This circuit of the 70's uses transistors of the time. The circuit can amplify signals from 10 Hz to 100 kHz and modern equivalent components can be used. The circuit is from Ferranti.
This circuit is from an old operational amplifiers manual. However, the setting applies to modern...
This circuit shows how a simple one-transistor stage can be used to Power high current loads from...
This amplifier for public address was found in English documentation from 1967. The transistors are from...