LOUDSPEAKER CONNECTIONS
The loudspeakers should be connected using a suitable pair of cables designed specifically
for audio use. The higher the quality the better your system will sound. Screw terminals
allow for either bare wire or spade lug connectors to be passed through the hole or around
the bush. Tighten the terminal fully after fitting the speaker wire.
It is
very important
to connect the loudspeakers to the loudspeaker terminals in the correct
phase. Cables are normally polarised with a line or a raised bump on the positive side. If
one channel is not connected in the same fashion as the other, a severe loss of bass per-
formance and a spreading of the stereo image will result.
It is not recommended to use more than two pairs of 8
Ω
speakers running from the amplifier
at one time. However, bi-wiring of one pair of speakers, using the four sockets, can
improve the sound of your system. Please consult your dealer for advice if you are unsure.
BRIDGED MONO
If the amplifier is to be used in a Bridged Mono (balanced) configuration, a P43 pre-amplifier
fitted with a bridging driver board and a further A43 amplifier will be required. Each amplifier
should be wired to drive one loudspeaker only (left or right). The major difference in the
wiring of a balanced system is that the loudspeakers are not connected to ground. The
loudspeaker wires should be connected between the live connections of the left and right
outputs on the rear of the amplifier. Phasing of the leads is still important and therefore if
the positive (marked) wire is connected to the right connector on one channel (Right) it
should be wired the same connector on the other channel.
Bi-Wiring is still possible, but it is not advisable to connect more than one 8
Ω
speaker to a
Bridged (balanced) A43 at a time as it will overheat and could possibly damage the amplifi-
er. Do not connect the negative loudspeaker wire to any ground connector or the bridging
mode will be defeated.
N.B. It is very important not to short the loudspeaker cables together when the other
ends are still connected to the amplifier otherwise permanent damage can result. If it
is necessary to move or change the location of your loudspeakers, make sure that
you switch off the amplifier from the mains first.
INPUT CONNECTION
The input sensitivity of the Power amplifier is 530mV's. Connection is made via the two
RCA Phono (Cinch) type sockets on the rear panel marked - INPUT, which are wired in un-
balanced mode and marked left and right.
If a Bridged Mono application is required, it is necessary to use both left and right inputs as
a form of balanced mono input, carrying the positive and negative halves of the signal. For
further details read specific instructions accompanying the plug-in bridging board for the
P43 Pre-amplifier.
OPERATING THE A43
Make sure that the unit is on a suitable table or Hi-Fi equipment cabinet. It is important to
allow adequate ventilation to the heatsink, in the centre of the unit. Avoid obstruction of the
ventilation slots on the top cover. It may be necessary to place the power amplifier on the
top of other equipment to allow for this. To switch-on the unit press the button marked
POWER on the right hand side of the front panel. To protect the loudspeakers connected to
the amplifier from dangerous DC voltages, an internal 10 Amp relay switches off the outputs
on switch-on and in the case of a failure etc.
When the amplifier is switched on there will be a delay of about 3 seconds, but turn-off
should be instantaneous. To indicate the status of the amplifier, the colour POWER LED
indicator will be yellow on initial switch-on. When the amplifier reaches operating condition,
at which time the relay will drop in, the LED will change to green. If a fault condition occurs
the relay will switch both speaker outputs off and the POWER indicator will turn to red.
Return the amplifier to the supplying dealer if the fault code (red) is visible.
Your A43 amplifier is designed to give you years of reliable use. However, it is necessary to
take care of your possession, so never overheat it, connect more than the appropriate num-
ber of speakers or short out the speaker connections. If an adjustment is needed, it is
always advisable to return it to the supplying dealer for his expert help. If you are unfortu-
nate enough to need service work to be carried out on your amplifier, it should be returned
to your dealer or the manufacturer in the original packing material if possible.
Rear view of A43
Rear view of P43
L
R
Signal
Input
L
R
Speakers
Output
Ground
Mains Inlet
1
2
3
L
R
A43
Rear
Panel
Signal
Input
L
R
Loudpeakers
Ground
Mains
R
L
A43
Rear
Panel
Signal
Input
L
R
Loudpeakers
Ground
R
L
1
2
3
P43
Rear
Panel
L
R
A43
Rear
Panel
Signal
Input
L
R
Loudpeakers
Ground
R
L
A43 Right
A43 Left
Pre-amp
+ -
+ -
+
-
+
-
