Musical Fidelity M6s Preamplifier

Pure Class A, From Input to Output

Class A is the costly way to build a preamplifier: the circuit stays fully powered at all times, trading efficiency for the sweetest, most immediate sound. Musical Fidelity built the M6s PRE that way from end to end, and made it fully balanced from input sockets to output sockets besides. The measurements reward the extravagance: distortion as low as 0.0004% through the balanced path, signal-to-noise beyond 96dB, and frequency response reaching 80kHz.

The input roster covers a whole system's worth of sources: four RCA line inputs, two balanced XLR inputs, a USB input for computer audio, and a proper MM/MC phono stage with low-noise circuitry and accurate RIAA equalization for any cartridge you run. Home theater bypass on both balanced and line inputs lets a surround processor share your main speakers.

Outputs include balanced XLR and RCA variable pairs, plus a fixed RCA pair for recording, with a stout 19-volt maximum balanced output that will drive any power amplifier, even over long cable runs.

British Build, Serious Scale

The M6s PRE is a full-width, 25-pound component with a custom-extruded aluminum front panel, machined knobs and buttons, and a medical-grade stainless steel badge. It looks and feels like the anchor of a system, because that's the job Musical Fidelity built it for: a preamp to settle into, not upgrade past.

The phono stage deserves its own mention. With 3.5mV moving-magnet and 440-microvolt moving-coil sensitivity, 47k-ohm loading, and a 29dB overload margin, it treats vinyl as a first-class source rather than a checkbox.

What Reviewers Are Saying

The Audio Tailor, in a January 24, 2025 review, called the M6s PRE's sonic signature "nothing short of extraordinary," praising its "outstanding pure Class A performance" and "exceptionally low distortion figures," and concluding it's "a testament to what's possible in modern preamp design" that "will serve as the heart of a high-end system for years to come."

Who Is This Preamplifier Best For?

• You want true Class A sound — the whole circuit runs Class A, not just a marketing sticker.
• You play vinyl with any cartridge — the built-in phono stage handles both MM and MC.
• Your system runs balanced — fully balanced from inputs to outputs, with XLR in and out.
• Your system doubles for movies — home theater bypass works on balanced and line inputs alike.
• If you listen on headphones, the M6s PRE has no headphone jack — Rogue's RP-7v2 builds a tube headphone amp in.

How Does It Connect to Your System?

Connect the balanced XLR or RCA variable outputs to your power amplifier. Your turntable joins the phono input with the MM/MC setting matched to your cartridge, your computer the USB input, and line sources the four RCA and two XLR inputs. A surround processor connects through the bypass for movie nights, and the fixed outputs feed a recorder.

Pure Class A from the first socket to the last, and every source treated like it matters.

Pairs Well With

Building around the M6s PRE? Here are some great companions:

• Turntable: Put the MM/MC phono stage to work — see our Turntables.
• Floorstanding Speakers: Downstream of your power amp — see our Floorstanding Speakers.
• Cables: Quality XLR interconnects feed your power amp — see our Interconnect Cables.
• Audio Rack: Give this full-width Brit a proper home — see our Audio Racks.

Frequently Asked Questions

What does "pure Class A" mean?

The circuit stays fully powered at all times instead of switching, an inefficient but sonically rewarding approach prized in high-end designs.

Can I connect a turntable?

Yes. The built-in phono stage supports both moving-magnet and moving-coil cartridges with accurate RIAA equalization.

Is it fully balanced?

Yes, from the input sockets to the output sockets, with two XLR inputs and XLR variable outputs.

Can I connect a computer?

Yes. A USB type-B input accepts computer-based music directly.

Does it work with a home theater?

Yes. Home theater bypass is available on both the balanced and line-level inputs.

What finishes are available?

Silver or black.

See It in Action

2ndhandhifi looks over the M6s PRE up close:

MR-Max Tube tours the M6s PRE as a system command center:

Why Audio Advisor?

• 40+ Years of Expertise — Since 1981, we've helped over a million music lovers find the right gear.
• 60-Day Money-Back Guarantee — Take your time. Listen, enjoy, and make sure it's right for you.
• Real Experts, Real Help — Our team is here to answer your questions at 800-942-0220, weekdays 9am–6pm EST.
• Free Shipping — On orders over $49, delivered to your door.
• Flexible Payment Options — Financing available so you can start listening now.

Learn More

Want to learn more about preamplifiers, phono stages, or building a balanced system? Visit our Learning Center for guides, tips, and expert advice.