Adcom GFA-5300 Service Manual

5
a GFA-5300 VOLTAGE CONVERSION
Certain versions of the GFA-5300 are cabable of operating at multiple voltages.The conversion
described below is for multivoltage versions of the GFA-5300. Multivoltage versions of the GFA-5300
have removable power cords.
Converting from 115VAC to 230VAC
1) With the Unit unplugged, remove the top cover of the GFA-5300.
2) Locate the Power and Standby PCBs at the front of the unit (pictured below).
3) Remove jumpers J201, J202, J204 and J205.
4) Add jumpers J203 and J206.
5) Replace the rear panel 6A main fuse with a 3A fuse.
6) Add sticker to back of unit indicating new operating voltage and fuse rating.
7) Replace top cover and test on 230VAC source.
Converting from 230VAC to 115VAC
1) With the unit unplugged, remove the top cover of the GFA-5300.
2) Locate the Power and Standby PCBs at the front of the unit (pictured below).
3) Remove jumpers J203 and J206.
4) Add jumpers J201, J202, J204 and J205.
5) Replace the rear panel 3A main fuse with a 6A fuse.
6) Add sticker to back of unit indicating new operating voltage and fuse rating.
7) Replace top cover and test on 115VAC source.
Figure 1 - GFA-5300 Power and Standby PCBs showing J201 - J206
J202
J203
J201
J206
J205
J204

Adcom GFA-5300 Specifications

Power

power rating into 8 ohms	80 watts continuous average power per channel
power rating into 4 ohms	125 watts continuous average power per channel
power consumption - quiescent	100 VA
power consumption - maximum	720 VA
power consumption - 80 watts into 8 ohms	510 VA
power consumption - 125 watts into 4 ohms	720 VA
power supply voltage	115 VAC - 50/60 Hz

Distortion and Noise

IM distortion SMPTE 8 ohms	≤ 0.07%
IM distortion SMPTE 4 ohms	≤ 0.07%
IM distortion CCIF 8 ohms	≤ 0.035%
IM distortion CCIF 4 ohms	≤ 0.035%
THD + Noise at 80 watts into 8 ohms 20Hz	0.018%
THD + Noise at 80 watts into 8 ohms 1kHz	0.02%
THD + Noise at 80 watts into 8 ohms 10kHz	0.07%
THD + Noise at 80 watts into 8 ohms 20kHz	0.14%
THD + Noise at 125 watts into 4 ohms 20Hz	0.018%
THD + Noise at 125 watts into 4 ohms 1kHz	0.02%
THD + Noise at 125 watts into 4 ohms 10kHz	0.08%
THD + Noise at 125 watts into 4 ohms 20kHz	0.165%
signal to noise ratio (A weighted)	≥ 100 dB

Frequency and Gain

frequency response	+0, -0.25 dB from 10Hz to 20kHz
power bandwidth	3Hz to 130kHz
dynamic headroom into 4 ohms	2.1 dB
gain	29 dB

Input and Output

input sensitivity for 1 watt	0.1 volts
input sensitivity for 80 watts	0.9 volts
input impedance	49.9 kΩ
damping factor	≥ 350
rise time	1.8 µS

Weight and Dimensions

chassis dimensions	4 1/2” x 17” x 11 3/8” (105mm x 432mm x 289mm)
maximum dimensions	4 3/8” x 17” x 12 1/8” (111mm x 432mm x 308mm)
weight	22 lb. (10.0 kg)
weight, packed	25 lb. (11.3 kg)