{TAIL ~ Audio/video device} having {HEAD ~ a volume control function} for an external audio reproduction unit by using volume control buttons of a remote controller and volume control method therefor 
{ TAIL ~ Audio / video device } having { HEAD ~ a volume control function } for an external audio reproduction unit by using volume control buttons of a remote controller and volume control method therefor
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH