TDA7430/TDA7431 is a volume, tone (bass, middle and treble), balance (Left/Right) processors voice canceller for quality audio applications in car radio and Hi-Fi systems. They reproduce surround sound by using pro- grammable phase shifters and a signal matrix. Control of all the functions is accomplished by se- rial bus. The AC signal setting is obtained by resis- tor networks and switches combined with operational amplifiers. Thanks to the used BIPO- LAR/CMOS Technology, Low Distortion, Low Noise and DC stepping are obtained.