Naim NAP 140 Power Amplifier (1988)

Here we have a super little NAP 140 power amplifier from British specialist Naim Audio. Originally launched way back in 1986 in the half width case with the “chrome bumper” finish, this model is still a very highly regarded amplifier, and seen as one of the first steps onto the vintage Naim ladder. In good fully working condition, noting a few minor blemishes – please refer to photographs. It comes in suitably packaged, with mains cable, 4-pin SNAIC cable and our standard three month warranty.
Naim Say….
The purpose of an audio amplifier is to drive loudspeakers without loss of musical information. In our view many commonly accepted parameters have little to do with loss of information and in some instances, such as the pursuit of large bandwidths or low distortion, unqualified acceptance of them can actually lead to the creation of mechanisms that bring such losses about. Dynamic output impedance, open loop bandwidth, slew rate, propagation delay and stability margins are only some of the many factors to which we attach Importance, and which must all be brought into positive balance.
With this balance in view, our amplifiers not only achieve low harmonic distortion low noise and wide power bandwidth, but also have a constant dynamic output impedance over the whole audio bandwidth. They are able to drive reactive loads without any appreciable change in distortion and are not sensitive to the absolute impedance of the load.
The frequency response of our amplifiers at the bass end is dependent on the gain decoupling capacitor, and the half power bandwidth extends to below 5Hz. At the top end the response is controlled by a passive single pole filter and is 3dB down at 40kHz. The amplifiers do not slew rate limit within this frequency bandwidth.
The amplifiers will tolerate any load from 0 ohms to infinity without damage or instability, the output stages being protected by circuitry that measures the power dissipated. Prolonged running at high dissipation will cause the NAP 140 to become quite warm and should the heatsink temperature exceed 70°C the mains supply will be interrupted until the amplifier has cooled down.
The cases of the power amplifiers are all constructed using a heavy aluminium extrusion, which acts as a heatsink, to form the outer cover for an inner chassis inside which the entire amplifier is assembled. All connections are on the rear. All the amplifiers have large toroidal mains transformers. The NAP 140 has dual rectification, and each channel has its own pair of smoothing capacitors.
The NAP 140 has a built-in 24V regulated supply to power Naim Audio pre-amplifiers via a SNAIC-4 interconnect cable.
High quality components are used throughout, with great attention to detail construction. Many components are specially selected or manufactured to our own specification.
Specifications:
Power output: 45 W into 8 ohms
Input impedance: 22 kΩ
Mains supply: 240 V,220 V or 120 V, 50 or 60 Hz
Operating temperature: 0 to 50°C
Dimensions: 205 (W) x 300 (D) x 76 (H) mm

For a vintage review from US publication Stereophile please click HERE