September 2024

World Premiere Review!
Naim Audio NAP 350 Reference Mono Amplifier
And NVC TT Phono Stage With NPX TT PS Review
The Naim analog system sounded like listening to the master tape.
Review By Tom Lyle

   In the early 1990s, I often visited one of the local high-end audio salons near my home. During one of these visits, while my friend and I were bothering the staff with silly questions, I asked a salesperson which CD player or turntable was playing the loud, awesome-sounding music in the background. Their answer? A Naim Audio FM tuner. To say that I was impressed (and embarrassed) is an understatement. This was my first experience, my first experience with Naim.

After this experience, my audiophile friend and I started believing that Naim had a mystic aura surrounding them. In those pre-internet days, rumor had it that this audio company was run by nonconformists, at least compared to the other "major" audio companies we were familiar with.

UK-Based
Eventually, I learned more about the UK-based Naim. Finally, about two months ago, I received my first Naim components for review, which included a pair of Naim Audio NAP 350 Reference monoblock power amplifiers, a Naim NVC TT phono stage, and its accompanying NPX TT power supply.

Naim (pronounced "name") is a high-end audio manufacturer that was founded in 1973. It is based in Salisbury, England, which Google Maps describes as "A medieval cathedral city in the southern English county of Wiltshire. Salisbury is nine miles south of the iconic prehistoric stone circle at Stonehenge, which stands on the grassland of Salisbury Plain."

Naim stresses that its components work synergistically with other Naim Audio products. This includes Naim cables, so much so that a pair of Naim interconnects were included with the NAP 350 monoblocks and the NVC TT phono stage. These components are part of Naim's "New Classic" 300 Series. I was disappointed that I wasn't also sent Naim's NAC 332 preamplifier. Still, since I assume that not all of their customers will purchase a complete Naim Audio system, my findings in this review will remain valid.

NAP 350 Reference Monoblocks
Naim describes their NAP 350 Reference monoblock power amplifiers as a "state-of-the-art" 175-Watt monoblock design that "offers tailored capability across a large range of loudspeaker options." They tout the amp's high-current delivery, which is one of the reasons why I agreed to review these amplifiers. This is because my reference Sound Lab electrostatic speakers are a rather challenging load, as I usually argue that they need at least 250 Wpc to sound their best. The exception to this "rule" is when powering them with an amplifier with enough current to ignore that these speakers' impedance drops relatively low when listening to music at a realistic volume. Although the Naim NAP Reference monoblocks' output is "only" 175 Watts, they peak at a massive 1.7kW into low impedances and thus can drive "even the most demanding loudspeakers."

The NAP 350 uses a new high-current output stage that benefits from a matched pair of Statement NA009 custom power transistors. Combined with their "acclaimed DR technology, it guarantees a stable and low-noise power supply."

Handsome
I thought that the relatively compact black rectangular cabinets of the Naim Audio NAP 350 monoblocks were very handsome looking. Their polished black accents with "thermally conductive aluminium alloy" heatsinks on their sides and the illuminated Naim logo on their front panel made these monoblocks look "high-tech" but far from ostentatious. The Naim NAP 350 monoblocks are compact. Although they have a typically standard component width of 17", they are only a few inches high and a bit more than one foot deep. They weigh a significant 36.4 pounds each.

Front
On the front of each Naim Audio NAP 350 monoblock, there is only a power/standby switch on its far right side. After the amps are connected to the AC, they remain in standby mode; pressing this switch powers the amp and illuminates the centrally located Naim logo, indicating they are ready to play music. A switch on the rear panel next to the amp's IEC AC cable input lets one choose between "instant on" or "auto standby." Choosing "instant on" keeps the amp's sensitive audio circuits permanently powered. Naim says that this results in the best sound quality when listening to one's first musical selection of the day. A balanced XLR input is on the rear panel next to this standby switch.

The Naim NAP 350 only accepts interconnects terminated with an XLR. The amp's speaker inputs are unique. I was told that the custom Naim loudspeaker connectors work best with either Naim NAC A5 or Super Lumina speaker cables. Since I was not supplied with either, I used banana plug adapters on my reference Kimber Cabon 18 XL speaker cables terminated with spades.

Also on the NAP 350's rear panel is a brightness/reset button, a USB input to accept upgrades, an input for a remote cable that can be connected to other Naim components, and what Naim calls an 8-step intelligent fan control. This fan didn't make any noise I could detect, even with no music playing. I only realized these monoblocks had a fan when I read their manual.

Connected
I connected the Naim Audio NAP 350 monoblocks' power cables directly to the custom AC wall outlet receptacles when auditioning these monoblocks in the evening. My listening room has two separate 20-ampere power lines running directly to the circuit box in our basement. During daylight hours, our local electric company's AC is so polluted, it results in inferior sound quality coming through my speakers. Power conditioners improve this inferior sound quality to some extent, but their full potential is only realized when I use battery power supplies. I use a separate battery power supply for the power amplifiers and another for the rest of the system. The Goal Zero battery power supplies are similar, but upgraded since I reviewed the Goal Zero Yeti 400 Lithium Portable Power Station back in January 2019. It was a much simpler and superior experience when I auditioned for the Stromtank S2500 battery power supply I reviewed in the February 2018 issue. But I digress.

Setting up the Naim NAP 350s was easy; I connected the speaker cables, and the interconnects that ran to either my reference Nagra Classic Preamp or two-chassis Pass Laboratories XP-22 linestage, powered the amps, and started listening to music.

Naim Audio NVC TT Reference MM/MC Phono Stage
With NPX TT Power Supply
The Naim NVC TT Reference MM/MC phono stage was developed from Naim's Solstice Special Edition phono stage and power supply pairing. Although the NVC TT Reference phono stage can also be powered using Naim's NSC 222 or NAC 332, I was sent the NPX TT, Naim's NVC TT specific power supply.

Both the phono stage and its power supply are compact, half-sized components. The phono stage and its power supply's exterior are similar to the NAP 350 Reference monoblock amplifiers. Like the monoblocks, the front panel of the phono stage and its power supply have an illuminated Naim logo on their front panel when powered.

On the rear panel of the phono stage are switches that let the user choose from 16 resistance settings and 16 capacitance settings. These settings enable this phono stage to work with just about any Moving Coil (MC) or Moving Magnet (MM) phono cartridge on the market.

Connects
The phono stage connects to the Naim Audio NPX TT Power Supply with a supplied umbilical. On the rear panel of the NVC TT Reference MM/MC phono stage (which I will often call the NVC TT phono stage from this point forward), there are separate inputs for Moving Magnet (MM) and Moving Coil (MC) phono cartridges. Next to the MC input, there is a switch for one to choose between high (67 dB) or low (61 dB) level output, and to the left of these, there is a small dial to select its 16 selectable resistive values from 1000 Ohms to 85 Ohms. Next is another small dial for capacitive values, from 100pF to 4600pF.

Outputs
Oddly, even though the inputs on the Naim 350 NAP monoblocks have only balanced XLR, the outputs for their NVC TT Reference phono stage are either unbalanced RCA or 5-pin DIN. If one uses a Naim preamplifier, the NVC TT phono stage can connect to it using the provided 5-pin DIN connector. The Pass Labs and Nagra line stages I used for this review do not have DIN inputs, so I used the RCA outputs of the Naim phono stage for this review using Crystal Cable's Micro Diamond 2 interconnects.

Like the NAP 350 monoblocks, setting up and connecting the Naim phono stage was simple. I placed the phono stage and its power supply on the same hanging shelf of my Arcici equipment rack, separated only by an inch or so. Despite being relatively close to each other, the output of this phono stage had a pitch-black background, even when no record was playing. Throughout the review period, I didn't hear a hint of radio or electronic interference or any other noise, even if I pressed my ear against the speakers' grille.

Analog
The analog front end of the review system included my reference Basis Audio model V turntable, perched on the 50-pound stainless steel top plate supported by three adjustable inner tubes of the Arcici equipment rack. A low-output moving coil Top Wing Suzaku, "Red Sparrow" phono cartridge with an output of 0.2 mV, was mounted on a Tri-Planar 6 tonearm. The tonearm's integral interconnect terminated with RCAs was connected to the inputs of the Naim NVC TT phono stage. 

The Naim Audio NVC TT phono stage was a very user-friendly component, primarily because of how it powered and shut down. After all, it is a phono stage – once it is set up, there isn't much one needs to do. There is no power switch; this phono stage powers up once connected. However, it goes into sleep mode after 20 minutes if it doesn't receive a signal. In this sleep mode, which Naim calls "auto standby," the phono stage and its power supply consume less than 0.5W of power. This "instant on" feature sets the phono stage into a mode that permanently powers the audio circuitry, ensuring that one hears this phono stage at its best.

It is possible to power the Naim NVC TT phono stage without the Naim NPX TT power supply. Still, one would be correct if one imagined the sonic benefits an external power supply would provide. Adding the NPX TT to the phono stage removes the load from the NSC 222 or NAC 332 power supply and gives the phono stage a dedicated and isolated supply.

Sound Of The Naim Audio NVC TT Phono Stage With NPX TT Power Supply
The Naim NAP 350 Reference monoblocks, the NVC TT phono stage, and the NPX TT power supply have similar sonic characteristics. Both components have inky black backgrounds, allowing one to hear even the most obscured musical details.

But this phono stage, like Naim's NAP 350 monoblocks, is a mighty beast, bringing to mind the cliche "an iron hand in a velvet glove." Every record I played that contained many low frequencies demonstrated this phono stage's seemingly infinite bass response.

It wasn't just that there was "lots" of bass; it was a bass that was as good as any phono stage I've heard anywhere near its price range.  Musicality might not be the first thing one thinks of when describing bass, and of course, the other frequencies that are occurring simultaneously affected my perception of the sound of this Naim phono stage setup. Traits such as its excellent transient response and tight-sounding upper and mid-bass frequencies made instruments and sounds with a good amount of bass energy sound exceptional because of this.

In addition to the muscular sound of the NVC TT / NPX TT combo's bass, its handling of even the most delicate-sounding voices and instruments was also rendered with a highly musical sound, favoring realism above all else.

The dynamic range of the Naim Audio  NVC TT / NPX TT combo was outstanding. The micro- and macro-dynamics were reproduced as realistically as I could have hoped. This enabled me to hear every detail of the music, without ever sounding "etched". Conversely, more than once I practically fell off my listening seat during an explosive crescendo, concert bass drum hit, or a band's heavy metal explosion.

I was convinced this phono stage had a soundstage that mimicked the recorded event. I'm not privy to the design parameters or mathematics of how a recording's soundstage is reproduced, although in the studio I've taken a signal out of phase to make it sound as if it is floating in space. But I doubt very much that an out-of-phase signal is introduced anywhere in the phono stages circuitry. Regardless, whether the soundstage I heard when using the Naim NVC TT / NPX TT setup was reproducing an actual event or one manufactured by a crafty studio engineer, it was awfully impressive/ When listening to a recording that was made within a "real" space it seemed as if it was drawn to scale, or if it was a studio recording that placed the instruments in certain areas of the soundstage, this hardly mattered. This soundstage depended on what was on the recording and its sound quality more than anything else, which is what one should hope a high-end audio phono stage was capable of.

Album
I'm lucky  – I scored two different vinyl copies of Kraftwerk's album The Mix in my collection – their album from 1991 with rerecorded versions of their catalog's highlights. One version has the vocals sung in English, the other in German. Hearing the first track, "The Robots," on vinyl was a thrill when listening to it through the Naim phono stage setup and especially when paired with Naim's NAP 350 monoblocks in the system. The dual bass lines that entered a few minutes into this track were rendered with as much detail and sonic punch as when listening to the CD rip. These two bass lines were separated in space, and at the same time were as powerful sounding as I've ever heard them, the lowest frequencies shaking my gut as well as the window frames in my listening room.

Although I played this album more as a test of the system's bass response and how I should set the dual SVS SB16-Ultra subwoofers to support the sound of the Sound Lab electrostatic Sound Lab Majestic 545 speakers than anything else, the Naim phono stage produced these bass lines on the "The Robots" as powerfully as I've ever heard them. The deep bass shook my gut as well as the window frames in my listening room.

Versions
Later in the Naim Audio NAP 350 Reference Mono amp and NVC TT Phonostage with NPX TT power supply review period, I enjoyed two versions of Prokofiev's soundtrack to the Soviet film Alexander Nevsky. The first was a CD rip of Yuri Termirkanov conducting the St. Petersburg Philharmonic, which I will discuss when I reveal what I heard when auditioning for the NAP 350 monoblocks. But my favorite version of Alexander Nevsky was my cherished first pressing of the RCA "Living Stereo" vinyl of Fritz Reiner conducting the Chicago Symphony Orchestra that was pressed in 1960 and in astonishingly good condition for a 64-year-old record!

I hope that one day someone will give me a convincing explanation as to why a high-quality phono cartridge and phono stage can suppress surface noise. Somehow, this equipment "knows" what music is and is not. My guess is that a good phono cartridge "digs" deeper into the grooves of a record, but I have a feeling there's more to it than that. This vintage RCA LP's surface noise is completely silent because there is some slight noise, but it is only noticeable when passing when there is no music, such as when I first put the needle on the record and between movements of this score.

I had a blast listening to this often-bombastic sounding score, a typical Prokofiev barn-burner, but it had many very introspective moments, too. Throughout the entire LP, the music was so convincing sounding I could imagine myself standing on the podium alongside Maestro Reiner. The feeling of entering a sonic time machine was never more significant, thanks to this Naim phono stage / power supply.

The Naim Audio phono stage / power supply combo transferred the music signals of the thrilling "Battle On The Ice" sequence that starts side two to my linestage, and eventually to the speakers as if I were there, not listening to the master tape of this recording but sitting in a seat close to the orchestra. Admittedly, there isn't any high-end audio equipment that I've ever had in my listening room that could make me think I'm listening to an actual 100-plus-member orchestra. Still, since the separation of the instruments and the groups of instruments was rendered at such a high level, the emotional connection of this thrilling piece of music filled the front of my listening room. It enveloped me as the sound was enough to make the experience akin to attending a live event.

Naim Audio's NVC TT / NPX TT phono stage combo reproduced every instrument with a significant amount of treble energy, which included almost every instrument on the left side of the orchestra, with an astounding amount of realism and lack of audible distortion. This was especially true of the percussion instruments at the rear of the soundstage, particularly the metallic "ping" and crash of the cymbals and other metallic percussion that added to the realism I enjoyed throughout this masterpiece.

What I should have mentioned earlier was the full chorus that is featured throughout this piece. Reproducing a large chorus without any groove distortion is often the Achilles Heel of LP playback. What I heard while playing this LP was one of the most enjoyable parts of this listening session. Of course, there is much more to eliminating this distortion than just a good phono stage, but the contribution of the Naim phono stage setup was obvious. The lack of audible distortion allowed me to identify individual voices within the large group of vocalists. It also let the entire chorus wash over me when they reached their crescendos.

When a solo mezzo-soprano entered during the emotional "The Field Of The Dead," which was the sixth (the second to last) movement, where the vocalist describes the scene where a girl seeks her lost lover and the scene of her kissing the eyelids of all the dead. I nearly spilled my beverage when the chorus rejoined the orchestra during the weighty last movement.

Since the low-output moving coil Top Wing Suzaku, "Red Sparrow" phono cartridge I used for this review only had an output of 0.2 mV, and the gain settings of the NVC TT phono stage weren't as high as my reference phono stage, I had to turn the volume of my line stage / preamplifier much higher than I usually do. Thankfully, both these Naim components that were being reviewed had a pitch-black background and zero background noise. Even when I turned my linestage's volume twice as high as when listening to a digital source, this higher linestage volume hardly mattered. That is, as long as I remembered to set it lower when I switched to a digital source.

Sound Of The Naim Audio NAP 350 Monoblock Amps
For kicks, I listened to a CD rip of Yuri Temirkanov conducting Alexander Nevsky with the St. Petersburg Philharmonic that was released in 1996. I considered the sound quality of this CD to be good when I first heard it way back when, and for a standard 16-bit/44.1kHz "CD quality" rip, it still holds up.

The soundstage and other sonic characteristics, such as its massive bass reproduction, smooth and realistic midrange, and the sparkling treble of these Naim monoblocks became highly apparent during my first listen to this reading in quite a while. During the climactic "The Battle On The Ice" movement, I could hear the metallic percussion instruments that originated on the orchestra's left side reverberating off the venue's right wall. This might have been the equivalence of a parlor trick when compared to more essential traits such as the NAP 350s' liquid-sounding midrange, which gave the St. Petersburg strings a lifelike, compelling sound, but taken as a whole, I couldn't help myself, as I listened to the entire CD from beginning to end.

The file was made from ripping a CD I purchased in the 1990s, forcing me to retract my statement that the soundstage of the Naim Audio NAP 350s depended on the sound quality of the recording more than anything else. This was a decent recording, but it couldn't come close to some of my collection's vinyl or DSD versions or those I could stream. Regardless, I enjoyed this version very much thanks to the power and glory of the Naim NAP 350 monoblocks.

I was lucky enough to hear producer Tony Visconti give a talk on making T.Rex's Electric Warrior album. All of the other popular T. Rex albums were recorded in the UK, but this album was recorded in a more electronically sophisticated NY studio. The early 1970s saw advances in multi-track technology, and Visconti wanted to take advantage of this. It was at least in part because they traveled to New York City to record this album that turned out to be T. Rex's best-selling album, and what many consider his best.

Thankfully I have a few excellent-sounding copies of this album, including the two-LP 45 rpm Mobile Fidelity Sound Lab vinyl, and a Japanese SACD that was ripped to my computer-based music server. The computer's USB output, via a Wireworld Platinum Starlight 7 USB cable, was connected to the USB input of a Simaudio MOON 681 DAC. Regardless of which version I played the Naim NAP 350 monoblocks were able to transfer to my speakers a transparent signal that it was sent from my linestage.

The Naim Audio NAP 350 monoblocks were able to demonstrate not only the brilliance of T.Rex's epitome of 1970s glam, but also Tony Visconti's excellent production. Visconti had a way of sorting everything out, regardless of how many instruments were playing at the time. It was the opposite of Phil Spector's "Wall Of Sound", which meant that every instrument, sound, and voice was separated into its own area of the soundstage Tony Visconti created.

The musicians on this album were far from virtuosos, yet everything seemingly magically came together to produce this masterpiece of an album. Flo and Eddie's background vocals floated above the proceedings, T. Rex's vocals were cemented in space between the two speakers, the drumset was spread through the soundstage, each drum and cymbal separated from the rest, not stepping on any of the sounds that the musicians and vocalists created. It was as if I was listening to the master tape played back in my listening room. I played to the album from beginning to end, and then listened to it again.

Naim Audio Wins
Both the Naim Audio NAP 350 monoblocks and the NVC TT phono stage with NPX TT power supply are worth every penny of their asking price. No, these components are not in the "affordable" category of high-end audio equipment, but I can easily recommend them as essential pieces of a top-flight high-end audio system. They look great, are user-friendly, and sound as good as any other components I've ever heard anywhere near and quite above their price class. If one were to borrow money to be able to afford these two fine components, and by association, Naim Audio's NAC 332 line stage, I would totally understand.

Specifications
NAP 350 Monoblocks
Frequency Response: -3dB @ 1.4Hz to 100kHz
Power output: 175 Watts 8 Ohm @ 0.1% THD+N (195W @1%)
345 Watts 4 Ohm @1% THD+N
Gain: +29dB
Inputs: 47kOhm True balanced via XLR and 34kOhm unbalanced via legacy adaptor lead
Peak Current Into 1 Ohm (1kHz 1mS): +/-42 amps peak (1.7kW peak power)
THD+N at 2/3rds full power 8 Ohm @ 1kHz: 0.006%
Input signal for clipping: 1.33V RMS
Signal-To-Noise Ratio: 91dB A-weighted @ 1W / 8 Ohm
Damping Factor: 36
Dimensions: 3.575" x 17" x 12.5" (HxWxD)
Weight: 36.38 lbs.
Price: $8499 each

NVC TT Phono Stage
Product Type: MM/MC Phono Stage
Audio Output : 8 Vrms Maximum
Headroom: MM: 22dB ref 5mV input
MC: 23dB ref 0.5mV input low gain setting, 17dB ref 0.5mV high gain setting
Audio Inputs: MM: (Partial) – 2dB at 20Hz and -3dB at 14Hz
Audio Inputs: Power Amp In +/-18V DC @ 300mA
Audio Outputs: Powered Accessory Sockets Stereo RCA
Crosstalk: MM: >75dB
THD + N: MM: <0.005% ref 50mV input
          MC (low & high gain): <0.005% ref 1.5mV input
Signal-to-Noise Ratio: MM: 83dB réf. 5 mV A-wtd
          MC (low & high gain): 84dB ref 0.5mV A-wtd (both gain settings)
Gain: MM: 42dB MC (low & high gain): 61dB low gain and 67dB high gain (switchable)
Phono Specific RIAA Accuracy: MM: +/-0.1dB
Weight: 7.5 lbs.
Output: Unbalanced RCA, 5-pin DIN, and 8-pin DIN
Price: $3,699

NPX TT Power Supply
Weight: 12.35 lbs.
Dimensions: 2.75" x 8.375" x 13" (HxWxD)
Mains Supply: 110 to 120V, 220 to 240Vac
Power Supply Output: Type 1 and Type 2
Price: $3,699

Company Information
Naim Audio Ltd.
Southampton Road
Salisbury
SP1 2LN
England

Voice +44 (0) 1722 426 600
Website: NaimAudio.com

North America Distributor:
Focal Naim America
Website: FocalNaimAmerica.com