifier in a multichannel system, while preamp outputs support bi-amping or active subwoofer integration.

Fully Discrete Power Amplifier

The M6xi is configured as 2 independent monobloc power amplifiers with a separate preamp stage, effectively combining a preamp and 2 power amps in one chassis. The amplifier stage uses Musical Fidelity’s classic low-distortion output topology and incorporates technology from the company’s TITAN amplifier platform.

Power delivery is central to the design. The M6xi provides 220 Wpc into 8 ohms, 320 Wpc into 4 ohms, and 45 amps peak-to-peak current, giving it the headroom and control needed for difficult speaker loads and low-impedance dips.

Modern Inputs and System Integration

The M6xi adds HDMI eARC for TV and home-theater use, along with coaxial, optical, and USB-C digital inputs supporting up to 24 bit/192 kHz resolution. RS232 control allows integration into custom-installed systems, and a 5 V/2 A USB-A power output provides a clean power source for compatible external streamers.

The home-theater bypass input bypasses the preamp stage, allowing the M6xi to operate as a high-performance stereo power amplifier for the front left and right channels in a multichannel system. Fixed line outputs and variable preamp outputs provide additional flexibility for headphone amplifiers, external power amps, or active subwoofers.

Phonostage and Digital Separation

The built-in MM/MC phonostage has been upgraded with improved PCB layout, isolation, and shielding to reduce noise and distortion. The transformer and power supply PCB are encapsulated in a metal enclosure to reduce electromagnetic interference throughout the amplifier, with particular benefit to the high-gain phonostage circuitry.

Digital and analog sections are physically separated on dedicated PCBs, with the digital and ARC boards using their own linear power supply. This separation is designed to reduce RF interference and protect the sensitive analog signal path.

Build Quality

The M6xi’s mechanical construction follows Musical Fidelity’s traditional all-metal approach, with heavy front and side panels milled from extruded aluminum profiles. The rigid aluminum casework helps reduce the effects of vibration while also acting as a shield against electromagnetic interference.

Specifications

Power Output (8 ohm, 4 ohm): 220 W, 320 W

Continuous Power (8 ohm, 4 ohm, 20 Hz–20 kHz, 0.09% THD): 210 W, 300 W

Peak Power (8 ohm, 4 ohm): 280 W, 450 W

Output Voltage: 43 V RMS, 20 Hz–20 kHz at onset of clipping

Peak-to-Peak Voltage: 121 V

Peak-to-Peak Current: 45 A

Damping Factor: 49 into 8 ohms

Output Devices: 2 pairs per channel

Line Input THD+N: <0.007% typical, 20 Hz–20 kHz

Signal-to-Noise Ratio: >107 dB, A-weighted

Line Input Impedance: 40 kΩ

Frequency Response: +0, –0.1 dB, 10 Hz–20 kHz

Analog Inputs: 4 x stereo RCA line-level, 1 x stereo balanced XLR, 1 x MM/MC phono

Digital Inputs: 1 x HDMI eARC, 1 x coaxial, 1 x optical, 1 x USB-C, up to 24 bit/192 kHz

Analog Outputs: 1 x stereo RCA fixed line output, 1 x stereo RCA preamp output

Speaker Outputs: 2 pairs 4 mm banana/binding posts

Control: RS232 D-sub connector

USB Power Output: 5 V/2 A USB-A

Phono Sensitivity (MM, MC): 3 mV, 0.4 mV

Phono Gain (MM, MC): 40 dB, 60 dB

Phono Signal-to-Noise Ratio: >87 dB, A-weighted

Phono Input Capacitance: 220 pF

Phono Input Impedance (MM, MC): 50 kΩ, 1 kΩ

Phono Frequency Response: RIAA/IEC ±0.4 dB, 20 Hz–20 kHz

Power Requirement: 115/230 V AC, 50/60 Hz, factory pre-set

Power Consumption: 680 W maximum

Dimensions (WHD): 17.3" x 4.9" x 15.7" (440 x 125 x 400 mm)

Weight: 40.8 lb. (18.5 kg)