| 摘要 |
PURPOSE:To assuredly prevent the lowering of the reproduced signal, by giving the compensation to the level of reproduction caused by the difference of the shift linear speed of a magnetic head or to the variation of the frequency characteristics. CONSTITUTION:When a turntable rotates, a head attaching table shifts in the radius direction. Accordingly the resistance value of a potentiometer changes. If a resistance 45 is defined as a potentiometer, the gain of an amplifying circuit can be varied by the resistance value of the potentiometer. When a potentiometer is inserted in parllel or in series to the resistance 44 or 45, not only the gain but the frequency characteristics can be controlled. Both the record/reproduction level and the high-range characteristics are lowered at the part of a head where the shift linear speed is low. In this connection, the change of resistanc value is set for the potentiometer in order to increase the degree of amplification to the high-range frequency. |
