Hardware Reviews

Naim NSS 333, NAC 332 & NAP 350: the dream team

Naim NSS 333 streamer, NAC 332 preamplifier, NAP 350 power amplifiers review https://the-ear.net

Naim NSS 333 streamer, NAC 332 preamplifier, NAP 350 power amplifiers

Apparently the NAC 332 is the first Naim preamplifier to have an onboard power supply. In a day and age when finding any preamplifier without its own power supply is unlikely this is hardly shocking but it’s clearly a change of approach for Salisbury’s finest audio mongers. It has been a while since the original Classic range whence the last dedicated preamplifier was forged, and in that time Naim’s head of engineering Roy George has handed his responsibilities over to Steve Sells, the man behind the mighty Statement. So the New Classic range of which the 300 series is the flagship is a new Naim in more ways than one, not least it’s a more compact range where there the confusion of options has been narrowed down to something more navigable for the Naim newcomer.

These models still sport some of the connectivity for which this brand has been renowned, specifically DIN in- and outputs but the signal no longer goes through a power supply on its way to the power amp as was formerly the case. New Classic goes together in rather more typical audio fashion with only a few idiosyncrasies for the irregular user to get his or her head around.

Naim NSS 333 streamer, NAC 332 preamplifier, NAP 350 power amplifiers review https://the-ear.net

The 300 series was launched at Munich in May 2023 but took a while to get to me because, one suspects, Naim’s marketing department was charged with promoting its more mainstream Uniti and Mu-So offerings, leaving the ‘proper’ hi-fi to fend for itself. But it has been worth the wait and I have been having trouble turning these components off in order to concentrate on more pressing deadlines.

The source in the range is the NSS 333 streamer which is effectively only one tier down from Naim’s flagship the ND 555, the latter has a separate power supply, the newcomer has the option of adding an NPX 300 to augment the onboard PSU. The NSS 333 offers digital inputs but limits these to SPDIF variants, so no USB, and even has a couple of digital outputs albeit what they are for is hard to say, there is no standalone DAC in the range. Analogue connections extend to XLR, RCA and DIN while network connection is via ethernet or wi-fi (with antennas in the heatsink). The remaining multipin sockets are for connections to an NPX 300 power supply and are capped when the onboard supply is in use. Like all New Classic components the power inlet is a loose fit in the casework in order to minimise vibration transmission by the mains cable, a cable which is supplied with a 13A plug that has a similar anti resonance system on its outlet. Naim clearly take the effects of vibration on electronics seriously.

Naim NSS 333 streamer, NAC 332 preamplifier, NAP 350 power amplifiers review https://the-ear.net
Naim NSS 333

Under the hood the NSS 333 has Naim’s NP800 streaming engine which runs on balanced connections to keep noise down and works with a broad range of services including Spotify Connect, Apple Music, Chromecast and Airplay 2 alongside the more familiar options. It runs two master clocks in order to accommodate the 44.1kHz and 48kHz base sample rates for PCM and runs integer oversampling prior to D/A conversion using the core of a PCM1791A chip.

The output stage is Naim’s preferred balanced impedance type but they prefer the DIN route for normal cable lengths, listening via this connection does rather back up this preference too. Playback control is via the Focal & Naim app which effectively controls the NAC 332 when both units are used together, the clever bit here being Zigbee which is a wireless connection between streamer and preamp that allows the two to work in unison, even to the extent that the streamer will display volume level numerically. You can control volume with the app or handset on the NSS 333 but if you’re after decent sound quality this is discouraged in favour of a dedicated preamplifier with a serious volume system like that found on the NAC 332. This has a reed relay based switched resistor attenuator very much like that found in the Statement NAC S1 preamp, it’s designed to offer a constant frequency response and can be controlled with the super smooth knob or the Focal & Naim app.

Naim NSS 333 streamer, NAC 332 preamplifier, NAP 350 power amplifiers review https://the-ear.net
Naim NAC 332

The inputs on the NAC 332 are mappable in true Naim style, any of the XLR, RCA or DIN sockets can be linked to one of the buttons on the front and which are mirrored on the remote. Not quite any actually, the Zigbee system means that if you don’t map the streamer to the streamer button the app can’t control it, but that’s fair enough. Assigning inputs is slightly arcane and involves counting pairs of marks on the volume encoder to establish which of the eight inputs you want to assign to which button. But this is pretty straightforward once you get your head around it.

If you want to have the NAC 332 tell the NAP 350 power amps to turn on and off it’s necessary to connect the optical cables supplied. If on the other hand you want to listen to headphones there is a socket right there on the front panel, which is I believe another first for a Naim preamp. The NAP 350s are the first Naim monoblock power amps since the venerable NAP135s (70W), they follow the same peculiar power indication in the name, the NAP 350 is a 175 Watt amplifier (it will however deliver 345W into four Ohms at 1% distortion). And this makes it a veritable beast by Naim standards where only the Statement offers more power, the NAP 500 stereo amp is a 140W design.

Naim NSS 333 streamer, NAC 332 preamplifier, NAP 350 power amplifiers review https://the-ear.net
Naim NAP 350

The NAP 350 has separate DR (discrete regulator) power supplies for both input and gain stages, eight NA009 Statement style output transistors and a new constant current source gain stage. It has a seven speed fan on the back that was apparently “tested using compressed electronic music from Major Lazer at full volume on loop; this amplifier is party proof.” It would probably take something like that to kick it off, while I do have some Major Lazer in the library I didn’t manage to push it hard enough to provoke any action from the fan.

Inputs on this monoblock are limited to XLR for Naim’s balanced impedance connection to the preamplifier, this is not the same as a balanced connection in the conventional sense as it’s effectively single ended with shielding, but you can connect a balanced output from a non Naim preamplifier. The speaker cable terminals accept 4mm banana plugs only, another Salisbury peccadillo selected for sound quality reasons of course; less metal generally means better sound. The only bugbear I have with these amps, and to a marginally lesser extent the rest of Naim’s Classic models, is that there is not enough space under the sharp cooling fins for fingers. These are not particularly heavy amps (16.5kg), but putting them down is a painful experience for all but the steel fingered.

Sound quality

Unlike Naim amplifiers of yore the NAP 350 does not depend on low capacitance/high impedance cables for stability so you can use pretty well any speaker cable, including Townshend Fractal F1 which is the complete opposite of NAC A4 in electrical terms; high capacitance/low impedance. I tried these amps with a variety of loudspeakers including B&W 802 D3s, Dali Epikore 11s, Vivid S12s, PMC twenty5.26is and even ATC SCM40A actives, the latter using just the NAC 332 and NSS 333 of course. On each occasion the character of the loudspeakers was more obvious than the electronics, the 300 series still has that slightly dark sound associated with Naim but the more you listen to it the more it seems that this balance is a result of clean highs rather than any form of rolling off.

Naim NSS 333 streamer, NAC 332 preamplifier, NAP 350 power amplifiers review https://the-ear.net

I also discovered that for best results you should stick with the DIN connection between source and preamplifier, even compared to Atlas Arran Ultra Grun RCA interconnects, which are the most revealing cables I’ve tried in recent years the Naim cable supplied in the box has the upper hand because of that DIN connection. The difference is ridiculous in terms of timing, the sound goes from engaging and revealing to impossible to tear yourself away from when the DIN connection is used. It’s enough to warrant a campaign to bring back this undervalued connection on more audio equipment, as far as I know DNM is the only other brand that uses it and their products are pretty thin on the ground these days.

Essentially if you want to get the best out of probably any source and preamp pairing from Naim DIN is the way to go, this limits the choice of cables of course but sometimes that can help. I also used the XLR terminated interconnects supplied to connect NAC 332 to the NAP 350s for the most part albeit I did experiment with Townshend Fractal here and this didn’t hurt the results.

Naim electronics have always been very good at timing and the 300 series system is no exception, where it differs to other models in the range is in the quietness of backgrounds and the quantity of information that this reveals. All the efforts to keep vibration and electrical noise at bay means that there is far less in terms of mechanical disturbance and high frequency electrical grunge than in the earlier Classic models. The deal used to be that you could have engagement and all the physical and emotional impact that that entails but without the transparency found in other high end gear, Naim have now managed to combine both qualities and the results are gobsmackingly good. If there is a beat in the music it’s hard to sit still but you can also hear the quieter sounds that combine to give each performance a depth and naturalness that makes it realistic.

Naim NSS 333 streamer, NAC 332 preamplifier, NAP 350 power amplifiers review https://the-ear.net


Adding the NPX 300 to the NAC 332 was not a subtle experience, even with some fairly straightforward acoustic guitar and double bass from Baden Powell and Eberhard Weber (Solitude on Guitar), the change was dramatic. Everything became more three dimensional and relaxed, the musical coherence seems to increase because of a further quietening of the background and the music became richer and more natural. On a more lively track (Outkast – Love Hater) I was prompted to pick up the air drumsticks, and that doesn’t happen very often.

With the NSS 333 streamer, adding an NPX 300 increased power in the bass to quite a powerful degree. It might have been the nature of the music played or the fact that the active ATCs were in action at the time but there was a distinct increase in weight and shape to the bottom end, and a very gratifying one too. Dynamics also improved markedly and timing stepped up a notch from excellent to spectacular. It was at least as big a jump in performance as achieved with the NAC 332 and so significant that those who hear it will be hard pressed to sleep until they have an NPX 300 on the back of their streamer.

Naim NSS 333 streamer, NAC 332 preamplifier, NAP 350 power amplifiers review https://the-ear.net

The really appealing thing about the NAP 350s is that they do bass properly. Naim have long held that you don’t need loads of power to get good bass, preferring the nimbleness of less well extended low end to the slowness that delving down too deep can bring. That changed with Statement and its one horsepower (764W), and has trickled down to the 300 series to a thrilling degree. 175W is a lot for a Naim, a brand for which 90W was considered adequate for several decades, and they know what to do with it in order to maintain the reference level timing that the company has always traded on. With a big speaker like the Dali or B&W things get positively prodigious, put on a good live recording and you can feel the venue. The mids and highs might give a strong sense of its acoustic character but you don’t get the full effect if the bass doesn’t go all the way down and move with the speed of the rest of the frequency band. This quality balances the sound in a way that older Naim amps and many competitors cannot, it means that when John McLaughlin, Jan Hammer, Billy Cobham et al let rip on Birds of Fire (Mahavishnu Orchestra) you get the full ferocity of their playing without it screaming at you, because the bass is there to balance the mid and high frequency action. It acts like an anchor and keeps all the instruments grounded, they still fly high but remain coherent and in synch with one another.


Naim have done a remarkable job at trickling down what they learnt from Statement into the 300 series, these components are in another league to both the original Classics and the 200 series models. The prices are higher than used to be the case but so is the sound, build and feature quality, the 300 series deserves to put Naim back at the top of the tree for those looking to get not only the best sound and functionality for their money but also a degree of connection to the performance that few alternatives can match. There is something so unerringly right about the way that the 300 series components present the music, and this makes it more involving and engaging than a lot of high end gear. It’s something that Rega achieves with its turntables but very few can do with digital, ultimately it’s what listening to music is all about. Communication is critical and this system does it better than most.


NSS 333
Type: network streamer and DAC
Distortion THD: 0.002% @0dBFS, 1kHz
Signal to noise: Digital: 108dB ref 0dBFS A-wtd, volume at 0dB
Streaming Inputs: ethernet, wi-fi
Native streaming services: Qobuz, Tidal/Tidal Connect, Spotify Connect, internet radio,
Wi-fi inputs: Airplay 2, Bluetooth aptX
Digital inputs: 2x coaxial (BNC, RCA), 2x toslink optical
Digital outputs: coaxial BNC
Analogue outputs: RCA, XLR, 5-pin DIN
Supported file formats: AAC, ALAC, M4A, DFF, DSF, FLAC, MP3, WAV, Ogg, DSD
Supported digital formats: PCM up to 384kHz in 32Bit, DSD up to DSD128
Headphone output: N/A
Control software: Focal & Naim app, UPnP, RoonReady
Dimensions HxWxD: 91.5 x 432 x 317.5mm
Weight: 11kg
Warranty: 2 years

NAC 332
Type: transistor stereo preamplifier
Analogue inputs: 3x RCA, 2x XLR, 2x 5-pin DIN, 1x 8-pin DIN
Analogue outputs: pre-out RCA & XLR
Headphone output: 6.35mm headphone jack (1.5W into 16 Ohms)
Distortion THD: 0.003% @2.2V input volume at 0dB, 1kHz
Output impedance: not specified
Output voltage: 10Vrms max
Dimensions (HxWxD): 91.5 x 432 x 317.5mm
Weight: 11kg
Warranty: 2 years

NAP 350
Type: mono power amplifier.
Analogue input: XLR
Analogue outputs: 4mm sockets
Power output: 175 Watts 8Ω @0.1% THD+N (195W @1%), 345 Watts 4Ω @1% THD+N
Frequency response: -3dB @ 1.4Hz to 100kHz
Gain: +29dB
Distortion: THD+N 0.006%
Signal to noise ratio: not specified
Dimensions (HxWxD): 91.5 x 432 x 317.5mm
Shipping weight: 16.5kg
Warranty: 2 years

Price when tested:
NSS 333 £8,500
NAC 332 £8,500
NAP 350 £13,000 pair
NPX 300 £5,900
Manufacturer Details:

Naim Audio
T +44 (0) 1722 426 600


streamer, preamplifier, power amplifier, power supply


Jason Kennedy

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