Cloud Electronics VTX4400 User Manual
Page 8
VTX Series User Manual v1.0
8
The three switches on the rear of VTX amplifiers allow a total of 8 routing possibilities, including 4-channel, dual stereo and
mono operation with 4 channels paralleled. The table below clarifies the options:
AMPLIFIER
CONFIGURATION
BUTTON POSITION
INPUT ROUTING:
AMPLIFIER CHANNELS FED BY EACH INPUT
CH 2
CH 3
CH 4
IN 1
IN 2
IN 3
IN 4
4-channel
IN
IN
IN
CH 1
CH 2
CH 3
CH 4
Dual mono + stereo
OUT
IN
IN
CHS 1 & 2
CH 3
CH 4
Dual mono + stereo
IN
OUT
IN
CHS 1 & 3
CH 2
CH 4
Treble mono + 1
OUT
OUT
IN
CHS 1, 2 & 3
CH 4
Dual mono + stereo
IN
IN
OUT
CH 1
CHS 2 & 4
CH 3
Treble mono + 1
OUT
IN
OUT
CHS 1, 2 & 4
CH 3
Dual stereo
IN
OUT
OUT
CHS 1 & 3
CHS 2 & 4
Quad mono
OUT
OUT
OUT
CHS 1, 2, 3 & 4
Remote Control of Level
VTX amplifiers are compatible with standard Cloud remote
control plates Type RL-1, allowing control of level from a
remote position. RL-1s may be connected at the rear 3-pin,
5 mm-pitch screw terminal connectors (REMOTE LEVEL),
using the wiring shown below.
Use two-core screened cable to connect the remote level
plate (maximum length 100 metres).
High Pass Filters
Each channel of the VTX is fitted with a switchable hi-pass
filter, which may be switched in as required to reject low-
frequency signals below 65 Hz. The filter has a slope of
18 dB/octave, to provide a high degree of low frequency
rejection.
The primary purpose of the filter is to avoid loudspeaker
transformer saturation when driving 100 V/70 V-line speaker
systems. (The VTX amplifiers’ outputs are designed to drive
low-impedances only, so an external transformer will be
necessary for amplifier channels to drive such systems. The
Cloud CXL-100T is suitable for use with the VTX4120;
transformers with higher ratings will be necessary for use
with the VTX4240 and VTX4400). Transformer saturation
creates unpleasant distortion and stresses the system, and
the high pass filter should always be switched in when
driving 100 V/70 V-line systems.
Use of the filter with low-impedance loudspeaker systems
is optional and at the discretion of the installer; switching
it in may help to enhance the clarity of speech, reduce
microphone handling noise and breath blasts.
Outputs
The VTX amplifiers’ speaker output connections are on
two adjacent 4-pin, 5 mm-pitch screw-terminal connectors
(mating connectors are supplied).
CH 1
CH 2
CH 1
CH 3
CH 4
-
+ -
+ -
+ -
+
Each channel’s output stage is designed to drive into an
impedance of not less than 4 ohms. Check the impedance of
the loudspeaker(s) in use and, taking into account any series
and/or parallel wiring, ensure that the total load on each
channel is not less than 4 ohms.
fig.6: Output Wiring
fig.5: RL-1 Wiring
1 2 3
REMOTE MUSIC
CONTROL
CONNECTOR
1 2 3
RL-1
USE TWO-CORE SCREENED CABLE