Hi! You know that wires are coming out from mp3 player's 3.5mm jack to the two speakers of the stereo earphone. I want cut that wire of the earphone and take wires to input to a FM modulator as the modulating (message) signal. Is this possible? Simply I want to do something similar done here to test a FM transmitter. http://people.virginia.edu/~ll2bf/docs/various/fm_xmtr.html I want to do it just by using the earphone connected to the mp3 player. And how I identify the wires (ground, left, right) properly and how I make the stereo signal to a mono signal?