This 6-tube two-channel amplifier was found in an American documentation from 1947. The circuit is two-channel with a separation of bass and treble.
Found in a European magazine from the 90s, this circuit emits beeps that are several seconds apart to...
This is a battery powered 3W power amplifier using germanium transistors. The circuit is from an...
This circuit was found in Raytheon's 1967 documentation. The circuit uses an operating of the era,...