This passive circuit was found in a 1980s documentation. The circuit serves to indicate the balance or balance between the channels of a stereo amplifier.
This application of the RCA integrated circuit released at the time was found in the August 1970...
The transistors of this 12 V x 150 mA power source can be BC558 for PNP and BD135 for NPN. The...
This circuit was found in an Argentine publication from the 1970s. The circuit can be assembled with...