This circuit was obtained from the February 1992 Radio Electronics magazine. In it, a bar of 4 LEDs flashes continuously at a speed given by C1 and the setting of R3.
This circuit appears several times in this section and on this site, obtained from different...
This mixer with the integrated circuit CA3130 was obtained from an English publication from 1977....
This circuit is ideal for recovering vinyl media with a linear response from the RIAA curve of the...