This part is a kind of semiconductor called STK442-110.

Function of this product has 14 Pin / Class AB 2 Channels AF Power Amplifier.

Manufacturers : Sanyo

Image and pinout :

Some of the text within the PDF file :

SPECIFICATIONS No. STK442-110 1. Case Outline 14Pins (See attached outline drawing) 2. Function class AB 2 channels AF power amplifier 3. Application 70W audio use 4. Maximum Ratings / Ta=25deg. Item Power Supply Voltage 1 Power Supply Voltage 2 Thermal Resistance Junction Temperature Operating Substrate Temperature Storage Temperature Available Time for Load Short-circuit *4 Symbol Conditions Vcc max(1) No signal Vcc max(2) Signal ,R L=8ohm ,6ohm Theta j-c Per one power TR Tj max Tc max Tstg Vcc=+-38V,RL=6ohm,f=50Hz ts PO=70W,1ch drive 2000.06.05 TENTATIVE Ratings Unit +-61.5 V +-54 V 1.9 deg./W 150 deg. 125 deg. -30 to +125 deg. 0.3 s 5. Operating Characteristics Tc=25deg.,RL=6ohm(Non-inductive Load),Rg=600ohm,VG=30dB Item Output Power THD Frequency Characteristics Input Impedance O [ ... ]

STK442-110 PDF Datasheet Download