This circuit is from the 70s. The integrated circuit used is not common today and the supply is made with a voltage found in televisions of the time, where it was used.
This is the traditional configuration of a 6 or 12 V source with 7806 or 7812 integrated circuits, for a...
This fader or guitar fading circuit was found in an American documentation from the 1980s. The...
Found in documentation from the 1960s, this power supply employs germanium diodes from the time....