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 detector or window comparator was suggested by Harris in documentation from the 90's. The...
This circuit was found in documentation from the 1970s. It eliminates contact bouncing, providing...
Found in an American documentation, this circuit may employ general purpose transistors and the...