Front/Center Amplifier Board; Surround Amplifier Board; Isc Board; Adjustment Points Diagram / Amplifier Adjustment - NAD T 762 Service Manual

ADJUSTMENT POINT DIAGRAM

FRONT/CENTER AMPLIFIER BOARD

R522 R545 R571

SURROUND AMPLIFIER BOARD

R835 R836
P801

ISC BOARD

AMPLIFIER ADJUSTMENT
Idle Current
1. Rotate R522 fully clockwise.
2. Connect DC millivoltmeter to P501 (i.e. Across half of R523, 0.22 Ohm resistor).
3. Turn on the unit.
4. Adjust R522 for 1mV reading on voltmeter.
5. Leave power on for at least 5 min, and check for idle current again.
6. Repeat for other channels.
CHANNEL JUMPER
FL P503
FR P502
C P501
SL P801
SR P802
BS P803
ISC Sensitivity
1. Connect 8 ohm loading to all channels.
2. Rotate R881 fully clockwise.
3. Load all channels at full power using 1kHz sine wave.
4. At this time, monitor the THD of the SL,SR,BS output. Clipping should occur before full power achieved.
5. Rotate R834 counter-clockwise slowly until the THD just below 0.1%.
6. Repeat step 2-5 for R834 but monitor FL, FR & Center output.
7. The procedure is finish at this step.
8. Load all channels at full power using 1kHz sine wave with 4 ohm load.
9. The clipping power(at THD 0.1%) should less than 85W.
P501 P502
R897
P802
R834
VR
R571
R545
R522
R835
R836
R897
P503
P803
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