The frequency of this circuit depends on C1 and, for the indicated values, it is 1 kHz. Equivalent operational amplifiers can be used, and the power supply must be symmetrical.
The scratching noise is quite unpleasant for those who pass the sound of vinyl records to other...
This circuit for common analog telephones was found in March 1982 Radio Electronics magazine. It...
In the figure we have an RF amplifier for tunnel diode. The frequency range will depend on the...