Description
Harman Kardon A401 – Stereo Control Amplifier
“The A-401 stereophonic control amplifier was designed in the USA and manufactured in Taiwan, and was designed with both sound and serviceability in mind. It features a pre-amplifier stage designed for a magnetic phono cartridge, tone controls, and quasi-complimentary output stage with a differential pair input to help keep distortion down.”
“A quasi-complimentary output stage is a type of push-pull output stage made from two identical NPN transistors connected between the supply rails, in contrast to a fully complimentary output stage which uses a mirrored pair of a PNP and NPN transistors. Quasi-complimentary designs were popular in the early days of transistor amplifiers, when NPN power transistors were easier to manufacture than PNP power transistors, but continued to be found in lower powered and entry level amplifiers for many years. They’re almost never used in modern construction as NPN and PNP power devices are equally available.”
Source: nutsvolts.com
