| 摘要 |
PURPOSE:To attain ease of positioning for balance by making control voltage of right/left channels to be applied to a variable gain amplifier equal to each other within a range being symmetrical to the right and left around the balance central position. CONSTITUTION:A balance control voltage VBAL divided by a variable resistor 3 is converted into a current IBAL by a V/I converting circuit 6 so as to drive a current mirror circuit 11 comprising transistors (TR)8, 9, 10. Further, reference voltages Vref(L), Vref(R) divided by resistors 4a, 4b, 5b, 5a are converted respectively into currents Iref(L) and Iref(R) by V/I converting circuits 7a, 7b to drive current mirror circuits 15a, 15b, thereby allowing current mirror circuits 20, 25 to operate the currents and to generate currents IB-L, IB-R, voltages VB-L, VB-R. |
