The device below is built as an active stereo-tone/volume control for TV receivers, car radios and mains-fed equipment. The device below has function for bass and treble control, volume control with built-in contour (can be switched off) and balance.
We can control all these function using dc voltages or by single linear potentiometers. This device has 4 features. The features are few external components necessary, low noise due to internal gain, bass emphasis can be increased by a double-pole low-pass filter, and wide power supply voltage range. [Circuit’s schematic diagram source: nxp.com]