Fuses and Mains
Mains Voltage selection, safety fuses and Earth-Lift configuration are located under the safety cover on
the front panel.
The mains power cable can be located on the front or on the back of the PS10Amp. No other control or
connection exists on the back of the amplifier. At installation nothing else is required than sufficient air flow
path on the back of the PS10Amp.
Stand alone Amplifiers
Recommended Power
NEXO recommends high power amplifiers in all cases, budget constraints being the only reason to select
lower power amplifiers. If a problem occurs on an installation without protection, the use of a lower power
amplifier generating half their rated output power (-3dB) will not prevent possible damage. This is due to
the fact that the RMS power handling of the weakest component in the system is always 6 to 10 dB lower
than the amps' rating
Current Rating
It is very important that the selected amplifier behaves correctly under low load conditions. A speaker
system is reactive by nature, on transient signals like music it will require much higher instantaneous
current than its nominal impedance would indicate (four to ten times more). Amplifiers are usually
specified by their continuous RMS power into resistive loads (which is irrelevant); the only useful
information in that regard is the specification into a 2 ohms load. It is possible to make an amplifier
listening test by loading the amplifier with twice the number of cabinets considered for the application (2
speakers per channel instead of one, 4 instead of 2…) and modulating at high level (onset of clipping). If
the signal does not noticeably deteriorate the amplifier is well adapted (overheating after approximately ten
minutes is normal but thermal protection must not operate too quickly after starting this test).
Gain
It is very important to know the voltage gain of all amplifiers present in your set-up. This will ensure the
correct alignment of your system and may be obligatory (for reliability) in cases where only one
TDcontroller drives several amps. The tolerance should be about ±0,5 dB. In practice this can be difficult
to achieve:
• Some amplifier brands have an identical input sensitivity for models of different power ratings (this means
DIFFERENT VOLTAGE GAIN for each model). This problematic practice, inherited from non-professional
applications, is easily detected when the manufacturer specifies the same input sensitivity for all its range
(like 775mV/0dBm or 1.55V/+6dBm). This translates into very high gain values on higher power models.
• Other brands do offer constant gain, but often only within a given product range (like higher gain on all
semi-professional amps).
• Even if a manufacturer is aware of this problem and applies the constant gain rule to all its models, the
value chosen is not necessarily the same as other manufacturers.
• Some manufacturers deliver products where manufacturing tolerance on the same model is ±1dB or
more. Worse, the manufacturer might agree to modify this gain at the customer’s request without clear
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