This amplifier is from Motorola documentation from the 70s. The circuit uses transistors from the time, which are not common today, such as the SE7005 or 2N3916 at the output.
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....