Technical Features
NAC S1 Preamplifier
New Electronic Design
The NAC S1 features a completely new electronic design, optimised from the ground up for sound quality. At the input stages in the lower enclosure all switching is mounted on a brass frame which is suspended using a leaf-spring system to decouple it from mechanical vibration. It is also covered by an inert metallic cage to dissipate electromagnetic radiation. The signal is converted to balanced within the lower half before being sent through the acrylic divide to the main analogue boards which are isolated in their own spring-loaded suspension system (see below) in the top section. All inputs are also individually isolated from each other so there is no detriment to performance when multiple sources are connected.
Dual Volume Control
NAC S1 combines two established methods of volume control in an innovative new solution: the Naim dual volume control.
There are numerous ways to design an audiophile volume control, each with their own advantages and setbacks. The stepped attenuator can sound great but it does, however, come with one disadvantage in that the sound tends to be uneven during volume change. The new Naim DVC includes a chip volume control that is used while changing volume to allow a smooth progression of change. The millisecond the volume is fixed the electronic volume control switches completely out of circuit back to the now set stepped attenuator.
The Naim dual volume control also uses a fixed set of single resistors to achieve each of its 100 volume possibilities so that combinations of resistors - creating multiple signal paths and multiple path lengths ‘blurring the signal’ - aren’t used.
Vertical Suspension
The Statement preamplifier takes a technique pioneered by the 500 Series range and applies it in an innovative new way. All the sensitive audio electronics are mounted on a brass plate and suspended vertically within the top section. The board has a resonant frequency at 9Hz (below the threshold of human hearing), eliminating microphonic interference.
DR (Discrete Regulator) Technology
A bespoke version of the Naim DR circuit has been applied to supply each audio stage of the NAC S1 preamplifier. A board containing the DRs is mounted in parallel with each audio stage within the vertical suspension system. This means that each stage has its own independent DR supply which is mounted in such a way as to supply the voltage along the shortest possible path.
Internal Shielding
In addition to all the measures taken to maintain maximum fidelity through electronic layout and suspension systems, further internal shielding is used on the NAC S1 to isolate critical electronics from electromagnetic, thermal, acoustic and mechanical interference which can adversely affect sound quality. Input switching is suspended on a brass frame and housed within an inert metallic cage to protect circuitry. Individual analogue components which are critical to sound are also housed within their own protective casings.
NAP S1 Mono Power Amplifier(s)
One Horsepower
Each Statement mono power amplifier features a massive 4000 VA transformer mounted vertically on an A-frame in the lower box. Any vibration and noise from the transformer are transferred directly through the frame to the floor spikes away from sensitive electronics above.
Each amplifier is rated at 746 watts (one horse power) into 8 ohms, 1450 watts into 4 ohms and 9000 watts burst power into 1 ohm.
It’s a true Naim amplifier to its core, with serious stable power capable of driving the very best high-end loudspeakers.
New Three-Stage Electronic Design
The NAP S1 electronic design is also completely new. It is a bridged design, which uses three short stages with only the first, the instrumentation voltage gain, using negative feedback. The second is an ultra-fast error cancellation system; the third is the unity gain high current output buffer.
The delicate voltage stage sits at the very top of the upper section, completely separate from the current amplification which sits at the bottom. Each stage is optimised for only one task and the result is genuinely state of the art performance.
No Global Feedback
By breaking the feedback loop the speed of the amplifier is guaranteed to be far in excess of what is needed to achieve the demanding new power levels and bandwidth. Secondly, this also means the dynamic loading of the speaker is isolated from the delicate gain stages. The gain stages are then free and always working into a known load.
ALN (Aluminium Nitride) 009 Output Transistors
Naim has worked with a specialist semi-conductor manufacturer whose electronic components find applications in aerospace, military and space exploration, to develop a new kind of transistor.
The bespoke 009 output transistor utilises Aluminium Nitride (ALN) - a substrate that has ten times the thermal conductivity of traditional Aluminium Oxide. The result is a transistor running with the maximum possible temperature stability for maximum linearity.
Nano Diamond
In order to create the best contact between the new custom ALN transistors and the heat sink a new paste was used which contains tiny particles of diamond. This enhances its thermal conductivity to be more than nine times greater than the standard:
Regular contact paste is 0.9 w/mk
New nano diamond = 8.3 w/mk
(w/mk = Watts per metre kelvin – standard unit of thermal conductivity)
DR (Discreet Regulator) Technology
Bespoke DR regulators are used throughout the NAP S1 to supply ultra-stable, low-noise power to critical electronics. The Statement DRs have been designed specifically for this application as they have to handle 50 times the current and almost 3 times the voltage of a standard Naim DR.
Craft
Aluminium Heat Sinks
NAP S1 heat sinks start out as a solid billet of untreated aluminium. This is then cut to size and machined to achieve the general curve profile. The fins are then cut using a five-axis CNC machine with coolant continually fired at the tool to control the temperature. Over the course of several hours the finished shape emerges. Once each piece is individually machined it is then meticulously hand-polished, bead-blasted and anodised in another specialist facility.
It took hundreds of prototypes and collaborations with different specialists to perfect the creation of the distinctive sculptural effect.
Acrylic Divide
The acrylic centre-piece is a non-conductive material which defines the physical barrier between the two main sections of each product. It is skilfully crafted from solid and the Naim logo is machined in. Inside surfaces are bead blasted to achieve the unique diffraction of light to illuminate the logo. The effect is that the top half of the product appears to be suspended on a blade of pure light.
Glass Input Bar
The glass of the input bar of the preamplifier is flame-polished and laser-etched with the input displays. This was designed to conceal the source of the light and has the appearance that the inputs are suspended within the glass.
Small Parts
The same attention to detail that goes into the massive case work is also given to tiny internal components. No stone is left unturned in our pursuit of performance. Even small metallic parts, such as the copper busbar which bridges capacitors in the power amplifier, are custom-designed for optimum performance.
Specifications
NAC S1 Preamplifier
Inputs: 3 X DIN, 3 X RCA, 2 X Balanced
Output: 1 X Balanced, 2 X Unbalanced (4 pin DIN sockets)
Weight: 61.5kg
Dimensions (HxWxD): 940 x 270 x 412mm (width includes stabiliser)
NAP S1 Mono power amplifiers
Inputs: 1 x XLR (each)
Outputs: Binding posts for spade & 4mm banana
Power output: 746W into 8 ohms, 1450W into 4 ohms, 9000W burst power into 1 ohm
Weight: 101kg (each)
Dimensions (HxWxD): 940 x 256 x 383mm (each)