6
CX233 I
NSTALLATION AND OPERATION MANUAL
6.02
Fitting of DC to DC power supply
1.
Disconnect the CX233 from the mains power
2.
Remove the top and bottom panels
3.
Fit the two spade terminals on to the PCB. It is clearly marked Red+ve, Black-ve.
Then solder them in place
4.
Fit the fuse holder to the PCB in the location marked F1. Solder this in place then
fit the T800mA fuse.
5.
Fit the NMXD2415 to the pcb, then solder in place.
6
All the soldered joints should be cut flush with the joint.
7.
Remove the cover positioned over the 4 pin XLR mounting hole.
8.
Fit the 4 pin XLR connector using the screws provided. Connect the red and
black wires to the appropriate terminal on the PCB.
9.
Re-fit the top and bottom panels.
7
Fire Alarm Interface (Remote Music Mute)
In certain circumstances, there may be a local authority or fire service requirement to
mute the music signals via a fire alarm control panel in an alarm condition. The CX233
provides a facility to attenuate or fully mute the music signals only, by using a fully floating
pair of contacts in the control panel which would need to be closed during an alarm
condition.
In the remote music mute mode both microphone signals are automatically routed to all
zone outputs bypassing any front panel switches, zone level controls and VCA controls.
In addition to this all music signals are attenuated by 20dB or muted, dependant on the
setting of the internal jumper.
It should be noted that in order to avoid a panic situation, the muting takes place
gradually, over approximately 10 seconds. The recovery is also subject to a similar
delay.
8
Mic 2 Emergency Mode
The Mic 2 input can be used for evacuation purposes by switching to the "emergency
mode". In this mode, the Mic 2 input would be muted when the CX233 is working
normally. When the fire alarm is activated, all music signals are muted/attenuated and
both Mic signals are routed to all outputs as above in section 7.10. In addition to this the
front panel level control for Mic 2 is rendered inoperative, instead a PCB mounted preset
controls the level of Mic 2. The rear panel gain control remains active under these
conditions. This emergency mode is intended to allow Mic 2 to be used for a dedicated
evacuation Mic or evacuation message player.
9
Earthing
The 0v rail on the CX233 is connected to the mains earth and the mixer/zoner must
always be earthed. If any mains powered signal source has its own earth, then earth loop
hums may cause problems. The "hum" can be remedied in several ways. The preferred
method is to operate all inputs and outputs in the balanced mode, with the cable screen
only connected at the receiving end. Alternatively, re-route the mains supply of the
apparatus to the same point as that of the CX233. (Note: Microphone cables must be
earthed at both ends).
