| 摘要 |
PURPOSE:To eliminate influences of a negative feedback constant element of a sound recording amplifier upon reproduced signals at a reproducing time by providing a semiconductor switch between the negative feedback constant element of the sound recording amplifier and the earth and setting this switch to the non-conduction state at the reproducing time to disconnect the negative feedback constant element and a sound and recording and reproducing head circuit from each other. CONSTITUTION:In case of reproducing, a control circuit 11 stops the operation of a sound recording amplifier 2 and sets a semiconductor switch 12 to the non- conduction state to operate a regenerative amplifier 6. Thus, negative feedback constant elements 3 and 4 are disconnected from a signal earth point 10. In this state, the signal reproduced by a head circuit 5 is inputted to the regenerative amplifier 6 and is amplified with characteristics determined by only negative feedback constant elements 7 and 8, and the output signal is inputted to a reproduced signal processing circuit 9. At this time, the operation of the sound recording amplifier 6 is stopped, and therefore, the signal from a sound recording signal generatin circuit 1 is not applied to the sound recording and reproducing head circuit 5. |
