| 摘要 |
PURPOSE: To more independently adjust a compression ratio with single control by making a secondary control signal consist of a combination of a detecting signal and a threshold signal and forming a compression threshold with a threshold controlling signal. CONSTITUTION: A secondary CCA controlling part 706 supplies control current to a secondary CCA 700 and controls gain, and the control current is controlled by an AGC threshold controlling part 710. On the other hand, a detecting signal from an AGC filter 704 passes through an AGC and CR controlling part 712 to enable variable slope compression. The part 712 supplies an adjustable detection signal part to a main CCA controlling part 66, and a controlling part 68 controls the gain of a main CCA 66. Thus, because a gain lowering value which is executed by an input level that exceeds an AGC threshold or an input AGC system to the CCA 66 is changed by the part 712, it changes the slope of an input-output curve that exceeds a threshold. |
