| 摘要 |
PURPOSE:To obtain a sufficient characteristics without saturation at high frequencies even if a device whose tape speed drives slow is used, by separating an input signal for encoding or decoding into a signal for a main signal system and a side chain signal system. CONSTITUTION:In the encoding state where a switch S11 to the position of contact (a), a signal applied to an input terminal IN is separated into a signal for the main signal system introducing the applied signal to an adder 22 as it is via an amplifier 21, and a side chain signal system introducing the applied signal to an adder 22 via an amplifier 23, a filter circuit 24 and a variable impedance circuit 25. The filter characteristics is changed by controlling the impedance of the variable impedance circuit 25 with a control voltage formed from an output of the circuit 22 via an amplifier 26 and a detecting circuit 27. In the decoding state where the switch SW11 turns to the position of contact (b), a signal having the decoding characteristics is derivered with almost reverse procedures as those at the encoding. |
