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6. DC OFFSET VOLTAGE ALIGNMENT
1.
Before switching the mains switch. Turn down the
master volume to the minimum position and set the
balance volume and tone volumes at the center po-
sitions. Set var iable resistors R627(on the PCB
P601:L ch) and R727(on the PCB P701:R ch) fully
counterclockwise.
2.
Connect the digital voltage meter to the speaker
ter minal. And set the digital voltage meter for the
DC position.
3.
Turn the mains switch ON. Put thin adjustment screw
driver in to the hole of the HDAM (Q601:L ch /
Q701:R ch) copper cover. Adjust variable resis-
tors in the HDAM (Q601:L ch / Q701:R ch) value at
0mV±3mV with in 10 seconds after speaker relay
tur n ON.
7. IDLING CURRENT ALIGNMENT
REMARK
Before “Idling current alignment”,
“ DC offset voltage
alignment “
have to be done!!
1.
Each of cement resistor R641(on the PCB P601:Lch) and
cement resistor R741(on the PCB P701:Rch) are provided
with three test points. Connect the digital voltage meter,
set for the DC voltage input, to the test points at the two
extremities of three test points of R641(L ch) and R741(R
ch).
2.
After the setup above, turn the mains switch ON and
heat up the amplifier about 10 minuetes.
3.
Adjust variable resistors R627(on the PCB P601:L
ch) and R727(on the PCB P701:R ch) according to
the digital volt meter reading. The target setting
value is 9mV±1mV (45mA) for both L ch and R ch.
Alignment
hole
Measurement point
R641 / R741
