9.6 System Status Indicators
Located on the right hand side of the front panel
are three LEDs. They are used to indicate the
status of the A1 amplifier.
P - Power LED (green) - indicates the A1 ampli-
fier is on and in a ready condition.
S - Standby LED (amber) - indicates the A1
amplifier is in "standby" mode.
F - Fault/Protection LED (red) - indicates the A1
amplifier is in a shutdown condition.
Fault/Protection: The A1 can shutdown in
Protection mode for several reasons. A com-
mon reason is that the speaker output wires
have shorted together. Another could be that
the amplifier has overheated. Should either of
these conditions occur, repairing the cause of
the output short or allowing the amplifier to cool
will solve the problem. To reset the A1, turn the
power switch (rear panel) off and then on. If the
problem persists, contact your NHT dealer.
9.7 Replacing the Fuse
The A1 amplifier's fuse
is user-serviceable.
To replace the fuse:
1. Turn the power off.
2. UNPLUG the power cord.
3. Remove the fuse holder cover (next to
power cord) with a flat blade screwdriver.
4. Remove the fuse from holder and replace
it with the appropriate type.
5. Reinstall fuse holder.
Always replace the fuse with one of the exact
same specifications.
For systems operating at 115VAC, use only a
5x20 mm, T5AL, 250V slow-blow fuse.
For systems operating at 230VAC, use only a
5x20mm, T2.5AL, 250V slow-blow fuse.
9.8 Changing the Line Voltage Setting
The A1 was designed to operate
on two line voltage settings,
115VAC and 230VAC. In the
event that it is necessary to
change the line voltage setting,
begin by turning the power
switch to the off position. Remove all the con-
nections from the amplifier , including the detach-
able power cord. Using a flat blade screwdriver,
slide the switch to the correct position. Use the
115VAC position for 110 to 120 VAC, and the
230VAC position for 220 to 240 VAC. Next you
will likely need a power cord that fits the AC
receptacle and you will need to replace the fuse
(see "Changing the Fuse" above)