This balance control for the channels of a stereo system was found in a 1969 Mullard documentation. The transistors may be the modern BC548 equivalents.
This circuit is from an English book from the 1980s. Transistors can be general-purpose types of...
This circuit from the 80's can be easily implemented but needs some changes to avoid problems with...
The presented circuit provides an output voltage proportional to the input current, according to...