| 摘要 |
PURPOSE:To eliminate the noises of a magnetic tape, by reading out the tape noises through a head when the sound recording is carried out and then recording the read-out noise component in conforming with the original signal in an adverse phase. CONSTITUTION:A main signal and a bias signal (m) is looped with a coupling transformer T, etc. through a microphone M, preamplifiers AMP1 and AMP2, a main amplifier AMP3, etc. A tape noise eliminating signal (k) which is read out to a differential amplifier AMP5 via a sample control signal (h) passed through an impedance balancer L, a balance signal (i) supplied to the AMP5 from a bias oscillator O, a tape noise reading-out signal (j), etc. and then amplified by an amplifier AMP6 is injected to a main recording signal in an adverse phase. In such a way, the noise of a magnetic tape can be eliminated. |
