obiTuary

Björn Erik Edvardsen was the head of the British design team that created the best-selling amplifier in hi-fi history.

Björn Erik Edvardsen, head of the design team that created the NAD 3020 integrated amplifier, which many claim was the best-selling amplifier in the history of high fidelity, has died of cancer, aged 83. Edvardsen was already an up-and-coming electronics design engineer (Dolby Laboratories, Acoustic Research) when in 1976 he was hired by Dr Martin (Marty) L. Borish to work at NAD in the UK, which Borish had established in 1972 on behalf of a consortium of hi-fi distributors who financed the company. In 1977 Edvardsen delivered the NAD 3020 of which more than a million were eventually built. It was low-powered and low-priced ($259 in Australia at the time, but only £79 in the UK), and probably one of the ugliest amplifiers built during the 70s, but despite all this (or perhaps because of it) it achieved ‘cult’ status first in the UK and then around the world, which no doubt helped boost NAD’s sales figures. It was certainly a far better amplifier than the NAD 3030 that preceded it.

The NAD 3020 introduced the concept of Full Disclosure Power (FDP) in amplifier specifications (up until then, most amplifiers delivered the power output claimed for them only at certain frequencies and under specific operating conditions), and also introduced NAD’s now-famous ‘soft-clipping’ circuit, which reduced amount of ‘unpleasant’ distortion produced when a solid-state amplifier’s output stage is over-driven. Some critics claim that this circuit was required specifically because the NAD 3020 was so low-powered that it was very easy to over-drive.

However, despite its low rated output of 20-watts per channel, the NAD 3020 was easily able to deliver far higher power levels (40-watts into 8Ω, 58-watts into 4Ω and 72-watts into 2Ω, according to reviews at the time) because it had a high-voltage rail, used high-power output transistors and had a barely-regulated power supply, so it could very briefly sustain much higher output levels even into fairly low impedance loads. However, some critics at the time said that NAD was deliberately under-stating the power rating to garner publicity and reviewer credit for how much it exceeded the rating.

That said, the 3020 design appealed to audiophiles not simply because of the low pricing and the power output, but also because the preamplifier and power amplifier sections could be split from each other, offering an instant upgrade path, and both the tone and loudness contour circuits could be bypassed. It was also one of the first amplifiers to use LEDs to indicate power output, rather than the traditional VU meters that were common back then. It’s an indicator of its success that The Absolute Sound (TAS) recently included the NAD 3020 as one of its ‘ten most significant amplifiers of all time.’

Edvardsen continued to work for NAD either as an employee or as a consultant (he had his own company BE Electronics) after Borish sold it to Peter Lyngdorf, of AudioNord in 1991. He then stayed with NAD when Lyngdorf sold it to the Lenbrook Group of Pickering, Ontario, Canada in 1999, at which time he was appointed ‘Director of Advanced Research’ at NAD.