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 very high input impedance circuit is suggested by Texas Instruments. The circuit can be...
We found this circuit in the August 1994 issue of Electronics Now magazine. The circuit is based on...
This bargraph circuit using LM3914 was found in the October 1980 Radio Electronics magazine. Note...