NAD Masters M66 BluOS Streaming DAC-Preamplifier

NAD Put the Whole Front End in One Masters Chassis

The Masters M66 is NAD's flagship stereo preamplifier. It is a BluOS streamer, an ESS Sabre DAC, an MM and MC phono stage, and a headphone amplifier in one box. A 7-inch color touchscreen runs the front panel, and the BluOS app mirrors it.

The input list is long. Analog covers RCA, balanced XLR and the phono stage. Digital covers HDMI eARC, AES/EBU, USB, coaxial and optical, plus Bluetooth 5.0 with aptX HD. Balanced and unbalanced outputs feed your power amplifier.

Four Subwoofer Outputs, and Dirac to Set Them Up

Four configurable subwoofer outputs are fitted. A Dirac Live Full Bandwidth license is included, along with the calibration microphone, so room correction and Dirac Live Bass Control are ready to run out of the carton with nothing else to buy.

BluOS handles multiroom streaming and the services you already use, including Qobuz Connect. The M66 is Roon Ready and decodes MQA. Dual MDC slots leave room for NAD to add capability later without replacing the chassis.

Where the Analog Path Stays Out of the Way

An ESS Sabre ES9038PRO handles digital-to-analog conversion, with an ES9022PRO on analog-to-digital duty. Analog sources can pass through untouched, or be digitized so Dirac and bass management can work on them. That choice is yours per input.

NAD rates distortion below 0.001 percent at 2V out through the preamplifier. Feed it on AES/EBU or USB and that figure drops below 0.0005 percent. Channel separation beats 120dB at 1kHz, and response holds 20Hz to 20kHz within 0.2dB.

The Numbers That Matter When You Add a Power Amp

Signal-to-noise on the analog inputs is better than 105dB, referenced to 500mV out at unity gain. Output impedance is the source impedance plus 22 ohms, low enough for long cable runs. The chassis is 17 1/8 by 5 1/4 by 15 15/64 inches and weighs 16.7 pounds.

NAD covers the M66 for two years, parts and labor. Digital handling includes DDH, which manages intersample overs rather than letting them clip. It is the kind of detail that only shows up on the bench, and it is the reason the meters stay honest.

What Reviewers Are Saying

Roger Kanno reviewed the M66 for SoundStage! Hi-Fi on 1 September 2024 and gave it a Reviewers' Choice award, concluding that "I cannot think of another product at a comparable price that comes close to the M66 in performance and flexibility".

Isaac Adams reviewed it for Home Theater HiFi on 23 June 2025. He wrote that the M66 "offers unique features, delivered masterfully, for a price that is reasonable given what you get" after months with the unit.

Adams did name one thing he would change. On his wish list was "An option to increase the 15-minute limit on the auto power-down timer when no signal is detected". If you leave a source paused for long stretches, expect the M66 to switch itself off.

Who Is This Preamplifier Best For?

• You are building around separates and want one front end — streaming, conversion, phono and headphones all live in one chassis, so the only box left to choose is the power amplifier and the rack loses three sets of interconnects.
• You play records and your cartridge might change — the phono stage handles both moving magnet and moving coil, so a cartridge upgrade later needs no outboard stage and no rethinking of the front end.
• You run more than one subwoofer — four configurable outputs and Dirac Live Bass Control are included with the microphone, so multiple subs integrate properly without hiring a calibrator or buying a processor.
• Your television is part of the system — HDMI eARC is fitted alongside AES/EBU, USB, coaxial and optical, so the TV feeds the same DAC as everything else and you stop switching between two systems.
• You want to choose the power amplifier — the M66 switches, converts, corrects and controls; pair it with our stereo amplifiers

How Does It Connect to Your System?

A turntable goes to the phono input, set for moving magnet or moving coil. Line sources fill the RCA and XLR inputs. A television connects on HDMI eARC, a CD transport on coaxial or optical, and a computer or studio source on USB or AES/EBU.

Balanced or unbalanced outputs run to your power amplifier. Up to four subwoofers connect to the dedicated outputs, and Dirac Live Bass Control blends them with the main speakers. Run the calibration microphone once and the corrections are stored.

Pairs Well With

Building a system around the Masters M66? Start here:

• Power Amplifier: The one box the M66 does not replace — browse Amplifiers.
• Turntable: Moving magnet or moving coil, the stage is built in — browse Turntables.
• Subwoofers: Four outputs and Dirac Bass Control are waiting — see our Subwoofers.
• Interconnects: Balanced runs suit a preamp this quiet — see Interconnect Cables.

Frequently Asked Questions

Is the room correction microphone included?

Yes. The M66 ships with a Dirac Live Full Bandwidth license and the calibration microphone, so room correction and Dirac Live Bass Control are ready to run.

Which cartridges does the phono stage accept?

Moving magnet and moving coil both. The stage is built in, so no outboard phono preamplifier is needed for either type.

How many subwoofers can it drive?

Four, each on its own configurable output, integrated by Dirac Live Bass Control.

Does it work with Roon and MQA?

Yes. The M66 is Roon Ready and decodes MQA. BluOS covers multiroom streaming and services including Qobuz Connect.

Can I connect my television?

Yes, over HDMI eARC. AES/EBU, USB, coaxial and optical cover the rest of your digital sources, and Bluetooth 5.0 with aptX HD handles casual listening.

What does the warranty cover?

NAD covers the M66 for two years, parts and labor. Confirm registration requirements with us before you buy.

See It in Action

Audioholics walks through the M66's Dirac implementation and its four subwoofer outputs:

Darko Audio puts the Masters M66 in the context of NAD's range:

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 streaming preamplifiers, Dirac Live room correction, or subwoofer bass management? Visit our Learning Center for guides, tips, and expert advice.