Audio Controller Integrated Circuits - HK725

 Audio volume controller IC .
 Built 2 channels in IC body, 
   sound volume attenuation 
   control by UP / DOWN key .
 0 dB ~ 66 dB changing with 2
   dB attenuation each step .
 Both of dual power suppliers
   of ( + ) and ( - ) or single power
   supply can be used .