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