This part is a kind of semiconductor called AN7591.

Function of this product has BASIC CIRCUIT.

Manufacturers : ETC

Image and pinout :

Some of the text within the PDF file :

AN7591 BASIC CIRCUIT 19V +V +V F1 una aportacion de vigilante2@hotmail.com V1 V2 2A + C1 19.5V 12 16v C7 10 UF + C4 100U 1uH 11 C1 4N7 R2 330 C3 47U 1.5v 2 + U1 AMP 1 L1 10 9.5v 3 R5 4R7 C2 4N7 R1 220 STBY D2 R7 1k8 1N4148 D1 6V8 6 4.5v 1 18 v 0 v 5 U2 AMP 2 + C8 10 uF + SPK1 8 OHMS + L2 1uH 4 1.5v R3 6K8 IN R4 470 C6 4N7 7 8 16v 9.5v R6 4R7 C5 100 U Q1 NPN 9 Este ic se usa como salida de audio en componentes de diversas marcas,el presente corresponde al mini componente Phillips mod.FW-C720.LA ASIGNACION DE PINES ES LA SIGUIENTE: http:/// 1-RF=RIPLE FILTER 2-NF 2 3-GND 1 4-NF 1 5-AUDIO IN 6-STAND BY 7-OUT 2 8-BOOST 2 9 GND 2 10-OUT 1 11-BOOST 1 12-+B 19VOLTS 18v 1.5v 0v 1.5v 0v 4.5v 9.5v 16v 0v 9,5v 16v 19v Nota los voltajes que presenta son los [ ... ]

AN7591 PDF Datasheet Download