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.
January 2017 - The new Honeywell RSC TruStability ™ pressure sensor mounting board is available from...
With the appropriate choice of C1 and C2 it is possible to divide the frequency of a rectangular 3 V...
This circuit was obtained from an American publication from the 80's. We can use a BD136 instead...