This simple audio signal tracer or follower can be made with a BC548 instead of the original transistor. The output is made in a small crystal phone. The power can be from 5 to 9V.
Found in the April 1980 issue of Radio Electronics magazine, this stage uses transistors from the...
This audio amplifier has an internal DC volume control with logarithmic characteristics and a...
This circuit was found in RCA and General Electric documentation from the 1980s. The circuit has...