Adcom GFA7807 ユーザーズマニュアル
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DESCRIPTION OF UNIT: REAR PANEL
(1) Inputs
The GFA-7805 and GFA 7807 have both balanced and unbal-
anced inputs for each channel. The unbalanced connection
is made via the gold plated RCA jack and the balanced con-
nection is made via the XLR input connection. Each channel
also has a switch which selects the type of input for each
channel. Make sure the switch is in the appropriate posi-
tion for the type of connection you have choosen. For best
performance, always use high quality interconnects. Your
ADCOM dealer can help select the best cable for your needs.
anced inputs for each channel. The unbalanced connection
is made via the gold plated RCA jack and the balanced con-
nection is made via the XLR input connection. Each channel
also has a switch which selects the type of input for each
channel. Make sure the switch is in the appropriate posi-
tion for the type of connection you have choosen. For best
performance, always use high quality interconnects. Your
ADCOM dealer can help select the best cable for your needs.
(2) Outputs
The GFA-7805’s and GFA-7807’s connections to the
loudspeakers are made through high-grade, 5-way,
gold-plated binding post terminals. There are two
terminals for each speaker, which are colored RED for the
positive (+) output and BLACK for the negative (-) output.
loudspeakers are made through high-grade, 5-way,
gold-plated binding post terminals. There are two
terminals for each speaker, which are colored RED for the
positive (+) output and BLACK for the negative (-) output.
The binding posts will accept a variety of connector types.
The most secure and prevalent of these is the “U”-type
spade connectors (at least 0.25’’ wide and maximum width
of 0.57”). The terminal will also accept bare wire (up to
AWG1O) and “banana” type plugs (single or dual).
The most secure and prevalent of these is the “U”-type
spade connectors (at least 0.25’’ wide and maximum width
of 0.57”). The terminal will also accept bare wire (up to
AWG1O) and “banana” type plugs (single or dual).
(3) I2V DC Trigger
The GFA-7805 and GFA-7807 are very high power amplifiers
and as such must be directly connected to the wall outlet
or an appropriate surge protector or AC line conditioner.
It must never be connected to the ‘switched’ outlets on
the rear panel of a pre-amplifier. Usually this would mean
that when you turn on/off your pre-amplifier you would
have to turn on/off your power amplifier separately. We
have, however, provided the ability to control the OFF/ON
function of the GFA-7805/7807 by a l2V DC output jack
on the rear of certain ADCOM pre-amplifiers. When using
this feature the front panel Power Switch must be left in
the in “on” position. To connect the preamplifier 12V DC
output jack to the amplifier 12V DC jack, you will need a
monaural mini phone plug to monaural mini phone plug
cable. Contact your dealer for information on using this
feature with ADCOM and other brand pre-amplifiers.
and as such must be directly connected to the wall outlet
or an appropriate surge protector or AC line conditioner.
It must never be connected to the ‘switched’ outlets on
the rear panel of a pre-amplifier. Usually this would mean
that when you turn on/off your pre-amplifier you would
have to turn on/off your power amplifier separately. We
have, however, provided the ability to control the OFF/ON
function of the GFA-7805/7807 by a l2V DC output jack
on the rear of certain ADCOM pre-amplifiers. When using
this feature the front panel Power Switch must be left in
the in “on” position. To connect the preamplifier 12V DC
output jack to the amplifier 12V DC jack, you will need a
monaural mini phone plug to monaural mini phone plug
cable. Contact your dealer for information on using this
feature with ADCOM and other brand pre-amplifiers.
(4) AC Fuse
The AC Fuse protects the electronic circuits of the GFA-
7805/7807. This fuse, normally, will fail only if there
7805/7807. This fuse, normally, will fail only if there
is an overload within the GFA-7805/7807. If your fuse
fails please contact your dealer or ADCOM directly for a
replacement or servicing.
fails please contact your dealer or ADCOM directly for a
replacement or servicing.
(5) AC Power Cord
The AC cord provides power to operate all the GFA-
7805/7807’s circuits. Its plug can be connected to a
standard wall outlet provided the outlet supplies a voltage
compatible with the power requirements printed on the
rear panel of the GFA-7805/7807.
7805/7807’s circuits. Its plug can be connected to a
standard wall outlet provided the outlet supplies a voltage
compatible with the power requirements printed on the
rear panel of the GFA-7805/7807.
DESCRIPTION OF UNIT
: FRONT PANEL
(6) On/Off Switch
The On/Off Switch controls power to the power
transformer and circuits of the GFA-7805/7807. Whenever
the GFA-7805/7807 is energized the Power LED (7)
will glow. To turn the GFA-7805/7807 on, press the
push-button. It will remain in the “engaged” position while
the unit is energized. To turn the GFA-7805/7807 off, press
the push-button in and release and it will move to the
“disengaged” position.
transformer and circuits of the GFA-7805/7807. Whenever
the GFA-7805/7807 is energized the Power LED (7)
will glow. To turn the GFA-7805/7807 on, press the
push-button. It will remain in the “engaged” position while
the unit is energized. To turn the GFA-7805/7807 off, press
the push-button in and release and it will move to the
“disengaged” position.
(7) Power LED
This LED will glow whenever the On/Off Switch (6) is
turned on and the GFA-7805/7807 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 LEDs (9) glows, that amplifier channel
will not produce sound even though the Power LED may
still glow. When the GFA-7805/7807 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 (4) has not failed, the
Power LED is out, and the Thermal Protection LED (9) 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
turned on and the GFA-7805/7807 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 LEDs (9) glows, that amplifier channel
will not produce sound even though the Power LED may
still glow. When the GFA-7805/7807 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 (4) has not failed, the
Power LED is out, and the Thermal Protection LED (9) 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