Datasheet LA4160 (Sanyo) - 6

LA4160
Preamplifier Circuit Since the maximum output voltage for THD = 1% drops at less than 600Ω of the composite load impedance viewed
from output pin (6), it is desirable to make the composite load impedance more than 600Ω when using this IC.
(Refer to VO max, THD – RL characteristics.)
2. ACL Circuit
Preamplifier
input R32
2.2kΩ 9 +
6 Preamp. R35 Meter
R20
10 14
300Ω ALC
OUT R1
3kΩ ALC IN
control
pin R31
300Ω
TR2 VCC 1S 188×2
R33 5 TR1 C5
R34 11 C4 Voltage doubler
rectifier The ALC circuit is of Darlington configuration which consists of TR1, 2. The collector-to-emitter impedance of TR1
made variable by the DC voltage to be applied to control pin (5) and the input voltage of the preamplifier is
controlled. Whe the DC voltage to be applied to pin (5) is set at approximately 1.1V, TR1, 2 are turned ON and ALC
is turned ON. For the rectifier circuit, it is recommended to use the voltage doubler rectifirer which is excellent in
compression ratio. For the sets of 6V VCC, it is recommended to use a germanium diode so that the ALC width can
be made wider even at the time of decreased voltages. No.870-6/11