| 摘要 |
PURPOSE:To supply 4 channel signals used at a Dolby surround system, 4 channel signals in a 3-1 system or 4 channel signals in a 2-2 system to a correspondent speaker while amplifying those signals without changing connection with the speaker. CONSTITUTION:The level control or the like of signals to be amplified is executed by a tone control/master volume circuit 4, L signals, R signals and C signals are supplied to an L channel speaker 16, R channel speaker 17 and C channel speaker 18 while switching first and second selector circuits 1 and 3 corresponding to the objective signals to be amplified, and S signals are respectively supplied to an LB channel speaker 19 and RB channel speaker 20 or L signals, R signals, LB signals and RB signals are respectively supplied to the L channel speaker 16, R channel speaker 17, LB channel speaker 19 and RB channel speaker 20. |
