Headphone circuit based on field effect transistor as silencer

　　The figure above shows a headphone circuit using a field effect transistor as a silencer . The L and R audio signals from the digital signal processing circuit are sent to the headphone interface through the silencer control circuit. The drains of the Ql and Q2 field effect transistors are respectively connected to the input lines of the L and R signals. When the control circuit sends the silencer control voltage , Ql and Q2 are turned on, short-circuiting the L and R signals to ground, no signal is output, and the MP3/MP4 player is in a silenced state.