Mixer On/Off
This switch turns the internal mixer On or Off.
When the Mic or Line/CD inputs are used, this
switch must be set to the On position. If these
inputs are not being used, the mixer should
be turned Off. This will help prevent the mixer
from loading the Link, or the Internal Mixer, and
contributing noise to the system. The internal
mixer should not be used when a source
other than another NX550P or similar cabinet
is connected to the LINK jacks. Remember, a
maximum of three mixers, in a chain of cabinets,
should be used! A much larger number of
cabinets may be used with the NX550P mixers
disabled on the additional cabinets.
Mic Control
This control adjusts the volume level the Mic
input. The microphone signal output to other
cabinets through the link connections will be
affected as well.
Line/CD Control
This control adjusts the volume level of devices
plugged into the Line/CD input. The signal out
to other cabinets, from this device, through
the link connections will be affected as well.
A line-level signal and microphones can be
connected simulataneously.
Treble and Bass Controls
These controls affect the signals from devices
plugged into the Line/CD and Mic inputs. The
signal out, to other cabinets, through the Link
will also be affected. These controls do not
affect signals coming into the cabinet from
the Link connections.
Green PWR LED
Illumination indicates that AC power is on and
the fuse is functioning.
Yellow Limit LED
This indicates that the cabinet is operating
at full power and the limiter(s) are actively
reducing the signal level. It’s all right to
operate in limiting as long as the clip light is not
constantly on. The Limit light does not indicate
low frequency processing action. There are
separate limiters for the woofer and horn. This
LED will indicate operation of either limiter.
Red Clip LED
The illumination of this LED indicates that
the signal level is excessive and may cause
distortion. Reduce mixer levels or turn down the
Level control (on NX550P) to reduce clipping.
POWER Switch
This turns the power On and Off to the
cabinet. Note; a cabinet that is turned off,
but is one of the cabinets in a chain might
cause hum (or buzz) in the other cabinets.
Fuse
The mains fuse should never blow even in
extreme operating conditions. A blown fuse will
generally mean that excessive mains voltage
has been applied or there’s a serious fault with
the unit. Self re-setting thermal switches are
built into the power transformer as well as on
the internal heat sink. These will not trip even
under the most extreme operating conditions
and are provided only for safety reasons.
Thermal margins may be compromised when
operating facing straight up, straight down or
while operating in direct sunlight!
A note about unbalanced operation:
When connecting an unbalanced source
(such as a mixer with RCA outputs) to
balanced inputs such as an NX550P, the
best hum rejection can be achieved by
running a balanced connection right to the
unbalanced plug. The return connection
should be connected to ground at the
unbalanced plug. The NX550P does not
connect the AC power ground directly to
the input signal ground. This will eliminate
most ground problems.
