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 high-gain digital amplifier uses general-purpose transistors. The supply voltage is logic...
We found this circuit in the March 1993 issue of Electronis Now magazine. The circuit uses common...
Using an LDR as a sensor and an operational amplifier this circuit was found in the Encyclopedia of...