C l e a r l y b e t t e r s o u n d
Cloud Electronics Limited
140 Staniforth Road, Sheffield, S9 3HF. England. Telephone: +44 (0)114 244 7051 Fax: +44 (0)114 242 5462 Web: www.cloud.co.uk Email: info@cloud.co.uk
The Cloud CX-A450 and CX-A850 are high-quality multi-
channel power amplifiers designed for relatively low-power sound
reinforcement applications in commercial or industrial premises.
They are ideal for situations where the various locations of the
building require different programme material and/or levels.
The two models are:
MODEL
POWER
CX-A450
4 x 50 W
CX-A850
8 x 50 W
The amplifiers will deliver their rated power into 4 ohm loads for
long periods of time. Safety features of the design include Cloud’s
Dynamic Clipping Protection circuitry, VI limiting, switch-on delay
(5 seconds) and protection against DC offset or thermal overload.
Both models are built in a 2U steel enclosure, and use variable–
speed forced-air cooling.
Any two channels may be wired in Bridge Mode, allowing power
outputs of double the normal rating to be delivered to a load of
8 ohms (minimum).
In addition to the power switch and associated LED, the front panel is
fitted with three LEDs for each channel, confirming signal presence,
peak level and activation of the protection circuitry. Rear panel
controls are provided for individual channel gain trims and input
routing to configure the amplifier in various combinations of mono,
stereo or multi-channel operation. The inputs are electronically
balanced.
The CX-A450 and CX-A850 may also be used with 100 V/70 V-line
loudspeaker systems by the addition of standard Cloud accessories.
The CXL-4160 is a four channel transformer module which can
be internally fitted to the CX-A450, while the CXL-40T is a single
channel toroidal transformer module for external mounting. For
installation convenience, the CXL-800, a 2U rackmounting assembly
which can hold up to eight CXL-40s, is also available. To prevent LF
transformer saturation in 100 V/70 V-line systems, a 65 Hz high-pass
filter may be enabled for each channel individually, by internal jumper.
Other standard options are Cloud RL-1 remote volume control
plates, the VCA-5 single-channel VCA card (required for level
control by RL-1), and EQ cards to suit various makes and models of
loudspeakers. Remote level control or speaker EQ may be fitted to
any or all channels.
Cloud CX-A450 - front panel view
Cloud CX-A850 - front panel view
CX-A450
FOUR CHANNEL POWER AMPLIFIER
PROTECT
PEAK
SIGNAL
POWER
4
3
2
1
EIGHT CHANNEL POWER AMPLIFIER
CX-A
850
1
2
3
4
5
6
7
8
PROTECT
PEAK
SIGNAL
POWER
CH 1
REMOTE
LEVEL
1
2
3
RL-1
1
2
3
CH 2
REMOTE
LEVEL
RL-1
2
1
3
3
2
1
CH 3
REMOTE
LEVEL
RL-1
2
1
3
3
2
1
CH 4
REMOTE
LEVEL
RL-1
2
1
3
3
2
1
1
3
2
1
LEVEL
2
3
2
1
LEVEL
3
3
2
1
LEVEL
4
3
2
1
LEVEL
POWER INPUT
FUSE
REPLACE FUSE
WITH SAME TYPE
AND RATING
230V - 3.15A H
115V - 6.3A H
THIS PRODUCT MUST BE EARTHED
40-60Hz
5%
V
SPEAKER OUTPUTS
MINIMUM LOAD 4OHMS
OUTPUT RATING 50W/4OHMS
100V/70V LINE
OUTPUTS
CH1
CH2
CH3
CH4
1
2
1
2
3
4
(OUT)
(IN)
(IN)
(OUT)
(IN)
(OUT)
CH1
0V
0V
CH2
0V
CH3
0V
CH4
SOURCE
SOURCE
SOURCE
HIGH VOLTAGE
THIS COVER
REMOVE
DO NOT
OUTPUT
DANGER
LINE
100V/70V
REMOTE
LEVEL
REMOTE
LEVEL
REMOTE
LEVEL
REMOTE
LEVEL
REMOTE
LEVEL
REMOTE
LEVEL
REMOTE
LEVEL
REMOTE
LEVEL
FUSE
230V - T4A
115V - T8A
CH 1
RL-1
1
2
3
1
2
3
1
2
3
RL-1
2
3
1
1
2
3
RL-1
2
3
1
1
2
3
RL-1
2
3
1
1
2
3
RL-1
2
3
1
1
2
3
RL-1
2
3
1
1
2
3
RL-1
2
3
1
1
2
3
RL-1
2
3
1
CH
CH
CH
CH
CH
CH
CH
2
3
4
5
6
7
8
1
2
1 2 3
LEVEL
SOURCE
- --
2
(OUT)
(IN)
(OUT)
1
(IN)
3
3
SOURCE
LEVEL
1 2 3
--
-
(OUT)
2
(IN)
4
4
SOURCE
LEVEL
1 2 3
--
-
(OUT)
1
(IN)
5
5
SOURCE
LEVEL
1 2 3
--
-
(OUT)
2
(IN)
6
6
SOURCE
LEVEL
1 2 3
--
-
(OUT)
1
(IN)
7
7
SOURCE
LEVEL
1 2 3
--
-
(OUT)
2
(IN)
8
8
SOURCE
LEVEL
1 2 3
--
-
LEVEL
1 2 3
--
-
1
SPEAKER OUTPUTS
OUTPUT RATING 50W / 4OHMS
MIN LOAD 4 OHMS
0V
CH1
0V
CH2
0V
CH3
0V
CH4
0V
CH5
0V
CH6
0V
CH7
0V
CH8
POWER INPUT
REPLACE FUSE WITH SAME
TYPE AND RATING
THIS UNIT MUST BE EARTHED
5%
40-60Hz
CLOUD MULTI-CHANNEL POWER AMPLIFIERS
MODELS CX-A450 & CX-A850
Cloud CX-A450 - rear panel view
Cloud CX-A850 - rear panel view
General Description
