A-A9-J
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6. ADJUSTMENT
6.1 Idle Current and DC offset Adjustment
1. Idle Current Adjustment
• Measurement Points:
AMP Lch Assy : R729
AMP Rch Assy : R774
•
Adjustment
Points:
AMP Lch Assy : VR702
AMP Rch Assy : VR703
• Procedure
1
Turn on the power
2
Connect a digital voltmeter to both ends of resistor of the measurement point.
(70 mV of AMP Lch: R729 and AMP Rch: R774).
3
Perform aging for more than five minute.
4
Slowly turn the adjustment VR clockwise so that the voltage becomes in the
readjustment of 60 mV
• Adjustment Point and Measurement Points
.... see fig1.
DC offset
VR: VR704
Idle current
VR: VR703
AMP Lch Assy
AMP Rch Assy
[fig 1.]
+
8
Ω
Speaker dummy connection.
8
Ω
Speaker dummy connection.
+
2. DC Offset Adjustment
• Measurement Points:
AMP Lch Assy : SP terminal
AMP Rch Assy : SP terminal
•
Adjustment
Points:
AMP Lch Assy : VR701
AMP Rch Assy : VR704
• Procedure
1
The voltage of SP terminal is adjusted to 0
±
10 mV.
(8
Ω
Speaker dummy connection)
• Adjustment Point and Measurement Points
.... see fig1.
Idle -TP
R774
Caution when transistors (Q713, Q714, Q739 and Q746) are replaced
Please cover the leads of the transistors at Silicon bond for the variation prevention
of DC Offset when you have exchanged transistors.
Q714
Q713
Q746
Q739
Refer to below
in exchange
I
J
www. xiaoyu163. com
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