| 摘要 |
PURPOSE:To eliminate squeak and to enable excellent communication, by comparing signal energy of each line through a detection a comparison control circuit and making the removal or insertion of a loss circuit based on the result. CONSTITUTION:A detection domparison control circuit 21 compares the signal energy on each line at each time and controls insertion/removal of a variable loss circuit. Through this operation, a loss determined with the number N of branches without fail at the input or output side of each line and the loop gain of 4- line part is constant. For example, an audio signal inputted to an input terminal 1 from a hybrid coil is greater than that of other lines, an input side variable loss circuit 5 and output side variable loss circuits 14, 15-16 are eliminated and input side variable loss circuits 6, 7-8 and output side variable loss circuit 13 are inserted by the circuit 21. Output is made to output terminals 18, 19-20 with 0dB and transmitted via a hybrid coil of other lines. |
