This circuit doubles the frequency of an audio signal, thus changing its timbre. The circuit was found in an Elektor from the 90s. The components are common today.
This synthesized generator circuit was found in an article in October 1980 Radio Electronics...
This circuit is from a publication in the United States in the 1980s. The basic integrated circuit...
This circuit was found in an American magazine in 1976. It doubles the frequency of TTL signals in the...