This part is a kind of semiconductor called NE545.

Function of this product has Dolby B Noise Processor.

Manufacturers : Signetics

Image and pinout :

Some of the text within the PDF file :

EiInEtiEf, DESCRIPTION T h e N E 5 4 5 i s t h e m o n o l i t h i c i m p l e m e n t a t i o no f t h e D o l b y " B n o i s e r e d u c t i o n s y s t e m .T h i s c i r c u i t i s u s e d t o r e d u c et h e level of background noise introduced during recording and p l a y b a c ko f a u d i o s i g n a l s o n m a g n e t i ct a p e , a n d t o i m p r o v e t h e n o i s e l e v e l i n F M b r o a d c a s tr e c e p t i o n . T h i s c i r c u i t i s o f D o l b y L a b s . L i c e n s i n ga n d a v a i l a b l eo n l y t o l i c e n c e e s application information may be obtained from Dolby L a b s .L o n d o n o r N e w Y o r k . NOISE DOLBY.B PROCESSOR 545 INTEGRAIED LINEAR CIRCUITS ( T o pV i e w ) P I NC O N F I G U R A T I O N B PACKAGE Input Input By Pass Output [ ... ]

NE545 PDF Datasheet Download