| 摘要 |
PURPOSE:To handle a stereophonic broadcast and a bilingual broadcast, by equalizing the levels of the sum and difference signals of the left and right sound signals of the stereophonic broadcast to those of the main and subsignals of the bilingual broadcast. CONSTITUTION:The left and right sound signals of a stereophonic broadcast and the main and sub sound signals of a bilingual broadcast are inputted through sound signal input terminals INA and INB to gain adjusting circuits 1a and 1b, whose outputs are controlled by switching circuits 2a and 2b under commands from control signal terminals INC and IND. To the differential amplifying circuit 3 consisting of differential couples of transistors T7 and T9, T10, and T11, T15' and T17, T18 and T19, T16 and T20 and T21 and T22, the left and right sound signals, and main and sub sound signals from the circuits 1a and 1b, and control command signals from the terminals INC and IND are inputted, so that the sum and difference signals and main and sub sound signals of the left and right sound signals appear at terminals OUTA and OUTB. |
