This is a Japanese commercial radio from the 60s. The superheterodyne circuit of 7 transistors for medium waves has 200mW of output when powered by 4 common batteries.
This is the traditional configuration of an AC amplifier using the 741 integrated circuit. I found...
This article is old, from 1994. But, for those who have an old PC and want to use a joystick from...
This simple circuit indicates when the two channels of stereo equipment are balanced. The diodes can...