| 摘要 |
PURPOSE:To simplify the constitution and to obtain an ultralow tone sound with high sound quality immune to noise by controlling a resonance level and a resonance frequency of a signal simply with a DC voltage. CONSTITUTION:A signal S1 inputted to an input terminal 1 is branched into two by a branch means 4 and a 1st output S2 is inputted to a resonance circuit 2 having a resonance point at a low sound frequency. Then a resistance, for example, is controlled by a DC voltage either or both of a resonance level and a resonance frequency of the resonance circuit 2 is controlled by a DC control circuit 3 and a signal S4 whose low sound frequency is emphasized. Thus, an ultralow sound with high sound quality is obtained with immunity to noise and simple constitution. |
