Naim NAP 135 Monoblock Amplifiers (1986)

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 al high dissipation will cause the NAP 135 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 in a similar way, 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 135 has two regulated power supplies, each of which is rated at 40 volts and able to deliver more than 10 amps continuously.
The NAP 135 is a mono amplifier and has a temperature controlled fan mounted on a large internal heatsink to assist cooling when being used at high dissipation levels. High quality components are used throughout, with great attention to detail construction. Many components are specially selected or manufactured to our own specification.

Power Output: 75 W into 8 Ω
Transient: 500 VA
Voltage Gain: +29 dB
Input Impedance: 22 kΩ
Operating Temperature: 0 – 50°C
Mains Supply: 240 V, 220 V, or 120 V; 50 or 60 Hz
Dimensions: 430 (W) x 300 (D) x 76 (H) mm

Turnaround

Orders will usually dispatched within 2 working days of receiving cleared payment.

Shipping Rates

We calculate your shipping rate based on the total weight of your items and your delivery address. Standard shipping to the UK Mainland is free, except where specifically indicated. Don't worry, you'll always see the final shipping charge displayed before you reach the payment step (on the checkout page).

Carriers

We despatch the bulk of our UK mainland items on a 24 hour service.  Non-Mainland locations – Isle of Man, Isle of Wight, the Scilly Isles, the Scottish highlands and Islands, the Channel Islands and Northern Ireland may take a day or so longer. Smaller items are delivered using Royal Mail 24 or special delivery. Larger items are delivered using a courier service such as UPS and occasionally by a Pallet service.

Order Tracking

If a tracking # is provided by the carrier, we will update your order with the tracking information. Please note that some orders will not have tracking numbers.