This stereo circuit is from Japanese 1960 documentation. The circuit was originally designed to work with a tube amplifier, removing power from it. The transistors are germanium.
The diodes of this circuit are general-purpose, and the base resistors are typically between 2k2...
This oscillator that excites 3 LEDs sequentially is also called a circle oscillator. The frequency...
When this circuit picks up a louder sound it produces a pulse that briefly charges the 10 uF...