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SERVICE MANUAL 

  

2 CHANNEL 

POWER AMPLIFIER

 

GFA-5002

 

 

TABLE OF CONTENTS 

 

 

 

 

 

 

Introduction . . . . . . . . . . . . . . . . . . 

 

 

 

 

Test Procedures . . . . . . . . . . . . . .  

 

 

 

 

Parts List . . . . . . . . . . . . . . . . . . . . 

 

 

 

 

Voltage Conversion . . . . . . . . . . . . 6 

 

 

 

 

Specifications . . . . . . . . . . . . . . . . 7 

 

 

 

 

PCB Layout . . . . . . . . . . . . . . . . . . 

 

 

 

 

Wiring Diagram . . . . . . . . . . . . . . . 

 

 

 

 

Schematic . . . . . . . . . . . . . . . . . . .10 

 

 

10 Timber Lane 

Marlboro, NJ  07746 

USA 

Tel: 732-683-2356 

Fax: 732-683-9790 

 

Web: http://www.adcom.com 

Summary of Contents for GFA-5002

Page 1: ...A 5002 TABLE OF CONTENTS Introduction 1 Test Procedures 1 Parts List 2 Voltage Conversion 6 Specifications 7 PCB Layout 8 Wiring Diagram 9 Schematic 10 10 Timber Lane Marlboro NJ 07746 USA Tel 732 683 2356 Fax 732 683 9790 Web http www adcom com ...

Page 2: ...VE 5kHz CORRECT BIAS ADJUSTMENT IS CRITICAL TO THE PERFORMANCE OF THIS AMPLIFIER MAXIMUM OUTPUT POWER MINIMUM THD AND HEAT DISSIPATION ARE AFFECTED BY THE BIAS SETTING AND MUST BE CORRECT TO MAINTAIN THE SONIC QUALITY AND LONGEVITY OF THE AMPLIFIER BIAS ALIGNMENT Prior to performing BIAS ALIGNMENT turn unit on and allow to idle with rated output 8 ohm for approximately 5 MINUTES before attempting ...

Page 3: ...2SC2362K Q607 Q608 33001016 PNP Transistor 2SA1016F T Q609 Q610 33001376 PNP Transistor 2SA1376L T Q611 Q612 33009700 PNP Transistor 2SA970B T Q613 Q614 33001376 PNP Transistor 2SA1376L T Q615 Q616 33003478 NPN Transistor 2SC3478L T Q617 Q618 33006000 NPN Transistor 2SD600KE Q619 Q620 33003478 NPN Transistor 2SC3478L T Q621 Q622 33001376 PNP Transistor 2SA1376L T Q623 Q624 33003902 NPN Transistor ...

Page 4: ... 1 MF R805 R806 27004320 Resistor 47 5Ω 1 MF R807 R808 27004090 Resistor 121KΩ 1 MF R901 R904 27001590 Resistor 5 6KΩ 1W S601 S602 32005400 Thermal Breaker B 1002B VR603 VR604 35001090 Bias Pot SFKPV220R Protection PCB AF705534 Schematic Part Number Description Location C801 12005100 Capacitor 10µF 50V Electrolytic C802 C804 12005610 Capacitor 33µF 50V Electrolytic C701 C702 12005640 Capacitor 0 2...

Page 5: ...istor 100KΩ R712 R713 27004465 Resistor 909KΩ R714 R715 27004200 Resistor 10KΩ R716 27004210 Resistor 100KΩ R717 27004070 Resistor 2 21KΩ R718 27004530 Resistor 1 21KΩ R719 27004600 Resistor 4 75KΩ R720 R721 27004120 Resistor 22 1KΩ R809 27004290 Resistor 18 2KΩ R810 27001590 Resistor 5 6KΩ 1W R811 27004485 Resistor 82 5KΩ R812 27003150 Resistor 820 Ω 1W R813 27004210 Resistor 100KΩ R905 27003095 ...

Page 6: ... Fuse 230V Models Euro 2 5A 250V 24005003 Transformer TT 342 U 37005002 Vacation Switch R19 33FM2 2N 16002249 POWER STANDBY LED VRPY3349S 25001060 AC Inlet 4TR 2786 13005004 Printed Rear Chassis TRP 750A 13001020 Foot 4TR 2823 1 24FX14H 47005002 Alum Shield Board 4TR 3400 13005002 Front Panel 3TOZ 1 TFP 824 11005002 LED Ring for Power LED 4TR 2209B 1 9F 13005003 Top Cover 3TQA 5 15001110 AC Power ...

Page 7: ...r position for 230V operation Main fuse is 2 5A 250V 230V to 115V 1 Unplug the power cord and remove the top cover 2 Locate the standby transformer PT902 on the circuit board in the middle of the unit 3 Near PT902 cut jumpers J3 and J6 see figure 2 below 4 Make jumpers J1 J2 J4 and J5 see figure 2 below 5 Change the rear panel fuse to 5A 250V and place a 5A sticker above the fuse holder so that th...

Page 8: ... 8 ohms 0 05 1 watt to 75 watts into 4 ohms 0 05 IM Distortion CCIF Any Combination from 4kHz to 20kHz 50 watts into 8 ohms 0 01 75 watts into 4 ohms 0 01 Frequency Response 1 Watt into 8 ohms 10Hz to 20kHz 0 0 25dB Power Bandwidth 3dB 5Hz to 130kHz Dynamic Headroom into 4 ohms 1 8 dB Signal to Noise Ratio A Weighted 50 watts into 8 ohms 100dB Gain 29dB Input Sensitivity variable Input Impedance 1...

Page 9: ...a ...

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