| 摘要 |
PURPOSE:To improve an S/N by providing a reproduction amplifier whose amplification degree is controlled by a signal formed by a forming means and generating an output at a fixed level irrespective of the position of a rotating head. CONSTITUTION:An amplification degree characteristic corresponding to surface pressure caused by the head position is given to the reproduction amplifiers 3 and 4. If the amplification degree characteristic shown by graph (b) is given to the reproduction amplifiers 3 and 4, an out-put at a fixed level shown by graph (c) can be obtained from the reproduction amplifiers irrespective of the head position. The outputs of the reproduction amplifiers 3 and 4 are alternately switched in synchronization with a switch pulse through a changeover switch 8. Thus a signal with an excellent S/N can be obtained.
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