| 摘要 |
PURPOSE:To eliminate mis-classification of an ALC characteristic due to temperature change in the lapse of time by forming a reference sample of an automatic level control ALC control input voltage and testing it at the same time together with a sample to be classified. CONSTITUTION:Recording amplifiers A, A' with an ALC circuit have the same function and same value. Components represented in the same numeral between the reference sample A and the measured sample A' have the same function and same values. An ALC control input voltage when a switch S is thrown to a contact (a), i.e., the position of the reference sample A and an ALC control input voltage when the S is thrown to the position of a contact (b), i.e., the position of the measured sample A' are compared. In classifying the sample according to the difference of the control input voltage of the sample to be classified to the reference sample, the sample having a desired ALC characteristic used in a stereo player is obtained. The generating mechanism of the ALC control input voltage is entirely the same as that of a conventional method. |
