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.
We found this receiver on a single chip in the 1976 Siemens integrated circuits manual. The...
Found in Radio Electronics from the 90s, this circuit has several outputs with different pulse...
We found this circuit in an English publication from the 60's. The transistors are of germanium of the...