NAD Electronics
NAD (an acronym for New Acoustic Dimension) is a Canadian producer of low cost home audiophile amplifiers and components owned by the Lenbrook Group of Pickering, Ontario, Canada[1]. Its most famous product is the late-1970s NAD 3020 amplifier, designed by Bjorn Erik Edvardsen, which became a staple of low budget Hi Fi in Britain, where the company was originally founded. The company's philosophy is to include only genuinely useful features and leave out flashing lights and seldom used buttons, leading to an understated elegance to the products when compared with typical Japanese designs, for example. Another important philosophy is to use leading-edge designers but to contract in most cases for lower cost manufacture on a product by product basis, typically in Asia. This allows truly innovative and high-quality products that can be sold at very competitive prices.
One area where NAD is notable for its innovation is in amplifier design where their small and affordable amplifiers are well regarded for delivering very high fidelity and an extremely "musical" sound with power capabilities typical of much larger and more expensive amplifiers. The keys to this achievement are: (1) an innovative approach to the design of the power supply feeding the amplifier and (2) the inclusion of a user defeatable "soft clipping" circuit.
Power Supply design
NAD focuses on the concept of "effective power" and its amplifiers have been known for delivering generous headroom, meaning that they can deliver dynamic power bursts far in excess of their rated RMS power. The key to this feature is to use a flexible power supply which stores significant reserve current for quick release at moments of high musical load. The various incarnations of this design have been associated with different names over the years including "Power Envelope™" and recently "PowerDrive™". Additional benefits of this approach include the fact that amplifiers using this technology can handle complex, real-life, lower-impedance loudspeaker loads as compared with the simple 8-ohm resistor typically used to calculate advertised power ratings and the fact that the circuitry in this approach requires less cooling, while maintaining ability to handle complex impedance loads as low as 2 ohms.
Clipping protection
Amplifiers which are overdriven (pushed beyond their designed power capabilities) will produce audible distortion referred to as clipping. The term refers to the fact that the music waveform is harshly cut off at the extremes resulting in unpleasant and potentially speaker-damaging distortion, particularly tweeters. The user-defeatable "Soft Clipping" circuit on NAD amplifiers gently transforms the music waveform as the point of clipping approaches, resulting in much clearer reproduction and simultaneous protection of speakers.
Current products (and those from the past few years) have a remote control communications bus named 'NAD Link', connections for which are provided on a pair of RCA phono sockets on the rear panel.
Naming scheme
There is a general pattern to the model number prefixes:
- denotes a preamplifier
- denotes a power amplifier
- denotes an integrated amplifier (the idea that 2 plus 1 equals 3)
- denotes a tuner
- denotes a playback unit either a CD player, DVD player or turntable
- denotes a recording device such as a CD recorder or cassette deck
- denotes a receiver (3 'from' an integrated amplifier plus 4 'from' a tuner)
- denotes a multi-channel power amplifier