Naim NAIT

Insistent on the unimportance of specifications in general, Naim never published technical specifications for this low-powered design.[2][11][12] Trade speculation of its power output ranged from 5 to 15 watts per channel.[2] Naim confirmed years later that the NAIT is rated at 13 watts.[7][Note 2] Part of its mystique seemed to stem from its low power: in developing the successor to the NAIT, Naim founder Julian Vereker remarked that R&D "cooked up a more powerful version and presented it to me on my return [from holiday but] it sounded awful."[9]

In its product manual, the NAIT is said to have "low continuous power output ... balanced by a very large peak current capacity so there are no restrictions on the size or type of loudspeaker that may be used. But please don't expect the impossible".[13] Hi-Fi Journal wrote that "the NAIT excelled in musical terms ... and would comfortably drive loudspeakers that caused other amplifiers to sound lumpen and distinctly unmusical".[11] And for that reason, many people who owned the Quad Electrostatic Loudspeaker (ESL) – which are known to be a very difficult load for amplifiers[14] – would choose the NAIT to drive their speakers.[2] Reviewers attribute the perception of power of the NAITs to the over-engineered, dedicated power supplies that ensure generous current delivery for musical transients.[15]

As part of the 5-series redesign,[7] mechanical and electronic changes introduced in the NAIT 5i (italic 'i') include attention to wiring, control of internal heat dissipation, radio-frequency interference and mechanical vibration through more efficient materials, compliant mounting and decoupling.[16][17] The SUPERNAIT benefits from a fully active line-level preamp developed for the NAC 552 pre-amplifier, and its output section is derived largely from the NAP 200 power amplifier.[18]

In launching the 2013 NAIT range, Steve Sells, electronic design manager of Naim, explained how the new NAITs fulfilled the goal of delivering sound quality performance. They are stripped of superfluous components and features, and as such, the digital–analogue converter (DAC) previously available on the SUPERNAIT has not found its way into its successor.[17] The transformer is deliberately positioned as far away as possible from the inputs to avoid electromagnetic interference, while the power supply and its capacitors are closer to both the transformer and the output devices.[17][18] Non-audio circuitry for controlling the amplifiers are optically isolated from signal sections, and are designed to power down when not in use, to avoid interference.[17]

While reviewers criticised the styling of early NAITs of having a distinctly cottagey feel,[19][20] Ian White observed that the typical Naim product is "meticulously laid out, clean, and well put together".[21] Housed in the same small, black "half-size" aluminium cases used by Naim pre-amplifiers and power supplies,[2] the electronic components are of high quality and discrete – with few or no integrated circuits,[2][9][12] mounted on a single, printed circuit board. For many years, Holden & Fisher supplied custom-made toroidal transformers used in the amplifiers. The ones used in NAIT were rated 100 VA,[2] but these have been progressively up-rated over the years, with consequent increases in power output: the entry-level NAIT 5si has a powerful 300 VA transformer for the delivery of 60 W of rated output.[22]

While Naim's practice of using DIN connectors has been regarded by some reviewers as quirky or arrogant,[19][23] DIN sockets continue to be Naim's choice for line-level inputs. From standard DIN sockets used in the "half-size" NAITs, Naim upgraded to higher-quality locking DIN sockets on the NAIT 3. However, models since the NAIT 5i include a number of hard-wired parallel inputs using RCA sockets.[8][24] As the NAIT was conceived as an entry-level offering, the RCA connector – undoubtedly more popular with mass-market equipment – was offered in place of the BNC for the phono source.[2] In all 2013 models, RCA inputs double the DIN counterparts.[17][24] Banana plugs,[25] the absence of tone controls,[26] the tendency to harshness when cold[11][18][24][25][27] are family traits inherited by the NAIT.

"NAIT 1" to NAIT 3 have hard-wired mains cables. Since NAIT 3, the on–off switch has been located on the back of the amplifier – given that units are meant to be permanently switched on; since NAIT 5, power is delivered through a detachable mains cable via an IEC connector fixed to the back panel.[24] Consequently, the front panel looks more minimalistic.[7]

The 2013 range of Naim equipment has aluminium chassis and sleeves; the fascia is die-cast zinc.[17] Inside, circuit boards float, and the rear-mounted mains switch and IEC socket are decoupled to reduce microphony.[28] Techradar noted that the XS, launched in late 2008, is the first Naim device to use a new bayonet PCB-mounting technique to float the circuitry.[28]

Back of the Olive NAIT 2 (factory-modified to work as a preamp-only unit). There are recessed banana sockets for speakers, three DIN inputs and one pair of RCA phono sockets

There are two major variants of the NAIT, and apparently several minor variants with different motherboards. The simplest and most notable distinction between older and later models is the LED on the fascia: the red LED on the earlier NAIT became a green one on the later model.[2] The balance control unusually only attenuated the left channel by up to −3 dB;[2][7] the lack of obvious markings to indicate a central position was criticised for being "slightly confusing".[2][11]

Tellig was ambivalent about the NAIT 1 in Stereophile: noting that it was "a good-sounding little amp", he criticised it for "look[ing] very cheaply made, inside and out", and for its lack of features, particularly the absence of an 'aux' or 'CD' input, tone controls, or moving coil input.[26]

The "chrome bumper" NAIT 2 was designed to be factory-modified to work as a preamp-only unit. The upgrade path is assured by partnering with Naim's own stereo power amplifiers – in particular, the NAP 90 and NAP 140, both of whose in-built power supplies can power their own pre-amplifiers.[12]

The NAIT 3 is derived from the NAC 92 preamplifier and the NAP 90/3 power amplifier with which it was launched – it is basically the NAC 92 and NAP 90/3 in one box.[30] Its flat slimline Olive case with rounded edges measures 17 by 12 by 2.2 inches (432 mm × 305 mm × 56 mm).[7] The NAIT 3, costing £500 at its launch, has five line inputs.[31]

Back of a NAIT 3, showing the 4 DIN sockets and 1 pair of RCA sockets

A remote control version, identified by the 'NAIT 3R' designation, was released in 1995. The NAIT 3 can be upgraded to 'R' specification by adding a separate remote control board.[7] Ian White said its construction, fit and finish and performance/cost ratio made it a price-point leader.[30]

The NAIT 5 was successor to the '3'.[3][20][21] It is housed in the same low-vibration black die-cast alloy casing employed in the '5 Series', and measures 17.2 by 12 by 2.3 inches (43.7 cm × 30.5 cm × 5.8 cm).[20][21] and employs surface-mount technology.[7] Like its brethren, attention is paid to protecting the circuit boards from vibration.[21] The remote control function of the NAIT 5 is a new feature to the NAIT, and allows volume and the balance adjustment.[21]

The NAIT is henceforth a range extended across its three series – the entry-level 'i Series', XS, and Classic series.[Note 3] The three units all share a styling, but the height of the case increases for the higher models.

All three NAITs of the range from the back, showing doubled-up input sockets and banana speaker sockets

The 50-watt NAIT 5i[32] replaces the 30-watt NAIT 5. The phono input has been banished, so owners of turntables would need to plug a head amp (phono pre-amplifier) into one of the line inputs.[11][24] Styling is similar to its predecessor, with basic black with green fluorescent highlights. However, it has fewer selector buttons on the right side of the face-plate.[24] When the SUPERNAIT was launched in 2007, the 5i was upgraded to the "italic specification" NAIT 5i.[10][16][25]

The NAIT 5i (italic 'i') has an additional 3.5mm jack for portable devices on the front panel, reviewers noted sonic improvements "from the first track"; it is demonstrably better at handling higher sound pressure levels than the '5i'.[16]

NAIT XS:[Note 4] Reviewers have described the XS as a "SUPERNAIT in the slimmer casework of the Series S".[4][8] It also has a 3.5mm stereo input with auto-switching on the front-panel, suitable for an MP3 player. A powered input, provided for turntable users, is designed to supply one of Naim's external phono pre-amplifiers.[4][8][28] The unity gain option and AV bypass function allow it to be used in conjunction with an AV processor in a home cinema system.[28] It also includes optional RS-232 interface for custom installations.[8][28]

The SUPERNAIT, released in 2007, incorporates two coaxial and three optical inputs, including a combination mini-jack/mini-Toslink connector with auto-switching on the front panel connectivity for digital sources that facilitate direct connection of computers, media servers and the like.[15][33] Its circuitry is supposedly identical to that of the XS,[33] but has a 24-bit DAC that can be called from any of five S/PDIF inputs.[18] It has more features, a more well-endowed power supply allowing delivery of 80 watts' music, and can bi-amp suitable speakers by adding a secondary power amplifier.[15][34]

To mark the 40th anniversary of Naim Audio and the 30th birthday of the original NAIT, Naim unveiled a new 3-product range under the NAIT brand: the NAIT 5si, NAIT XS 2 and SUPERNAIT 2. The range has seen a general uprating of the transformer compared with the versions they replaced, allowing for better power delivery. The manufacturer claims use of better components in critical areas and new circuitry. All three models have built-in headphone amplifiers. The digital–analogue converter has been removed as being available either as a separate unit, or as part of the Uniti.[17][35]

The NAIT 5si is the entry-level NAIT and the direct replacement of the NAIT 5i (with italic 'i');[17][35] the NAIT XS 2 is positioned as the mid-range product.[17][35] The SUPERNAIT 2, the flagship integrated amplifier in the Naim stable individually decoupled inputs and no digital circuitry. Both incorporate a headphone output via a class-A headphone amplifier.[17][35][Note 5]