Specifications

Operation l3
+.
Operation
IMPORTANT
All signal
source
equipment
should be
adequately
earthed. This
not only ensures
your
safety
but
eve-
rybody
else's
as well. Faults
can and
do occur
in
mains
connected
equipment where the
chassis
can
become'live"
if it is
not
properly
earthed.
ln these
instances
the fault
in a
"floating' (ungrounded)
piece
of
equipment
will look for
the shortest
path
to
ground
which could
possibly
be
your
amplifie/s input.
lf the
fault
cunent is
large enough
it will destroy the
input
to
your
amplifier
and look
for the next available
path,
which
may
be
you!
Before
making
any connections to
your
Piau/
Ptihzu
amplifi
er observe
the fol lowing:
1. Ensure
the mains voltage
supply matches
the
label
on the rear
panel
of
youramplifier
(+/-
1 0%).
2.
Ensure that the
power
switch is
OFF
(to
the
left -
0)
3.
Ensure
that
all system
grounds
(earth).
are
connectedfrom
a common
point.
Avoid
powering
equipment within a
system from multiple
power
sources
that may
be separated by largedistances.
4.
Check the continuity
of
all interconnecting
leads
to
your
amplifier,
ensure
that there are
no open
or
short circuited
conductors.
5.
Ensure that
the
power
handling of
your
load
(speakers)
can
adequately
cope
with
the
power
output
of
the
amplifier.
Before operat
ngyour Pfuf?r'hzuamplifi
er, ensure
that:
-
The attenuators
are
at the'OFF'
position
(fully
anticlockwise).
-
The
GROUND LIFT
Switch is not engaged
(should
be
in
the'ouf
position).
-
The BRIDGE
Switch
is
not engaged if
you
are
not
running
the amp in bridged
mode.
Powering
Up
t
REMEMBER
The
amplifier should
be the
last
piece
of equipment
thatyou
tum on
and thefirst
piece
of equipmentthat
you
tum
off.
We recommend
tuming
the
attenuators on
your
amplifier down
when
turning
the unit on.
When
you power
up
you
r
Pfu/Prltzu,your
ampl ifi er
goes
through an
establishment
period
before it will
accept signal. The lnrush
Cunent Supression
(lCS)
circuit
is
in
operation
for the first
0.5 seconds. This
l
imits the mains cunent to
prevent
"nuisance-tripping"
of circuit breakers.
During this
period
the THERMAUON
LED
willflash
red whilstthe
mains voltage
gradually
charges
up the
power
supply. You will then hear
a
relay
"clicK,
indicating
mains
is now
directly applied to
the
amplifi
er
and
the THERMAUON LED willbe
green.
While
the ICS circuit operates there is
also a 30dB
mute
on
the
signal
input.
Aftertwo
seconds
this
mute
will release,
allowing any applied
signal to
pass
unattenuated.
When switching the
amplifier off, wait
a
couple
of
seconds
before switching the
unit on again.
This
allows
the ICS circuit to reset.
Level Matching
The normal operating
position
for
the attenuator
is
the
"0
dB"
position
(fully
cloclwise,
no attenuation).
ln
this
position
the
amplifier operates
at
full
gain.
Turning the attenuator
back
(anticlockwise)
reduces
the input
sensitivity by the amount
marked on
the
attenuator
scale
(dial).
NOTE:
lf full
power
output is required
you
should operate
your
amplifier with the front
panel
attenuator
above
the -15d8
position,
othenrise
clipping of the input
circuitry
and
its resultant
distortion will
occur before
full output
power
is achieved.
Sensitivity
Youramplifier is a lineardeviceoperatingwith
afixed
input
to output voltage
gain
(less
attenuation). The
maximum
output
voltage
sldng is determined
by the
applied mains voltage, load,
load
type and
the
duty
cycle of the applied signal.
The voltage
gain
factor of
your
amplifier is:
37
(31.5
dB)
for
a PA800
45
(33.0
dB) for a PA1200
Th e i n
put
sensiti vity
f o
r
y
our Pr4am/?4tzu amp
I ifi er
when
the attenuator is at the "O'
dB attenuation
position
(fully
clockwise) is
nominally:
+4.0d8
(1
.23 volts in) for rated
power
into a 8 ohm
load.
+3.0d8
(1
. 10 volts in)
for rated
power
into a 4 ohm
load.
Asbalian
Monitor,
/tu