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ALIGNMENT
METHOD
AUDIO SECTION 7220PE
IMPORTANT
Speaker Impedance switch should be in 8 ohm position while adjusting center volatge and idling current.
INITIAL
ADJUSTMENT
(No
load
connected)
A.
CENTER
VOLTAGE
1, Connect DC millivoltmeter to L channe) output terminals.
2. Turn on and adjust to 0 ¥ +- 30mV with VR411 (100 ohm).
7
Connect DC millivoltmeter to R channel output terminals and adjust VR412 to 0 V +- 30mv.
B.
IDLING
CURRENT
1. Remove solder short across R455 and R456.
2. Connect DC millvoltmeter across P403,P404 (output transistor's collector resistor) and adjust R443
for 26-30mY reading on meter.
Repeat adjust with R444, connecting meter across P405,P406.
3. Leave power on for minimum 5 minutes.
FINAL
ADJUSTMENT
C.
CENTER
VOLTAGE
1. Repeat step A above.
D.
IDLING
CURRENT
1. Repeat step B and adjust with R443, Rd for 30mV reading on meter.
2. After the alignment is finished, 1 ohm resistor R455,R456 is shorted by solder short.
mo
CENTER
VOLTAGE ADJ
RAa3
fOLING CURRENT Ao)
Mace
IDLING
CURRENT ADJ
REZ
CENTER VOLTAGE AD}
AMPLIFIER
ADJUSTMENT
POINTS
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5 --
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