Power Amplifier Adjustment; Idling Current Alignment - Marantz SR7300 Service Manual

11. POWER AMPLIFIER ADJUSTMENT

Idling Current Alignment

1. Each of the measurement points are provided with the two test points. Set a digital Voltage meter to DC voltage input,
connect the meter to the test points at both contact points.
2. After the setup above, turn on the main switch and heat up the amplifi er about 10 minutes.
3. Adjust variable resistors (R137, R138...R338) according to the digital voltmeter readings. The target setting value is 4.9
mV +/- 0.05 mV for each channels.
Settings : Master Volume --- Minimum
Speaker out --- No Load
Top lid --- OPEN
Alignment
Channel
Front L R137
Center R337
Front R R273
Surr. L R138
Surr. R R238
SB R338
Time Table of Idling Current Rise
After Turning ON
5 min.
10 min.
20 min.
30 min.
40 min.
60 min.
Measurement
Point Point
J107
J106
J103
J105
J108
J104
Measurement Voltage
(R***)
4.5 mV
4.9 mV
5.5 mV
6.2 mV
6.8 mV
7.0 mV
55