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 logic circuit can indicate both TTL (5 V) and CMOS (5 to 12 V) output levels, operating with...
We found this circuit in an old American documentation, from 1971, but the component used is still...
This circuit is from an Italian magazine Radio Elettronica of January 1977. The circuit shows how...