PURPOSE: To largely assure the dynamic range of a voice signal, of which the input level is not regulated, and to increase the max. attenuation value with a simple constitution in a voice signal recording level adjusting circuit and a voice signal recorder.
CONSTITUTION: A current source section 11 is composed of two stages of multiplier circuits. Differential pairs Q5 and Q6 which are the first stage are controlled by a current rate setting section 12 to set the current ratio of the driving current I1 and I2 to be supplied to an input section 2 and an output section 4. The current source section 14 which is the second stage is controlled by a function current control stage 13 controlled by the current rate setting section 12 and the function current I3 to drive the differential pairs Q5 and Q6 is changed along an exponentialfunctionally changing characteristic curve.
SAKAMOTO ITSUO
OTSUJI ICHIRO
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