NAD 7225PE - Page 2

MAIN AMPLIFIER ADJUSTMENT
IMPORTANT NOTES: .
1) Before adjusting, remove input signal and load, and set Speaker impedance switch to 8 ohms (reset to 4 ohms when finished).
2) These. adjustments are always necessary after repair to main amplifier.
3) After repair, it is recommended to use current limiter (30-70W lightbulb) in mains fine, for initial turn-on.
A. CENTER VOLTAGE ADJUSTMENT
1. Connect DMM across L channel (R channel) output terminals.
2. Turn on, and adjust R-411 (R-412) for reading of OV + 30 mVDC.
B. IDLE CURRENT ADJUSTMENT
Remove solder short across R-455 and R-456.
Connect DMM across P-403(—) and P-404 (+).
Turn on and adjust R-443 for reading of 28 mV +2 mVDC.
Repeat, using P-405(+) and P-406(—), adjust R-444.
BOM
C. FINAL ADJUSTMENT
1. Leave power on for a minimum of 5 minutes with no signal connected.
2. Repeat center voltage and idle current adjustments.
3. WHEN FINISHED, REPLACE SOLDER SHORT ACROSS R-455 AND A-456.
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