| 摘要 |
PURPOSE:To expand a dynamic range, by continuously varying a recording bias quantity and the encoding characteristics of noise reduction in accordance with a variation of a frequency spectrum and a level of an input signal. CONSTITUTION:When a switch 7 has been set to off, this tape recorder executes the same operation as a well-known tape recorder provided with a noise reduction circuit. Subsequently, when the switch 7 is set to on, an input signal is supplied to a high pass filter 3 its high band component is inputted to a level detector 4, and when the high band component contained in the input signal increases, a control signal appears in an output of the level detector. In accordance with this control signal, a bias controlling citcuit 5 varies a recording bias quantity in the direction decreasing from a reference value, also an equalizer controlling circuit 6 varies the characteristics of an encoder 2 in the direction decreasing from the reference characteristics, and controls so as to weeken high band emphasis of the signal. |
