Before operating the unit, please read these instructions thoroughly and retain them for future reference: Speaker(s) Operating Instructions: To play auxiliary sources (cd, MP3 Player, computer etc...) through the speakers, plug the unit's input line (found inside the zippered speaker compartment) into the earphone jack of your CD, MP3 player or computer and switch the AM/FM/AUX switch to AUX. Then turn the power on with the “power/vol” knob and adjust volume accordingly.