The LM4610 is a DC controlled tone (bass/treble), volume and balance circuit for stereo applications in car radio, TV and audio systems. It also features National's 3D-Sound Circuitry which can be externally adjusted via a simple RC Network. An additional control input allows loudness compensation to be simply effected. Four control inputs provide control of the bass, treble, balance and volume functions through application of DC voltages from a remote control system or, alternatively, from four potentiometers which may be biased from a zener regulated supply provided on the circuit. Each tone response is defined by a single capacitor chosen to give the desired characteristic.