Nexo NXAMP - Manuel (Page 9)

ENGLISH
PAGE
9
SETTING-UP ADVICE
DATE: 03/12/2004
Recommendations for wiring the sense lines
The impedance of the sense inputs of the TDcontroller are high, so currents are low and therefore light
duty cable can be used. If the TDcontroller is housed in the amplifier racks an unshielded cable may be
used.
If the TDcontroller is located remotely - at the mixing position - a shielded cable is recommended, without
using the shield as a conductor. The cable must be well protected from public access, as it carries
potentially dangerous amplifier voltage.
When one of the channels is not being used and the corresponding sense line is disconnected, cross talk
onto the inactive sense line may in some cases produce signals capable of causing the inadvertent
illumination of the Sense LED on that channel; although this has no effect on the internal operation of the
TDcontroller, it can be cured by short-circuiting the terminals of the inactive sense line.
Recommendations for wiring the audio outputs
The output stages can drive several amplifiers in parallel; however it is not advisable to work with loads of
less than 1kOhm(and strictly forbidden to drive less than 600Ohms
). It is best to check the impedance
characteristics of the amplifier inputs - supplied by the manufacturer - to check how many amplifier
channels can be paralleled. Where precise information is not available (and taking 10kOhm as the
minimum value possible), ten channels in parallel per output is a sensible maximum.
Electromagnetic environments
The emission (this word describes all types of electromagnetic noise radiated by the equipment)
requirements which have been applied to Nexo’s TDcontrollers are the stringent requirements of the
”Commercial and light industrial environment” of the product family EMC standard for emission.
The immunity (this word describes the ability to cope with electromagnetic disturbance generated by
other items and natural phenomena) requirements that we have considered exceed those applicable to
the ”Commercial and light industrial environment” of the product family EMC standard for immunity. In
order to provide a further safety margin, we recommend that you do not operate the TDcontrollers in the
presence of electromagnetic interference exceeding half of the limits found in this standard.
Low Z
1 2 3
Low Z
1 2 3
TDcontroller
Amplifier Mixing Desk
1 2 3 1 2 3
+ -
+ -
+ -
+ -
Low Z
L
o
w Z
PE PE
PE
Safety
Ground
SHIELD SHIELD
IN OUT
These two EMC standards are those applicable to pro-audio equipment for the implementation of the
”EMC directive”.
Analogue signal cables
Analogue signals should be connected to the input
and output ports of the TDcontroller via shielded
twisted pair or starquad cable fitted with XLR
connectors on the TDcontroller side. We
recommend the use of low transfer impedance
cables with a braided shield and a transfer
impedance below 10 mΩ/m. For the sense inputs,
the noise requirements are not as stringent, and
any kind of twisted pair cable will be adequate.
The TDcontroller is intended to be used with
USER MANUAL LOAD2_22