Adjustment; Driver Circuit Adjustment; Peak Power Indicator - Sansui AU-G55X Service Manual

2.
ADJUSTMENT
(See
Top View on
page
8)
2-1. Driver Circuit Adjustment
Note:
1)
Master
Volume
....
Minimum
2)
Room
Temperature
...
18°C~28°C
(65°F~83°F)
3)
For
this
adjustment, run the
unit for
more
than 20
minutes
after
the
power
is
switched
ON.
4)
Before turning
ON
power
switch, set
kVRI on
F-4702
to center position.
5)
Before turning
ON
power
switch,
set
kVR2 on
F-4702
fully
counterclockwise.
STEP SUBJECT
MEASURE OUTPUT
ADJUST
ADJUST FOR
REMARKS
1
.
DC
0V
Adj.
L-CH
Speaker Terminal
(L-ch)
kVRI
,
L-ch
(F-4702)
DC 0V±5
mV
2.
DC
0V
Adj.
R-CH Speaker Terminal
(R-ch) kVRI,
R-ch
(F-4702)
DC 0V±5
mV
3.
Bias
Current Adj.
L-CH
Between
emitters of
power
transistors
(kQI
3
&
kQI
4)
(Across kR50L)
kVR2,
L-ch
(F-4702)
DC 10mV±3
mV
4.
Bias
Current
Adj.
R-CH
Between
emitters of
power
transistors
(kQI
3
& kQI
4)
(Across
kR50R)
kVR2,
R-ch
(F-4702)
DC 10mV±3 mV
2-2.
PEAK
POWER
Indicator Level Balance Adjustment
Note:
Before adjustment, turn
nVRl on
F-4705
fully
clockwise from conductor
side.
STEP
SUBJECT SETTING ADJUSTMENT
1
.
PEAK
POWER
Indicator
Level Balance
Adjustment
1.
Feed
1kHz
sine-wave
signal
from audio
oscillator
to
AUX
terminals, L-ch
and
R-ch of the
unit.
2.
Turn
the master
volume
until
the 11th segment
from
the
left
of the L-ch indicator
just
turns on.
I.Turn
nVRl
slowly counterclockwise
until
the
same
segment
of the R-ch
just
turns on.
3