This circuit, bridge type, was found in American documentation from the 60's. The transistor is germanium of the time.
This circuit uses a JFET CA3140 operational amplifier to convert a low frequency sinusoidal signal...
This circuit is from the National Semiconductor Audio Handbook. The amplifier operates with 6 V...
This simple amplifier was found in a Radio Electronics magazine from July 1970. The transistors are...