| 摘要 |
PURPOSE:To obtain excellent sound quality whose high frequency range is expanded without inhibiting the passage of the high frequency range by providing a pitch changer circuit which varies an interval in an acoustic circuit and also providing a filter which is variable in passing frequency with an operation signal applied thereto. CONSTITUTION:When a signal is sent to the pitch changer circuit 5, the signal is sent to low-pass filters 2 and 7 from a CPU 9 by signal lines 12 and 13, so the filters 2 and 7 vary in cutoff frequency according to the kind of the signal, i.e., whether the circuit 5 increases or decreases the pitch. The cutoff frequencies of the filters 2 and 7 increase as the circuit 5 increases the pitch, so when the pitch is increased only by one or two, the frequency range is not cut off by the filters 2 and 7 although the frequency range is expanded up to about 15KHz, thereby obtaining superior sound quality in the high frequency range. |
