This balance indicator for stereo amplifiers was found in an 80's Elektor. The components used are common. Zeners are 1.8 V or close to that value.
This circuit is from an old National Semiconductor component manual. The circuit can be...
Found in Radio Electronics from the 90s, this circuit uses components from that time. However, it...
This circuit has been found in older telecommunications documentation. The circuit switches off after...