In addition to tone control, this circuit of the SGS 1982 linear integrated circuit manual has a loudness control. The supply must be made with a 24V voltage source.
This detector or window comparator was suggested by Harris in documentation from the 90's. The...
This circuit was found in a 90s Hands-On Electronics. When a signal appears at the headphone...
This circuit produces low power flashes in a LED. Frequency is adjusted by P1 and depends also on...