NAD Masters Series M33 streaming integrated amplifier Associated Equipment

Sidebar 2: Associated Equipment

Digital sources: Oppo Digital UDP-105 universal disc player, Baetis Prodigy X PC-based music server running JRiver Media Center v26 and Roon, Pink Faun 2.16x Linux-based music server running Roon, Mytek Brooklyn, exaSound e38 Mark II and Okto DAC8 Pro D/A processors. QNAP TVS-873 NAS.
Preamplifier: Audio Research MP1.
Power amplifiers: Benchmark AHB2, Classé Sigma Mono.
Loudspeakers: Revel Ultima2 Studio (L/C/R), Revel Performa3 F206 (SL/SR), 2 JL Audio f110v2 and 1 JL Audio e110 subwoofers.
Cables: Digital cables: AudioQuest Coffee (USB). Analog interconnects: AudioQuest Earth/DBS balanced, Kubala-Sosna Anticipation (RCA). Speaker cables: Benchmark Studio&Stage (NL2 to banana), Canare 4S11 (Blue Jeans Cable). AC cables Kubala-Sosna Emotion, Signal Cable MagicPower 20A.
Accessories: AudioQuest Niagara 5000 and Brick Wall 8RAUD power conditioners, Teddy Pardo 12V PS (for exaSound e38), HDPLEX 400W ATX Linear Power Supply and CyberPower 850PFCLCD AC filter (for the Baetis server).
Listening room: 24' L × 14' W × 8' H, furnished with 2 MSR Acoustics Dimension4 SpringTraps in the front corners, 2 Ready Acoustics Chameleon Super Sub Bass Traps to the sides and moderately sound-absorbing furniture. Front wall has large windows partly covered by fabric drapes and 4" thick 2' × 4' OC 705 panels. Rear of room opens into 10' × 7' foyer and a 12' × 8' dining area.—Kalman Rubinson

NAD Electronics International
633 Granite Ct.
Pickering, Ontario L1W 3K1
(905) 831-6555

a.wayne's picture

Hello John ,

I still Can’t wrap my head around how badly Class D amplifiers measure on square-waves , Thinking this must lead to why most hear odd timbre from them especially on difficult to drive loudspeakers ..

MZKM's picture

A square wave mostly shows frequency range. This amp reaches the bottom of the graph at 50kHz, so naturally the square wave won’t look as good as an amp that is flat to 100kHz. A square wave is made up by adding harmonics of sine waves, so naturally if the harmonics are lower in level, it’ll look less like a square wave. A square wave doesn’t tell us anything that can’t be obtained from other graphs.

Go back to last measurements and you’ll see the same thing, the amps that can get close to a square wave have an extended frequency response. So, you have to believe that we can hear >20kHz in order to believe a difference in quality can be obtained by having a better looking square wave.

As for difficult to drive speakers, that is based on their impedance/phase. Two amps could have identical wattage using 4ohm load test, but the actual wattage available could be drastic if the speaker has say -45° phase and 4ohm and 100Hz. The tonal balance can also be altered by having low output impedance (low damping factor).

modern audio lovers's picture

Great review as always Kal!

Question for John: Is there a reason for using the analog input for the THD+Noise tests on integrated amplifiers that digitize their inputs?

These new breed of devices are obviously designed with playback of digital sources at the forefront. I think that publishing the end-to-end measurements for digital audio input -> amplifier output would serve the best educational interests for the readership-at-large.

This isn't to say that the analog input -> amplifier output measurement isn't useful... would be great to have both!

stereophileuser2020's picture

Looks fantastic, but I'm really disappointed that the M33 doesn't have a USB-B input for hooking up a computer. That's almost a dealbreaker for me.

mtrot's picture

Same here, deal breaker for me.

tonykaz's picture

High-End performance for everyman annnndddddd at everyman's price, egads, this device drove your Revels to convince even you, phew!

I'm wondering, what reward comes from spending 10x or 20x this kind of money for electronics?

I recall when the NAD 3020 marked the beginning ( 1978ish ) of an exciting Audiophile world, is this M33 guiding us safely/pleasantly/joyfully into the 21st Century? I wish it was made in Toronto. ( or Valencia, Ca. )

Thank you for another adventure , your writing never seems like a 'paint by numbers' review as is so common today.

Tony in Venice

Kal Rubinson's picture

Regarding Roon:

I have heard reports that the M33 does not support Roon and that I must have reviewed a "special" version not available to the public. I do not believe that is true.

The time I had the M33 was prior to 9/21. It was on that date that Roon cut off working with non-certified devices although Roon asserts that those already registered in use will have continued support. Only new ones will not be recognized until the device is certified. See:

When I learned of this change, I asked NAD about support for the M33 and the response they sent is as follows: "
“As Roon explain themselves, any device that has been used prior to Sep 21st, even in an uncertified way, will continue to work. The NAD M33 is with Roon for final certification approval and both companies are working together to have this completed as soon as possible.”

I did note, in the review, that the M33 was not yet certified but that it worked. That is true and, I believe, true for all M33s put into Roon use prior to 9/21. However, any newly purchased M33, although identical in all ways to the one I had, is likely to be ignored by Roon if the user attempts to register it with Roon after 9/21 and before Roon/NAD work out the certification.

I hope that this makes the current situation clear and that the certification issues will be completed soon.

MikeP's picture
sonictomb's picture

Thanks for this review, Kal.

I'm really loving the idea of this amp and minimizing my setup, but I'm also into vinyl.

Did you experience any vinyl using the digitized RCA inputs?

That would be the crux for me pulling the trigger on this, as I love all the convenience it offers for digital but I need a competent phono stage as well.

Wildcoach's picture


Enjoyed your review even though I didn't quite understand all of the test results (all? Hardly! But a few, hopefully, LOL).

In reading page 2 where you discuss the amplifier component of the M33, and the testing page, I was hoping you could comment on the M33's ability to dirve low loads. I have a pair of Infinity Kappa 8's which present very low (1.3) and varying loads throughout the range.

How does this new-style class-D amplifier section handle low loads like that? Is it stable or should I just stay clear of it and buy a McIntosh?



Just FYI, the M33 is now considered (officially) Roon Ready and Roon Tested:

I did it with my M33 recently... no problems whatsoever.