How to build Symmetrical Preamplifier Class A

Description

This is a symmetrical amplification unit circuit, more composed, modified by a construction which was proposed some years ago by Lisley Hood. The most important reason is to get the right transistor FET at differential amplifier at input. In spite of all this it is a circuit which provides, current mirror stage of both sides, with the result of lessening the overall negative feedback. The exactness of the matches of the transistors - resistances are determined and for the details. The trimmer TR1, make less the offset voltage at input.

Circuit diagram

Part List

circuit from http://users.otenet.gr/~athsam/symmetrical_class_a_2.htm