This organ, played by a probe was found in no old documentation, but it can be easily implemented these days. The integrated circuits are 555. The trimpot allows individual tuning of the keys.
This circuit that uses only transistors indicates when the voltage in the circuit has the voltage...
This power supply makes use of a capacitance multiplier. C2 can be 100 uF which with the action of...
Found in an English publication from the 70's, this radio uses a germanium transistor and requires...