Fig. 6 SIA2-100 front panel and connection sockets
2.3: Outputs
The SIA2-100 rear panel, as illustrated in Fig. 7 carries the
power amplifier outputs for connection to loudspeakers and also
a preamp stereo line level output for connection to additional
ancillary equipment e.g. power amp or a separate zone
in the home. The headphone output, via a 6.35mm/0.25” jack,
is front panel-mounted and is illustrated in Fig. 6.
Connections to loudspeakers are made via the two pairs of
proprietary ATC loudspeaker terminals.The positive terminal is
marked with a red trim and the negative terminal is marked with
a black trim.The left and right channels are clearly marked and
correspond to the left and right inputs.The loudspeaker cable
used for connection between the amplifier outputs and the loud-
speakers will usually have some identification of the positive
conductor; a red mark, but sometimes a moulded stripe on the
insulation. Care must be taken that both the left and right
loudspeakers are connected with correct polarity. If the pair of
loudspeakers are connected out of phase, the result will be a
serious lack of low frequency output and a very wide stereo
image with no defined phantom centre.
2.4: Operation
Once connected to the mains power and powered up using the
rear panel mains switch, the SIA2-100 will assume the input
selected when the unit was last turned off. Alternative inputs
may be selected by pressing the Input push button on the front
panel.The Input selected will be shown on the display.
Pressing the Standby button on the front panel will place the
unit into standby; the standby indicator will glow red. Pressing
the standby button again will take the unit out of standby.
The indicator will extinguish.
Output level is controlled by the rotary volume control on the
front panel, the position of which is indicated by the black
pointer. Clockwise rotation will increase the output level. It is
good practice to lower the volume setting before switching on
the unit or any associated equipment, or while changing the
input selection or changing connections from/to the out/inputs.
All the above commands are duplicated on the remote control.
A headphone output is provided via a front panel-mounted
6.35mm/0.25" jack socket and will drive a very wide range of
popular headphones.When headphones are connected, the signal
to the power amplifier and preamplifier output will be muted.
The stereo line level output on the rear panel can be used to
drive an additional power amplifier or zone.
Excessively high operating temperatures are potentially very
damaging.The SIA2-100 contains circuitry to monitor the heat-
sink temperature.The red standby LED will flash to warn the
user that the heatsink temperature is rising. Action should be
taken to reduce the power output level, or ensure that the
ambient temperature around the SIA2-100 is not too high,
e.g. by placement too near a radiator etc. If remedial action is
not taken and the temperature continues to rise, the SIA2-100
will shut down, indicated by the standby LED glowing solid red.
It then becomes necessary to turn the unit off at the mains
switch and allow the SIA2-100 to cool down.The unit will
not power up again until the temperature of the heatsink is at
an acceptable level.
