Audio output distortion
Check the audio quality of the original MP3 file.
Ensure that file frequency and bit-rate do not exceed 44KHz and 128Kbps. The optimum MP3 file parameters are; Mono at 44 KHz (44100 Hz) Sample Rate, 128k Bit-Rate (kbps)
Ensure that RCA connections on both your Sonorous CD unit and your output device are secure and not damaged.