Adcom GFA-7400 Service Manual

4
POWER SUPPLY PCB
SCHEMATIC ADCOM PART NUMBER DESCRIPTION
LOCATION
C01 12005010 CAPACITOR ELEC 1000uF 25V
C18 12001510 SPARK KILLER
C02 12005120 CAPACITOR ELEC 220uF 16V
D1-D6 16004004 DIODE 1N4004
F1 19001200 MAIN FUSE 12A
F2 19000100 STANDBY FUSE 1A
K1 28007400 TURN-ON RELAY
LED1 16001245 POWER LED LTL1204 (RED)
Q1 33001300 TRANSISTOR MPSA13
R1 27003110 RESISTOR 1K 1W
R2 27004270 RESISTOR 3.32K
R3 27004200 RESISTOR 10K
R4 27004270 RESISTOR 3.32K
T1 24007402 STANDBY TRANSFORMER
TH1 31005800 THERMISTOR CL100
U2 21007812 REGULATOR IC 7812
37007400 POWER SWITCH
OTHERS
SCHEMATIC ADCOM PART NUMBER DESCRIPTION
LOCATION
T2 24007401 MAIN TRANSFORMER
13005805 FOOT
13007401 FRONT PANEL
13007402 HEATSINK
11001155 POWER BUTTON
11001165 POWER BUTTON FRAME
13007400 TOP COVER

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)