Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Apparantly commonly defective

I purchased a RioVolt SP-50 today and promptly returned it. I played several MP3 CD's and consistantly had the same audio problem: an occasional "chirp" (for lack of a better description) coming through primarily the right channel. I then tested several MP3 CD's with the same material in the SP-50 and other CD players. The SP-50 was the only one that displayed that defect. ... The Rio, save the audio glitch, was a little louder and less noisy. ...