Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Harman Kardon receivers have superb sound

Speakers and source components (CD player, Tape Deck, Turntable) will have the greatest impact on the sound quality of your HiFi, but the receiver is also important. Harman Kardon receivers incorporate a number of innovative circuit designs that significantly improve the sound quality of the receiver and the rest of your system. My father had been using another name brand receiver for a number of years and had been quite happy with it, but it eventually conked out. We replaced it with a Harman Kardon receiver and were both struck by how much better his whole HiFi sounded and the receiver was the only component we'd replaced. Harman Kardon costs more than the run of the mill receiver, but they are well worth it.