Adcom GFA-7400 User Manual

FRONT PANEL
NOTE! Product shown is the GFA-7400. The GFA-7300 is similar in appearance.
0 On/Off Switch
74nn^n? n S5 S WitC ^ 0r ll r0lS power to the Power transformer and circuits of the GFA-
the rFA° 74 n n / 7 ^nn Ver ^ GFA ' 7400/7300 is energized the Power LED (©) will glow. To turn
the GFA - 74 ° 0 / 7300 on, press the push-button. It will remain in the “engaged” position while the
move T ° tU H - the GFA " 7 400/7300 off - P re s s the push-button in and release and it will
move to the disengaged position.
0 Power LED
This LED will glow whenever the On/Off Switch (®) is turned on and the GFA-7400/7300 is
TntTnnt * ft m(i ^ es that there is AC volta 9 e 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 (©) has not failed
I! “£> is ° U t ’ a n ? th © 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.
12

Adcom GFA-7400 Specifications

Power

continuous power per channel into 8 ohms	100 watts
continuous power per channel into 4 ohms	150 watts
power consumption quiescent	96 VA
maximum power consumption	1440 VA
power consumption at 100 watts into 8 ohms	1165 VA
power supply voltage	115 VAC - 50/60 Hz

Distortion

IM distortion SMPTE at 8 ohms	≤ 0.075%
IM distortion SMPTE at 4 ohms	≤ 0.075%
IM distortion CCIF at 8 ohms	≤ 0.025%
IM distortion CCIF at 4 ohms	≤ 0.025%
THD + noise at 100 watts into 8 ohms at 20Hz	0.0012%
THD + noise at 100 watts into 8 ohms at 1kHz	0.0012%
THD + noise at 100 watts into 8 ohms at 10kHz	0.02%
THD + noise at 100 watts into 8 ohms at 20kHz	0.025%
THD + noise at 150 watts into 4 ohms at 20Hz	0.025%
THD + noise at 150 watts into 4 ohms at 1kHz	0.025%
THD + noise at 150 watts into 4 ohms at 10kHz	0.035%
THD + noise at 150 watts into 4 ohms at 20kHz	0.045%

Performance

frequency response at 1 watt into 8 ohms	+0, -0.25 dB
power bandwidth	1.5 Hz to 65 kHz
dynamic headroom into 4 ohms	2.5 dB
signal to noise ratio	≥ 110 dB
gain	29 dB
input sensitivity for 1 watt	0.1 volts
input sensitivity for 100 watts	1.0 volts
input impedance	50 kΩ
damping factor	≥ 400
rise time	4.5 µS

Weight and Dimensions

chassis dimensions	5” (127mm) x 17” (432mm) x 14” (355.6mm)
maximum dimensions	5 3/4” (146mm) x 17” (432mm) x 15” (381mm)
weight	42 lb. (19.1 kg)
packed weight	48 lb. (22.8 kg)