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 found in a 1993 Electronics Hobbyst Handbook has a very simple configuration that can be used on...
Suggested by Motorola documentation from the 1980s, this circuit can be implemented with...
This circuit was found in a 1970 IEEE publication. The circuit functions as a voltage controlled...