Advertisement
Drive Amp. (TXX- 373)
Center Voltage
Adjustment
6-(1)
Drive Amp. Center Voltage
Adjustment
1. Before turning on the power, set the semi-fixed resistors
(R311
for Left channel and R312 for Right channel) of
the drive amplifier circuit board (TXX-373) to the center
position.
. Adjust the semi-fixed resistors (R311 and R312) so that
the voltage at the following test points of the power
amplifier circuit board (TXX-374)
is within a range of
+10OmV or less five minutes after the power is turned
on.
and test point @® (ground).
The
measurements
can
also
be
performed
at
the
speaker terminals if the relay is operating normally.
A-X55
No, 2589
Power Amp. (TXX-374)
@
@
Right Channel
Left Channel
Right Channel
Test Point
©
@
(@)rs2i
Left
Channel
Idling Current
Adjustment
Fig. 8
channel)
of the
power
amplifier
circuit
board
fully
counterclockwise.
. Adjust the semi-fixed resistors (R521 and R522) so that-
the voltage at the following test points of the power
amplifier circuit board is within a range of 9MV ~ 13mV
after the power is turned on.
Left channel:
Measure
the
voltage
between
test
point
@
(emitter of 0523) and output
at the test point
Right channel:Measure
the
voltage
between
test
point @) (emitter of Q524) and output
at the test point
. Readjust resistors R521
and R522 about five minutes
after the power is turned on (the heat-sink temperature
must be sufficiently high) so that the voltage at the test
points becomes
11mV.
Confirm that the voltage does
not vary when the heat-sink temperature increases fur-
ther.
Note:
Be sure to perform the measurement
with the
probes
and
cabinet
of
the
measuring
equipment
separated from the grounding terminals of A-X55 or of
other measuring equipment.
= 6A
_ TXX-376-4
> some
YKC43HB
°
oO
i
He
x
x
z
WY
Advertisement
