| 摘要 |
PURPOSE:To obtain a natural playback sound without its abrupt drop due to adjustment during reproduction, by holding the peak of a signal to be recorded which is passed through a variable resistor at specific intervals of time and attenuating said signal by a specific amount through a variable resistor at specific intervals of time on the bsis of the peak-held value. CONSTITUTION:The signal at a point A after passing through the variable resistor VR is supplied to a peak holding circuit 5, which holds its input peak value in DC-level form. This peak value is A/D-converted by an A/D converter 6 and inputted to a CPU. A comparator 7 perform the dB conversion of the signal from the A/D converter 6 and compares the result with a reference signal of alphadB. If the signal from the A/D converter 6 is denoted as betadB, a computing element 8 calculates (beta-alpha)dB to decide which of switches SW1-SW16 is to be turned on. |
