Crest Audio WMA 4300, Owner'S Manual

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11
Color:
Black
Architectural and Engineering Specifications
The wall mount mixer/amplifier shall have 4 electronically balanced mic/line inputs. The front panel shall include four input
level controls, a master output level control and power switch. The gain of the input preamps shall be continuously variable.
Front panel indicators shall include channel signal, clip and priority mute condition, power on, signal presence at the amplifier,
ACL ™ status and master mute status. It shall have an internal power amplifier with a rated output of 300 Watts. There shall be
four inputs with Euro-type connectors for the balanced input connections. Channel 4 shall have a switch to select between the
balanced input or dual summing RCA connectors. The mixer shall have switches to apply 48 Volt phantom power to Input 1 and
to inputs 2 and 3. An electronically balanced output with a Euro-type connector and a separate level control shall be provided
with a switch to select between the mixer output or channel 4 input signal. Channel 1 shall have a continuously variable mute
threshold control. Setting this control fully clockwise shall defeat the Channel 1 mute function. The mute threshold sensitivity
for Channel 1 shall be increased as the control is turned clockwise. When the signal level in Channel 1 exceeds the mute
threshold, Channels 2-4 shall be muted. The master section shall include bass and treble EQ controls, each with a ±10 dB range
of operation. The unit shall have a line voltage selector switch for operation at 100 - 120 VAC or 220 - 240 V 50/60 Hz. The
mixer amplifier shall have a direct 4 Ohm output, and 3 transformer outputs – 100 Volt, 70 Volt, and 25 Volt. The amplifier shall
include clipping protection via ACL ™ . The unit shall be 14.25”W x 19.0”H x 4.85”D (362mm x 483mm x 123mm) without
surface mount trim and 15.76”W x 20.56”H x 4.85”D (400mm x 522mm x 123mm) with surface mount trim installed. The
back box shall have knock-outs for 1/2” or 16mm conduit. The unit shall be called the Crest Audio Professional Installation
Series Power Amplifier model WMA 4300.
Appendix
UPDATING A WMA 75/150 WITH A WMA4300 CHASSIS
The WMA 75 and WMA 150 can be updated with a WMA 4300 chassis using the existing back box and cover. The WMA4300 is
smaller than the other units, so some modifications to the original back box must be done to secure the new chassis in it.
1.
Make sure that the power feeding the WMA 75/150 has been shut off before any operations are done.
2. Remove the cover from the existing WMA 75/150. Set the cover aside, it will be reinstalled later.
3. Disconnect any input and output connections to the chassis sub-assembly. Remove the main chassis. It will be replaced
by the WMA4300 chassis.
4. The top hinge piece of the back box must be relocated to match the position of the one on the WMA 4300 chassis. An
easy way to drill the holes is to remove the top hinge from the back box, fit this onto the mating hinge of the WMA4300
chassis and use it as a template to drill the holes. Drill three 7/64 inch diameter holes for #6 thread-forming screws, and
attach to the back box in its new position.
5. Remove the two 1.0” stand-offs at the top of the WMA 4300 chassis and attach them to the flat metal bracket provided.
These will be used to mount the old cover to the new chassis.
6. Slide the WMA 4300 chassis onto the hinges.
7. Mount the bracket to the wall box using the top two screw holes of the removed hinge and the single unused chassis
mount insert on the other side.
8. Connect power, input, and output cables. The connectors will have to change to match what is on the new unit. Euro
connectors are provided with the WMA 4300.
9. After gains and other functions are adjusted and set, install the original cover that was set aside.