Transistor Amplifiers continued 4

Here a design from 1975 of Popular Electronics employing plastic transistors, but still the same early transistors.

 

Below a European quality high power amp of more sophisticated design from 1974 (ETI). It is capable of delivering 100W to the speakers in class AB configuration and using parallel final transistors. The transistors used are still early models produced by Motorola and Philips:

Below a 1984 symmetric mosfet amp (Elektor). This is a 50W version, but can be made easely into a 100 to 300W version. In all modern today designs the principles of mosfet power amp design are found within this. 

 Click here to goto page 5 of this section.

©Hans Hilberink PE1MMK 04-11-2001.