The circuit below shows a 4-transistor utility amplifier suitable for a variety of projects including receivers, intercoms, microphones, telephone pick-up coils, and general audio monitoring. The ...

If you know anything about a transistor, it’s probably that it’s a three terminal device whose output pin forms part of a potential divider whose state is dependent on what is presented to its input ...

Reading an article about the first transistorized Hi-Fi amplifier, [Netzener] got the itch to make one. But what to use for the starting point? Enter an old Radio Shack P-Box stereo amplifier kit.