Richard Allan A21 amplifier

摘要

The November 1967 and March 1968 issues of Hi-Fi News carried two articles in which the operation of output stages in Class A and AB transistor amplifiers were compared at length. The results showed the superiority of Class A distortion figures, especially at low power levels. The author was a man whose name meant little to those involved in the domestic hi-fi scene: Jim Sugden. At the time, Sugden owned a company producing laboratory and test equipment, but thanks to a collaboration with Richard Allan, a company making speakers based nearby in Yorkshire, the first Class A amplifier made by Sugden was marketed under the Richard Allan name.