Scratch is the scratching noise that occurs mainly with old records. This high frequency noise is eliminated by the filter found in the February 1990 issue of Radio Electronics magazine.
This circuit was obtained in a 1989 English magazine. Despite using a fixed 5 V regulator, it can...
With the feedback of the output circuit, the monostable acts as a frequency divider, that is, it...
In this circuit of an old American documentation, the input impedance is the same as the output...