Bose® equalisation modules (optional), Installation, General notes – Cloud Electronics CXV-225 User Manual
Page 11: Emc considerations earthing

CXV-225 & CXV-425 User Manual v1.0
11
BOSE® Equalisation Modules (Optional)
The CXV-225 and CXV-425 are compatible with Bose®
Series II loudspeakers; a single-channel Bose® equalisation
module may be fitted to as many channels as necessary.
Equalisation modules for the following Bose® models are
available:
Panaray® MA12
•
Panaray® 402-II, 502B and 502BEX
•
Panaray® LT Series: Models 3302, 4402, 9402 and 9702
•
Freespace® DS 16 range
•
Freespace® Model 16
•
Freespace® Model 32 range
•
Other modules are available; please enquire.
Installation
With the power turned off and the mains cable
•
removed, remove the top panel.
Refer to the pcb layout diagrams on
•
page 13. The
modules plug into the white 12-pin connectors on the
PCB. Note the header connectors on the PCB have two
notches on one side only; these engage with lugs on
the equalisation module’s mating connector to ensure
correct orientation.
After fitting equalisation modules to any channel(s),
•
the corresponding module bypass jumper(s) must be
removed in order for the module to function. Refer to
the pcb layout diagrams for jumper locations.
Replace the top cover with the original screws after
•
fitting
General Notes
EMC Considerations
CXV Series amplifiers fully conform to the relevant
electromagnetic compatibility (EMC) standards and are
technically well behaved. You should experience no problems
interfacing units to other items of equipment and under
normal circumstances, no special precautions need to
be taken. If the unit is to be used in close proximity to
potential sources of HF disturbance such as high power
communication transmitters, radar stations and the like, it is
suggested that input signal leads be kept as short as possible.
Always use balanced interconnections wherever possible.
Earthing
When several mains powered units are connected together
via their signal cables, there is a risk of one or more earth
loops which may cause an audible hum on the system even
with the gain controls set to minimum.
The 0 V rail of a CXV Series amplifier is directly coupled to
the chassis ground. No interconnection problems should be
encountered, but if there is any hum or other extraneous
noise when source equipment is connected, the situation can
generally be remedied by observing the following guidelines:
Always connect sources using balanced connections
•
wherever possible, with the cable screen only connected
at the receiving end (amplifier input).
Use audio isolating transformers (readily available from
•
trade suppliers) at the inputs if necessary. These will
ensure that the amplifier is electrically isolated from the
source equipment.
The signal source units should be located as close as
•
possible to the amplifiers and the metal housing of
the various units should not be electrically connected
together through the equipment rack. If this is a
problem, rack isolating kits are available from specialist
hardware suppliers. If the problem persists, try to
connect all interconnected units, including power
amplifiers, to a common power source to ensure a
common ground is provided.