A modulation output device including; a DSP 12 for subjecting MP3 music data and the like read out from an MP3 player 50 to stereo modulation, when necessary; D/A converter 14 for converting the digital data outputted from the DSP 12 to an analog signal and outputting the converted analog signal to either an earphone terminal 54 or transmission part 15; and transmission part 15 for transmitting the analog signal outputted from the D/A converter 14 to the outside through a transmission antenna 55 enables the processing concerning reproduction of music data and processing for modulation of the reproduced music data to transmit without wires to be performed by a single DSP 12 and a single D/A converter 14.