Musical Fidelity M8x DAC - 32 Bit Dual Mono Design

The Converter at the Top of the M Range

The Musical Fidelity M8x DAC is the full-width, 10.6kg statement of the range. Two ES9038Q2M chips run in dual mono, and the analog stages behind them are given room a smaller chassis simply does not have.

Connection is not a constraint here. Three optical inputs, a coaxial, an AES/EBU, a USB Type B and an I2S input all sit on the back panel. The S/PDIF and AES inputs handle 24-bit/192kHz and MQA to 384kHz; USB goes to 768kHz PCM and native DSD512.

A Headphone Amplifier That Deserves the Name

Two headphone outputs sit on the front: a 6.3mm jack and a four-pin XLR for balanced cables. The amplifier behind them delivers 3.9 watts into 8 ohms, 3.2 watts into 32 ohms and 400mW into 300 ohms. Very little in a headphone catalog asks for more than that.

The line outputs cover both conventions, with a balanced XLR pair at 4V and an RCA pair at 2V. Each switches between fixed and variable, so the M8x can be a source or the volume control for the whole system.

Femtoseconds, and Why They Matter Here

Jitter is held under 100 femtoseconds peak to peak. That is timing error measured in quadrillionths of a second. It is the figure that separates a converter which merely reads the data from one that reads it on schedule, and it is the hardest of these numbers to buy cheaply.

The Rest of the Bench Sheet

Distortion measures under 0.001% at 1kHz and signal-to-noise better than 100dB A-weighted. Frequency response stays inside 0.1dB from 10Hz to 20kHz, channel separation reaches -114dB at 10kHz, and output impedance sits under 100 ohms.

Eight digital filters are on hand for the converter section. The I2S input carries a 16.9344MHz master clock output for a compatible transport, which is the connection that keeps clocking duties in the DAC rather than the disc player.

The chassis measures 483 by 102 by 381mm and draws 70 watts at maximum. It is built for a rack shelf that was designed for amplifiers rather than for source components.

What Reviewers Are Saying

Phil Wright of The Absolute Sound, in a March 4, 2026 review, concluded: "The M8x is a stonking fixed-output DAC, combining strong detail retrieval with a powerful low end and a lovely organic sound."

Who Is This DAC Best For?

• You run demanding headphones — 3.9 watts into 8 ohms and a balanced four-pin XLR mean planars and high-impedance dynamics are both handled without a second amplifier.
• Your rack is full of digital sources — three optical, coaxial, AES/EBU, USB and I2S mean nothing gets unplugged to make room for something else.
• You want the DAC to run the system — switch the XLR or RCA outputs to variable and a power amplifier connects directly, with no preamplifier in the path.
• You buy at the top of a range and keep it — dual-mono conversion, sub-100-femtosecond jitter and a 10.6kg chassis are what you are paying for, and none of it dates quickly.
• You want to choose the streamer separately — one of our music streamers feeds the M8x's digital inputs and it handles the conversion

How Does It Connect to Your System?

Computer on USB, streamer on AES/EBU or coaxial, TV and console on the optical inputs, and a compatible transport on I2S. Out the back, balanced XLR to a power amplifier or RCA to an integrated. Set fixed or variable depending on which box you want holding the volume control.

Headphones go in the front, balanced or single-ended. Nothing else needs buying.

Pairs Well With

Building a system around the M8x DAC? These are the natural companions:

• Headphones: The balanced XLR output is built for a serious pair — see our Headphones.
• Music Streamer: Puts your network library on the digital inputs — see our Music Streamers.
• Interconnects: Balanced XLR cables for the run to your amplifier — see our Interconnect Cables.
• Audio Rack: A shelf that will take the weight — see our Audio Racks.

Frequently Asked Questions

Which digital inputs does it have?

Three optical, one coaxial, one AES/EBU, one USB Type B and an I2S input for a compatible transport.

What resolution does each input handle?

Optical, coaxial and AES/EBU run to 24-bit/192kHz, MQA to 384kHz and DSD64 over DoP. USB reaches 768kHz PCM, DSD256 over DoP and native DSD512.

Which headphone connections are on the front?

A 6.3mm single-ended jack and a four-pin XLR balanced socket, both fed by the same Class A circuit.

Can it drive a power amplifier directly?

Yes. Set the XLR or RCA outputs to variable and the M8x controls volume. Set them fixed and a preamplifier downstream takes over.

How much room does it need?

483 by 102 by 381mm and 10.6kg, so a full-width shelf rated for an amplifier rather than a source component.

See It in Action

Watch this product-focused video:

Mad Audio examines this model:

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Learn More

Want to learn more about DACs, balanced headphone connections, or I2S digital connections? Visit our Learning Center for guides, tips, and expert advice.