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Ventilation Requirements
To insure safe and reliable operation, it is very important that the amplifier has plenty of ventilation to
prevent overheating and automatic shut down from its thermal protection circuitry. Please observe the
following ventilation guidelines when installing your amplifier in a cabinet or other enclosed area:
1) If you are not using a fan, allow at least six inches on each side and above the amplifier, and do
not close off the front with a cabinet door or panel.
2) If you are enclosing the amplifier within an equipment cabinet, use a fan to draw in cool air and
exhaust warm air. Two vent holes are required: one for intake and one for exhaust.
3) Do not place the amplifier on carpeting that will obstruct the air flow into the bottom of the
amplifier chassis and heatsinks.
4) Avoid stacking components. If you do stack components, you must use a fan to circulate the
warm air that will quickly become trapped between them when they are powered on.
Making Connections to the HCA-3500
Refer to Figure #1
Leave the AC cords disconnected before making any signal or speaker connections. When making
connections to the amplifier, make sure there is no strain or tension on the input leads, speaker wires, or
AC cord that could cause them to pull loose.
RCA Jack Input Connections
You can connect the output of your preamplifier or processor to the RCA input jacks in a variety of ways:
Normal Unbalanced Non-Inverting Input
Connect the unbalanced outputs of your preamplifier to the left and right positive (+) inputs only. With
this connection, the HCA-3500's output is non-inverted; a positive signal at the input results in a positive
signal at the output.
Unbalanced Inverting Input
Connect the unbalanced output of your preamplifier to the to the left and right negative (—) inputs only.
With this connection, the HCA-3500's output is inverted; a positive signal at the input results in a negative
signal at the output.
Balanced RCA Inputs
Connect the left and right positive (+) output of your preamplifier to the left and right positive (+) inputs
of the HCA-3500 and connect the left and right negative (—) output of your preamplifier to the left and
right negative (—) inputs of the HCA-3500. These balanced connections provide an alternative to using
an XLR connector if your preamplifier is equipped with (+) and (—) RCA output connectors.
XLR Input Connections
If your preamplifier is equipped with balanced XLR output connectors, you can use these connections
as an alternative to the RCA jacks. The industry standard pin assignment for the
HCA-3500's XLR input connector is Pin 1: Ground, Pin 2: Positive (+), and Pin 3: Negative
(—)
.
