Musical Fidelity M3x DAC Digital-to-Analog Converter - Black

A Full-Width DAC That Does One Job Properly

The Musical Fidelity M3x DAC is a converter and nothing else. No streaming board, no app, no headphone stage sharing the power supply. A PCM1795 does the conversion, an SRC4392 handles upsampling ahead of it, and the whole chassis exists to serve those two chips.

Five inputs sit on the back. Two coaxial and two optical take 24-bit/192kHz, and a USB Type B input handles 32-bit/192kHz PCM plus DSD256 in both DoP and native form. Everything in the rack can stay plugged in.

Balanced Outputs at a Sensible Price

Both output conventions are here: a balanced XLR pair at 4V and a single-ended RCA pair at 2V. Each switches between fixed and variable, so the M3x can feed a preamplifier or drive a power amplifier directly and save you a box.

Each analog output stage has its own buffer, built for low noise and enough current to hold up over a long cable run. Output impedance stays under 50 ohms, which means the input stage downstream is not being asked to work around the source.

What the Upsampling Is Actually Doing

Incoming PCM is reclocked and upsampled to 192kHz before it reaches the converter, which moves the filtering further away from the audible band. DSD, by contrast, plays in its native form rather than being converted to PCM first.

The Numbers Behind the Quiet

Signal-to-noise measures better than 107dB A-weighted at 1kHz, distortion under 0.005%, and channel separation better than -115dB at 10kHz. Jitter is held under 48 picoseconds peak to peak and linearity holds within 0.2dB down to -100dB.

Frequency response runs -0.2dB at 20Hz and 0.1dB at 20kHz, and is still within 1.5dB at 70kHz. The chassis is a full-width 440 by 100 by 363mm at 6.8kg, drawing 15 watts at most and under half a watt in standby.

Who Is This DAC Best For?

• You want a converter, not a Swiss army knife — the budget went into conversion and analog output stages rather than into features you would switch off anyway.
• You have four digital sources — two coaxial and two optical inputs plus USB mean the streamer, disc player, television and computer all keep a permanent home.
• Your amplifier has balanced inputs — the 4V XLR pair uses them properly, and the fixed-or-variable switch decides which box holds the volume control.
• You play DSD as well as PCM — DSD256 arrives over USB in native form or as DoP, so nothing is converted to PCM on the way in.
• If you listen in headphones, plan for an amplifier — the M3x is a line-level converter with no headphone socket. Pair it with one of our Headphone Amplifiers and the RCA output feeds it directly.

How Does It Connect to Your System?

Computer on USB, streamer on one coaxial, disc player on the other, television and console on the optical pair. Out the back, run XLR to a balanced amplifier or RCA to anything else, then set the output switch to fixed if your amplifier is handling volume and variable if you want the M3x to.

After that it is a component you stop thinking about, which is the point.

Pairs Well With

Building a system around the M3x DAC? These are the natural companions:

• Music Streamer: Puts your library on the coaxial or USB input — see our Music Streamers.
• Headphone Amplifier: The box the RCA output is looking for — see our Headphone Amplifiers.
• Interconnects: Balanced XLR cables to make use of the 4V output — see our Interconnect Cables.
• Audio Rack: A full-width shelf for a full-width box — see our Audio Racks.

Frequently Asked Questions

Which digital inputs does it have?

Two coaxial, two optical and one USB Type B. The coaxial and optical inputs handle 24-bit/192kHz stereo PCM.

What does the USB input support?

32-bit/192kHz stereo PCM and DSD256, both as DoP and native, over USB Audio Class 2.0.

Can it drive a power amplifier directly?

Yes. Set the XLR or RCA outputs to variable and the M3x controls the level. Set them fixed and volume stays with your preamplifier or integrated amp.

What are the output voltages?

4V RMS at 0dBFS from the balanced XLR pair and 2V RMS from the RCA pair, with output impedance under 50 ohms.

How much power does it use?

Fifteen watts at maximum and under half a watt in standby, so it can be left switched on without a second thought.

See It in Action

AV Atmos introduces the M3x and where it sits against the pricier M6x:

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Learn More

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