Adcom GFA-7300 - Manual (Page 12)

FRONT PANEL
NOTE! Product shown is the GFA-7400. The GFA-7300 is similar in appearance.
© On/Off Switch
The On/Off Switch controls power to the power transformer and circuits of the GFA-
7400/7300. Whenever the GFA-7400/7300 is energized the Power LED (O) will glow. To turn
the GFA-7400/7300 on, press the push-button. It will remain in the “engaged” position while the
unit is energized. To turn the GFA-7400/7300 off, press the push-button in and release and it will
move to the “disengaged” position.
o Power LED
This LED will glow whenever the On/Off Switch (O) is turned on and the GFA-7400/7300 is
energized. The Power LED indicates that there is AC voltage being fed to the amplifier, but it
does not signify that all the amplifier’s circuits are in operation. If, for example, one of the
Thermal Protection LED (©) glows, that amplifier channel will not produce sound even though the
Power LED may still glow. When the GFA-7400/7300 is turned off, the Power LED will take some
time to fade out completely. It may take up to 30 seconds to fully extinguish.
Additionally, the internal power transformer is provided with a thermostat which will interrupt
power into the transformer if its temperature exceeds 125°C. This high temperature will seldom, if
ever, be encountered unless the amplifier is subjected to abnormal conditions, such as operation
into loads of less than 3 ohms at very high listening levels, etc. If the AC Fuse (O) has not failed,
the Power LED is out, and the Thermal Protection LED (©) does not glow, this would indicate that
the thermostat within the transformer has opened.
Once the temperature within the transformer decreases to a normal level, the thermostat will
reset itself automatically and normal operation will resume. If you are to avoid tripping the
thermostat in the transformer continually, you must reduce the sound level demands, correct the
load impedance of the loudspeakers, or both.
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