rcf UP 4061 Manual De Uso Y De Instalación página 12

17) "BALANCED IN" input
Used for connecting the device that supplies the
audio signal to be ampli ed (preampli er, mixer,
another power ampli er, etc.). This socket can be
used in alternative to the UNBALANCED IN, or
both inputs can be used with the "priority"
function, which gives BALANCED IN priority over
UNBALANCED IN(see "PRIORITY terminal"). The
input can accept balanced signals at 0 dB.
18) "STAND-BY" terminal
In order to use this terminal, the "stand-by" mode
must be activated by the RCF S.p.A. SERVICE
CENTRE. This function makes it
possible to switch on the power ampli er by
remote control. When the unit is switched on
using the POWER switch (ref. 4 - Fig. 1), it
automatically goes into stand-by mode, and
operation is blocked; to control ampli cation and
signal transmission, the terminals STAND-BY and
GND (ref. 19) must be short circuited together,
e.g. using an electrical contact.
19) "GND" terminal
Earth terminal for the STAND-BY input.
20) "OVERL." terminal
When the overload protection circuit is tripped
and the power ampli er stops working, the
OVERLOAD light on the front panel comes on, and
a voltage of 18 Vdc (max. 300 mA) is made
available on the OVERL. output which can be used
for driving a LED or an auxiliary relay.
21) "GND" terminal
Earth terminal for the OVERL. output.
22) AC protection fuse
The fuse that protects the alternating current
power supply circuits of the power ampli er can
be accessed by removing the fuse holder. In the
event of a blown fuse or a change in the supply
voltage, the fuse must only be replaced by an
RCF S.p.A. SERVICE CENTRE.
23) Power cable socket
For connecting the power cable supplied with the
power ampli er.
24) Supply voltage selector
Used for selecting the supply voltage for the
power ampli er between 115 Vac and 230 Vac.
The selection must only be made by an
RCF S.p.A. SERVICE CENTRE.
25) H.P. switch
When this switch is lowered, a high-pass lter is
activated which attenuates all frequencies lower
than 300 Hz. This lter can be useful for
improving voice intelligibility in spaces that are
particularly subject to reverberation. Using the
H.P. and L.P. lters together makes it possible to
correctly drive horn speakers which have a
limited frequency response and can thus be
damaged when driven with excessively high or
low frequencies.
26) L.P. switch
When this switch is lowered, a low-pass lter is
activated which attenuates all frequencies higher
than 7 kHz. This lter can be useful for
eliminating acoustic feedback from speakers to
microphones.
27) "UNBALANCED IN" input
This coaxial RCA socket is used for connection
with the device that supplies the unbalanced
audio signal to be ampli ed (preampli er, mixer,
another power ampli er, etc.). This socket can be
used in alternative to the BALANCED IN, or both
inputs can be used with the "priority" function,
which gives BALANCED IN priority over
UNBALANCED IN(see "PRIORITY terminal"). Using
the SENSITIVITY switch, the sensitivity level of the
input can be selected between -20 dB and 0 dB.
28) "PARALLEL OUT" output
This coaxial RCA output is connected in parallel
with input (27), and can be used for sending the
audio input signal to another power ampli er, a
supplementary ampli er, etc..
29) "SENSITIVITY" switch
This switch is used for selecting the sensitivity of
the UNBALANCED INbetween the values of 0 dB
and -20 dB; the latter value makes it possible to
connect equipment that has a particularly low
output level (e.g. 80 mV).
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