-7-
DC Trigger Connection
This connector provides the ability to trigger your amplifier on with an external DC voltage source
ranging from + 9 Vdc to +12 Vdc. With the main power switch in the off (down) position, the
amplifier can be turned on with voltage from any external DC source such as the +12 Vdc trigger
from the Parasound P/SP-1500 AV Processor/Preamplifier. Since it is optically coupled, the DC
trigger only requires 15 mA of current to activate the circuitry and turn on the amplifier.
AC Power Connections and AC Grounding
Before you connect the AC cord, make sure your amplifier's power switch is in the off position and
the external DC trigger is off. If possible, plug your amplifier directly to an AC wall outlet. Do not
connect the amplifier to the accessory AC outlet on your preamplifier or processor because the
amplifier's current draw exceeds the ratings of most preamplifier’s power switches and power cords.
If you use an external AC line conditioner or surge suppressor, make sure it can withstand the power
requirements of the amplifier listed in the specification section of this manual.
Operating the HCA-2205A
Refer to Figure #1
Power Switch
Manual Turn On
Press the upper side to turn the unit on manually; press the lower side to turn the unit off.
Automatic Turn On
When the power switch is in the off position, the power amplifier can be turned on with an external
DC voltage applied at the DC trigger connector on the rear panel. (see above)
Level Controls
Each channel has its own rear mounted "set and forget" input level control. Your amplifier will
sound best with these level controls set to maximum, where they are effectively out of the audio
signal path. However, if your preamplifier has very high gain, and its volume control cannot track
properly for left-right channel balance near its minimum position, it may be necessary to reduce the
input level control settings on the amplifier. When using the HCA-2205A in a THX installation, each
level control must be set at maximum to correspond to 0 dB THX reference level.
AC Line Indicator
The AC line indicator on the front panel of your amplifier lights to show you that AC is present at
the AC connector. This indicates that the AC cord is connected and that power is applied to the
amplifier.
Standby/Normal Indicators
When you first turn the amplifier on, the Standby indicator will light for about five seconds while the
internal circuits are stabilizing. After that, the Standby indicator turns off and the Normal indicator
lights to signal that the amplifier is operational.
