| 摘要 |
PURPOSE:To prevent a noise generated due to a BBD securely when no music signal is present by mixing an echoed voice signal with a music signal only when the music signal is present. CONSTITUTION:The music signal from a head 1 during a tape run is applied to a mixing circuit 4 through a signal path 2 and also supplied to a detecting circuit 15 at the same time. In response to the output of the circuit 15, a cutting-off circuit 16 does not operate on a signal path 8 and the voice signal from a microphone 5 is applied to a mixing circuit 11 through a signal path 7 and also through a signal path 8 with the BBD8. Therefore, the speaker 14 outputs the mixed signal of the music signal and echoed voice signal. On the other hand, when the tape is stopped, the output of the signal path 8 is grounded to prevent a noise due to the BBD9. |
