The CXA1563M/S is a bipolar IC incorporating dual channel Dolby B-C type noise reduction (NR) system and Dolby S type switch. Dolby B-C-S type stereo system is completed by using this IC in conjunction with two CXA1417S or two CXA1417Q. A reduction in the number of external parts and small package have been achived due to the fact that the spectral skewing circuits are all on-chip.