Adcom GFA-7705 User Manual

WARNING
THERE ARE NO USER-SERVICEABLE PARTS OR FUSES INSIDE THE GFA-7705/07. In the event that the
amplifier’s rear-panel circuit breaker fails to reset (opens again when power applied to unit and unit
turned on) you must refer the amplifier to ADCOM Factory Service or ADCOM Authorized Service Center.
Do not open the amplifier nor remove the topcover-Hazardous and Potentially Lethal Voltage Present
and Warranty may be voided.
12VDC Triggering (3a)
ADCOM has provided the installer the ability to control the OFF/ON function of the GFA-7705/07 by a
12Volt DC output jack on the rear of certain pre-amplifiers and tuner pre-amplifiers. When using this
feature the front panel Power Switch must be left in the in “on” position. To connect, you will need a
monaural mini phone plug to monaural mini phone plug cable of appropriate length (not included) to
reach from the rear panel of the amplifier to the rear panel of the pre-amplifier. Contact your dealer
for information on using this feature with ADCOM and other brand pre-amplifiers. Although 12VDC is
optimal, the circuit will operate from approx. 5 to 30VDC. Center conductor (tip) is positive (+).
AC Circuit Breaker (3b)
The 15-Amp AC Breaker protects the electronic circuits of the GFA-7705/07. Normally, this breaker will
open only if there is an overload or a component failure within the GFA-7705/07.
If the Power LED (7) does not glow, it may be an indication that the AC Breaker has blown. If you are
using the 12VDC Triggering feature (above) it may be possible that there is no trigger voltage present or
a problem exists with that connection.
To determine if the problem is caused by a malfunction in the 12VDC system, remove the small plug
inserted into the 12VDC Triggering jack. Press the front panel power switch to turn off the amp, and
immediately re press the power switch. If the problem is caused by the 12VDC triggering circuit the
amp will turn on and the LED will glow.
DO NOT attempt repair of the 12VDC system. If you are not sure, or the amplifier displays other
symptoms, please consult the RESOLVING PROBLEMS section on page 13.
AC Power Cord (4)
The AC cord provides power to operate all the GFA-7705/07’s circuits. The GFA-7705/07 is a very high
power amplifier and as such must be directly connected to the wall outlet or an appropriate (non-
current limiting) surge protector or AC line conditioner of 20-Amp service capability.
NOTE: As previously described on Page 4, the attached plug is a 20-Amp fitting which, in order for the
amplifier to deliver its rated power output, should not be defeated in order to accomodate standard
15-amp household wall outlets.
Please consult with your dealer and/or licensed electrician for conversion of a 15 amp outlet and panel
circuit to a 20 amp circuit.
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Adcom GFA-7705 Specifications

Power

power rating into 8 ohms	200 Watts continuous average power per channel
power rating into 4 ohms	300 Watts continuous average power per channel
power consumption idle 7 channel	120W

Audio Performance

frequency response at 1 watt into 8 ohms	+0, -0.22dB
power bandwidth	3 Hz to 130kHz
dynamic headroom into 4 ohms	1.90 dB

Electrical Specifications

input sensitivity for 1 watt output	0.1 volts
input sensitivity for 200 watts output	1.40 volts
damping factor (20Hz to 20kHz)	800

Dimensions and Weight

chassis dimensions	8.5” (216mm) x 17” (432mm) x 17.5” (444.5mm)
maximum dimensions	9 3/8” (238mm) x 17” (432mm) x 18.5” (470mm)
unit weight GFA-7707	35.5 kg