NAD 3030 - DC Offset Alignment

ALIGNMENT
3 DC OFFSET ALIGN MENT
1. 5 minutes minimum pre-heating is necessary for DC offset adjustment.
2. Set the volume control at minmum position.
3. Speaker switch should be set to “‘main” position.
4. Connect a DC milli-voltmeter to the “main speaker” terminals of each channel. The meter sensitivity should be set
for 100-300mV full scale deflection. The positive input of the meter should be connected to the red (+) speaker
terminal.
. If the readings are within + SOmV, then no adjustment is necessary.
6. If the reading is more than + 50mV then refer to Table I to find the appropriate value resistor to connect from point
A (right) to C (right) on the bottom side (pattern side) of PCB. (see fig. 1 )
B (left) to D (left)
7. If the reading is less than -SOmV then also refer to Table I to find the appropriate value resistor to connect from
point A (left) to E(left) one the bottom side (pattern side) of PCB. (see fig. 1 )
B (right) to F (right)
8. Use a piece of insulating sleeve on the resistor legs to avoid shorting to PC board tracks, and make sure the resistor
is not pressed against a sharp cut edge of a component leg.
* Important notice: The power button must be in the off position when soldering is done.
an
Table I
Reading of DC Milli Voltmeter *Resistor
50 to 60 mV 100k ohm OR 330k ohm
60 to 75 mV 82k ohm OR 270k ohm
75 to 90 mV 68k ohm OR 220k ohm
90 to 110 mV 56k ohm OR 180k ohm
110 to 135 mV 47k ohm OR 150k ohm
135 to 165 mV 39k ohm OR 120k ohm
165 to 200 mV 33k ohm OR 100k ohm
to mV ohm OR ohm
9. After having soldered in the resistor, repeat steps 1 through 5.
* If the feedback resistors of power amplifier (R 613, R614) are 10 kohm then select from colum A if 33 kohm then
select from colum B.