| 摘要 |
PURPOSE:To attenuate noise level at the time of silence, by controlling an amplifier's gain by use of a reverse characteristic output signal for reproducing level of a tape recorder which is provided with an automatic recording level controlling circuit. CONSTITUTION:At the time of recording, if a recording switch is turned to the R side, an input signal from a mike 10 is automatically adjusted in accordance with its input level and is recorded on a tape through a recording head 18 together with a bias current from a bias oscillator 20. At the time of reproducing, if the switch is turned to the P side, an output of the reproducing head 18 is inputted to an AC amplifier circuit 30. When the output of the amplifier circuit is inputted to a base of PNP transistor 42, a current between an emitter and collector of the transistor flows to obtain a reverse characteristics in which AGC voltage VALC becomes larger as the signal is smaller and adjusts a gain of a preamplifier 12 by the control signal. |
