NAD M33 streaming DAC amplifier - HiFi Review

My first integrated amplifier was the popular NAD 3020e variant of the hugely successful original 3020 that launched in the late seventies. The design had been refined a little by the time the ‘e’ iteration arrived with a more elegant-looking front panel equipped with push button source select for four inputs, plus rotary controls for bass, treble and balance. I loved it! While all my pals lauded over their graphic equalisers, I was happy knowing that my source was unsullied by the kind of electronic noise that routing an audio signal through additional circuits can generate. I had so few buttons to play with, apart from a mono selector and a low-level switch for listening to low volumes, I was confident that I was listening to the purest audio signal possible. Technology and the way we listen has moved on massively since then of course and is neatly demonstrated by NAD’s latest generation of the integrated amplifier and this HiFi review of the M33 streaming DAC amplifier.

At around £4,000, the M33 just-add-speakers music solution is a considerable outlay. But what you get is a substantial package that has just about everything for networked music streaming and multi-room connectivity at home. There’s even digital room correction software built-in (a modern day graphic equaliser) and headphone and turntable compatibility are not forgotten in this remarkably technological box of tricks.

Design

The NAD M33 streaming DAC amplifier claims 2x 200W (into 8ohm) of Class D amplification and uses an Eigentakt (meaning self-clocking) module built by the Danish company Purifi. It has the latest 32-bit/384kHz ESS Sabre DAC and Dirac digital room correction software is built in, too. The NAD M33 has an eye-catching 7in colour TFT touchscreen display and is one of the best I’ve seen for communicating album artwork, track info, menu navigation and system settings. Equipped with its parent company’s BluOS operating software with multi-room connectivity, the M33 has the best streaming platform I have come across, particularly the desktop version.

At the back of the NAD M33 there are two MDC slots for future hardware expansion. This could be a new DAC chipset hardware upgrade in the future, for example, or other technologies not yet thought of. The M33 has wireless control with AirPlay 2 and aptX HD Bluetooth (two-way) integration. There is a comprehensive array of digital and analogue connectivity including HDMI with ARC for those wanting to hook up a TV to the M33. Finally, there is a built-in moving-magnet (MM) or Moving Coil (MC) phono stage for a turntable and a 6.35mm headphone jack.

Quality

The M33 is an attractive piece of equipment with a clean front panel and an array of vents on the top of the chassis – described as a ‘six-pack’ by my teenage daughter – to facilitate internal operational cooling. Overall, the M33 looks rather understated considering its complexity and power output claims. The non-magnetic aluminium construction is designed to dissipate the heat generated within and an intriguing set of temperature readings for different parts of the chassis can be found in the settings menu. The M33 is set on iso-point feet to isolate it from external vibration, the base cups are provided.

Performance

Setup

I have the NAD M33 streaming DAC amplifier wired to my KEF R700s floorstanding loudspeakers via a pair of Atlas Hyper Bi-wire Achromatic speaker cables I reviewed recently. The system is set up in our living space and everyone in the household has been interacting with it remarkably seamlessly. The NAD has taken over from the Naim Uniti Star, our usual go-to one-box home music system.

Dirac room correction

I have had a good play with Dirac digital room correction, which is very suited to the varied listening positions that prevail in a general living space. In action, it has made a subtle change with a little gain in the low frequency, but I would not say that it’s been a revelatory experience. The tuning of the Dirac was simple following a download of the app to my smartphone and 15 minutes of annoying the dog with weird low and high frequency bursts as I placed the supplied mic that plugs into the USB port at the back of the M33 in different positions. There is a bit of choice when it comes to tuning the room. On my phone, I had just one filter, but I believe you can purchase other library options. I was asked to adjust the algorithm from that suggested to my taste. My Dirac algorithm was only tuned between 0 to 500Hz, hence the low frequency adjustment I noticed, but you can buy wider filters.

The M33 is an all-digital design and enables the Dirac software to tailor the output of any source exactly to your liking and listening position for optimum performance in your space. Even analogue signals from a turntable are digitised after the phono stage input, but this can be bypassed.

General Performance and Bluetooth

Overall, the M33 is a terrific performer. Wi-fi connectivity has been faultless, while Bluetooth – given a full work out with the kids regularly swapping devices in and out – has been reliable and consistent and the sound quality certainly matches up to the Naim Uniti Star’s performance that is usually in situ in our living space. It lacks a CD player and SD card slot found on the Naim, but it’s a superstar in terms of streaming flexibility and has the handling capability to drive my KEF speakers with ease.

Critical listening

To be a little more analytical about things, I recalibrated the Dirac software to a focussed, single listening position. The soundstage from the NAD M33 is nicely delivered and has a pleasingly wide feel to it. Vocals are dead centre in the soundstage and sound slightly laid back tonally. Higher quality recordings come into their own, such is the DAC chip quality. There is fine energy from this all-in-one system that puts it amongst the best I have heard. Playing the Chromatics’ Sound of Silence and a 24-bit version of Better from Zayn’s new album Nobody is Listening, both tracks have fine production and are fizzing with energy and bounce when played on the NAD.

The NAD delivers plenty of detail to the speakers with the right tracks, for example, Tin Pan Alley, Stevie Ray Vaughan’s wonderfully constructed (and recorded) song, not to mention the Jamie Cullum observation below.

I have just realised that I have not used the remote at all. I have been controlling streaming, volume, settings, libraries, etc. on the outstanding BluOS app, either on my Pixel smartphone or iPad.

Headphones

Using Oppo’s PM-2 planar magnetic headphones upgraded with Atlas’ Zeno headphone cable for a bit of personal listening, the NAD’s headphone output is really impressive. The PM-2s required a bit more drive than I expected, but the M33’s protection circuitry is clever enough to mute the speaker output should anyone accidentally yank the headphone jack from the front panel socket.

The Focal for Bentley Radiance headphones that I reviewed recently gave the better performance. They are easier to drive and the M33 delivers a fantastically revealing level of detail with Jamie Cullum’s rasping vocal in Gran Torino sounding terrific with the extra resolution.

Networked storage

BluOS seamlessly accesses my collection of 24-bit and other recordings from my networked audio server. However, I did notice that DSD recordings are not processed and the one DSD file I have would not play at all. This is no great loss for me.

Overall

The NAD M33 is one of the best all-in-one streaming DAC amplifier solutions around

The NAD M33 is one of the best all-in-one streaming DAC amplifier solutions around, easily. The BluOS multi-room music software is simply a joy to use and seamlessly allows you to get on with listening to your favourite music no matter what the source. I am a strong advocate of Bluesound’s more compact Powernode 2i streaming DAC amplifier – also owned by the same Canadian parent company – but the NAD M33 brings greater audiophile credentials, bags of style, flawless functionality and seamless BluOS integration and will deliver universal music playback for years to come.

Specification

From the site:

Rated output power (ref. 20Hz-20kHz at rated THD, both channels driven) >200 W into 8 ohms >380W into 4 ohms
Rated output power, Bridge mode (ref. 20 Hz – 20 kHz at rated THD)>700 W into 8 ohms
Input sensitivity865 mV (ref. 200W 8 ohms, Volume maximum)
THD (20 Hz – 20 kHz)<0.003 % (1W to 200 W, 8 ohms and 4 ohms) Signal-to-Noise ratio>98 dB (A-weighted, ref. 1 W out in 8 ohms) >120 dB (A-weighted, ref. 200 W out in 8 ohms)
Clipping power>210 W (0.1 % THD 1 kHz 8 ohms)
IHF dynamic power – 8 ohms: 260 W 4 ohms: 520 W
Peak output current ≥25 A (in 1 ohm, 1 ms)
Damping factor >800 (ref. 8 ohms, 20 Hz to 6.5 kHz)
Frequency response ±0.2 dB (20 Hz -20 kHz) -3 dB at 60 kHz

Preamplifier

Line in

Input Impedance (r and c)47kΩ/180pF
Input Sensitivity 280mV (ref. 500mV out, Volume Maximum)
Maximum input level 20Hz-20Khz2 Vrms/8 Vrms (low sensitivity mode)
Tone Controls – Treble: ±10dB at 10kHz Bass: ±10dB at 100HzMax Output Signal4Vrms (ref. 0.1% THD)

Preout

Maximum output level 3.9 Vrms (ref. 0.1% THD)
Signal-to-Noise ratio >120 dB (A-weighted, ref. 2 V out)
Output impedance 100 ohms

Sub out

Maximum output level 1.1 Vrms (ref. 0.1 % THD 100Hz)
Signal-to-Noise ratio >102 dB (20 Hz-20 kHz, ref. 1V out)
THD+N <0.005 % (refer 1.1 V 20 Hz-200 Hz)
Output impedance 680 ohms

Phono

Input sensitivity MM: 1.2 mV
MC: 100 µVInput impedance (R and C)MM: 56 kohms/100 pF
MC: 100 ohms/280 pFSignal to noise ratio (ref. 2 V Preout A-weighted)MM: >92 dB
MC: >76 dBTHD+N (ref 2V Preout 1kHz)MM: <0.003 %
MC: <0.02 %RIAA response accuracy MM/MC±0.2 dB 20 Hz -20 kHz

Headphones

Output Impedance 2.2ohms
Output power >100 mW/32 ohms

BluOS

Supported audio file format* MP3, AAC, WMA, OGG, WMA-L, ALAC, OPUS
Supported high- resolution audio file format* FLAC, MQA, WAV, AIFF
Sampling rate up to 192 kHz
Bit depths 16 – 24

Connectivity

Network connectivity Gigabit Ethernet RJ45
Wi-Fi 5
Supported network file share protocol Server Message Block (SMB)
USB1 x Type-A port for connection to USB memory stick (FAT32 or NTFS formatted) and supported peripherals
Bluetooth quality aptX HD 5.0
Bluetooth connectivity Two-Way (Receive and Headphone modes)

User Interface

Supported operating system** Music playback from network shares on the following desktop operating systems: Microsoft Windows XP, 2000, Vista, 7, 8 to current Windows Operating Systems and macOS versions**
Mobile Application Free BluOS Controller App available for download from the respective App stores of Apple iOS devices (iPad, iPhone and iPod), Android devices, Kindle Fire and Windows or macOS desktops
Front panel – 7-inch full colour touch screen
Remote control HTRM 2 remote control
For supported music service and partners please see bluos.net

Power Consumption

Auto Standby ON <0.5W
Idle Power <40W

Dimensions and weight

Dimensions WxHxD ** 435 x 133 x 396 mm (17 1/8 x 5 1/4 x 15 5/8”)
Net Weight 9.7kg (21.4lb)
Shipping Weight 18.4kg (40.6 lb)

Notes

* – Supported audio file format, cloud services and free internet radio are subject to change without notice.
** – Gross dimension includes feet and extended rear panel terminals