| 摘要 |
PURPOSE:To easily control a cut-off frequency and an output level by a digital signal by using a semiconductor switch without any mechanical contact point, a semiconductor variable resistor without any mechanical slider and an arithmetic unit such as a microcomputer. CONSTITUTION:The cut-off frequency of a sound signal impressed to a signal input terminal 13 is decided by controlling a semiconductor switch provided in a band-pass active filter 11 via the 1st control data latch 15 through the use of a cut-off frequency control data in N-bit being the decoding of a value set by a control key 18 setting the cut-off frequency and the output level at an internal arithmetic unit 17. The input signal controlled at the cut-off frequency selected by the semiconductor switch is impressed to an output level adjusting device 12 of the next stage, the output level of the input signal is controlled by the semiconductor variable resistor of the output level adjusting device 12 via the 2nd control data latch 16 with an N-bit output level control data from the unit 17 and a processed sound signal is outputted from a signal output terminal 14. |
