| 摘要 |
PURPOSE:To realize the acoustic equipment which is used for an orchestral accompaniment application by decreasing a level of an audio signal from a music signal reproduced by a reproduction device. CONSTITUTION:The equipment is provided with a 1st amplifier circuit 3 and a 2nd amplifier circuit 9 amplifying respectively left and right channel signals and a level of an audio signal is reduced by applying the signal amplified by the 2nd amplifier circuit 9 to a negative feedback terminal 6 of the 1st amplifier circuit 6 through a band pass filter circuit 24. |
