| 摘要 |
PURPOSE:To prevent deterioration of crosstalk due to the current of a feedback circuit by connecting the input of a voltage follower to the earth for an input signal, and determining the reference voltage of the feedback circuit on the basis of the output of the voltage follower. CONSTITUTION:When a right channel input terminal 2 is short-circuited and a signal is inputted to only a left input terminal 1, currents flowing through feedback resistances 7 and 5 flow to the output of the voltage follower 23 as shown by an arrow (e) at the time of oscillations of the output of an amplifier 9 and then flow to the power source of the voltage follower. Then, the input of the voltage follower 23 is connected to an input signal earth line, so the output potential of the voltage follower 23 becomes equal to the potential of the input signal earth line and the current of the feedback circuit does not flow to the earth line. Consequently, there is no potential difference between points (c) and (d) by the current of the feedback circuit and no signal leaks to a right channel. |
