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 simple preamplifier was published in Radio Electronics magazine in February 1958. The battery...
The sensors in this circuit are NTCs and PTCs that work in a differential way by directly...
This interesting op-amp signal generator circuit was found in a 1977 documentation. The circuit has...