Free Circuit Diagram

The LM1894 is a stereo noise reduction circuit suitable for audio playback application. The DNR system is non-complementary, meaning that it does not require encoded source signal. The system is compatible with almost all prerecorded tapes and FM broadcasts. This noise reduction system uses  psycho-acoustic masking and an adaptive bandwidth filtering to achieve 10 dB [...]

What we can do with a stereo voltage-controlled volume control? There so many things, we can control our audio using a DAC which is controlled by a microcontroller, or we can use mono potentiometer with RC filter to minimize the scratched sound produced by a dirty potentiometer (I see this method in one of SONY [...]