This 2-tube amplifier was found in a Japanese publication of 1964. The circuit has excellent sound quality. The power supply is not given and must provide a voltage of 300 V.
This simple source with zener regulation is ideal for experimental projects with operational...
This circuit is from a 1977 Signetics manual. BC107 transistors can be replaced with BC547 and...
In the figure we have an old circuit for controlling two low-power lamps. The circuit is from...