Adcom-GFA5002-pwr-sm维修电路原理图.pdf

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1、 SERVICE MANUAL 2 CHANNEL POWER AMPLIFIER GFA-5002 TABLE OF CONTENTS Introduction . . . . . . . . . . . . . . . . . . 1 Test Procedures . . . . . . . . . . . . . . 1 Parts List . . . . . . . . . . . . . . . . . . . . 2 Voltage Conversion . . . . . . . . . . . . 6 Specifications . . . . . . . . . . .

2、 . . . . . 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: RadioFans.CN 收音机爱好者资料库 1 INTRODUCTION This service manual is

3、intended to assist trained and qualified technical personnel in verifying the performance of, adjusting, and repairing the ADCOM GFA-5002 amplifier. The procedures described here are not intended for persons unfamiliar with the appropriate safety and test procedures. TEST PROCEDURES All tests are pe

4、rformed with a 115V, low-distortion (less than 2% THD), AC-power source, 8-ohm resistive load (except slew rate), and a signal source of not more than 600 ohms. An 80kHz low-pass filter is employed during THD distortion measurements. Signal-to-noise measurements are “A” weighted. Damping factor is m

5、easured by comparing the 1 watt output voltage with and without an 8 ohm load. Slew rate is measured with an inductive load, and is derived with a dual-time-based oscilloscope reading the slope of a full power 5kHz square wave. DO NOT OPERATE THE AMPLIFIER AT FULL-POWER SINE WAVE ABOVE 22kHz OR FULL

6、-POWER SQUARE WAVE ABOVE 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 p

7、erforming BIAS ALIGNMENT turn unit on and allow to idle with rated output (8 ohm) for approximately 5 MINUTES before attempting adjustments Step CouplingAdjustAdjust For Plus LeadMinus Lead 1TP3TP1VR603DC Voltmeter 2TP4TP2VR604reads 10mV WARNING THERE ARE POTENTIALLY LETHAL VOLTAGES WITHIN THE GFA-5

8、002 AMPLIFIER WHICH WILL BE ACCESSIBLE ONCE ITS TOP COVER IS REMOVED. DO NOT ATTEMPT FAMILIARIZATION, INSPECTION, OR ANY PROCEDURE WHATSOEVER UNLESS YOU HAVE DISCONNECTED THE GFA-5002 FROM THE WALL AC OUTLET OR OTHER SOURCE OF AC POWER AND THE POWER-SUPPLY CAPACITORS ARE COMPLETELY DISCHARGED. THESE

9、 INSTRUCTIONS ARE PROVIDED FOR USE ONLY BY COMPETENT TECHNICAL PERSONNEL. DO NOT UNDERTAKE ANY SERVICE PROCEDURES IN THE GFA-5002 UNLESS YOU ARE TECHNICALLY QUALIFIED TO DO SO. IMPORTANT BEFORE PROCEEDING WITH ADJUSTMENTS, MAKE SURE AMPLIFIER IS AT ROOM TEMPERATURE. RadioFans.CN 收音机爱好者资料库 2 a GFA-5

10、002 SERVICE PARTS LIST Amplifier PCB AF705514 and AF705524 Schematic Part Number Description Location C603, C604 12001260 Capacitor 2.2F 100V C607, C608 12001400 Capacitor 1F 100V C609, C610 12005470 Capacitor 47F 100V Electrolytic C611, C612 12001420 Capacitor 22pF 125V C613, C614 12003070 Capacito

11、r 39pF 125V C615, C616 12005325 Capacitor 4.7F 50V Electrolytic C617-C620 12003080 Capacitor 68pF 125V C621, C622 12001450 Capacitor 0.22F 100V C623, C624 12001170 Capacitor 0.1F 100V C625,C626 12001450 Capacitor 0.22F 100V C901-C904 12005450 Capacitor 6800F 63V Electrolytic D001,D002 16001254 Disto

12、rtion LED (Yellow) LTL-1254 D003,D004 16001204 Thermal LED (Red) LTL-1204 D601-D608 16004148 Diode 1N4148 D610-D613 16003001 Diode DSC30TC D801,D802 16004148 Diode 1N4148 D901,D902 16008030 Bridge Rectifier PBPC903 F601-F604 19009400 Fuse 4A 250V Q601-Q606 33002362 NPN Transistor 2SC2362K Q607,Q608

13、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-

14、T Q621,Q622 33001376 PNP Transistor 2SA1376L-T Q623,Q624 33003902 NPN Transistor 2SC3902 Q625,Q626 33001507 PNP Transistor 2SA1507 Q627,Q628 33001047 NPN Transistor 2SD1047 Q629,Q630 33008170 PNP Transistor 2SB817 Q631,Q632 33001047 NPN Transistor 2SD1047 Q633,Q634 33008170 PNP Transistor 2SB817 Q80

15、1,Q802 33001016 PNP Transistor 2SA1016F-T R603,R604 27004260 Resistor 2.74K 1%MF R605,R606 27004135 Resistor 4.99K 1%MF R607,R608 27004050 Resistor 1K 1%MF R609,R610 27004120 Resistor 22.1K 1%MF R611,R612 27004420 Resistor 33.2 1%MF R613,R614 27004350 Resistor 825 1%MF R615,R616 27004225 Resistor 47

16、5 1%MF R617, R618 27004140 Resistor 332 1%MF R619,R620 27004160 Resistor 47.5K 1%MF R621,R622 27004120 Resistor 22.1K 1%MF R623,R624 27001550 Resistor 121 1%MF 3 R625,R626 27004330 Resistor 5.62K 1%MF Schematic Part Number Description Location R627,R628 27004225 Resistor 475 1%MF R629,R630 27004420

17、Resistor 33.2 1%MF R631,R632 27004260 Resistor 2.74K 1%MF R633,R634 27004540 Resistor 499 1%MF R635-R638 27004235 Resistor 68.1 1%MF R639-R642 27004320 Resistor 47.5 1%MF R643-R650 27004170 Resistor 10 1%MF R651,R652 27004140 Resistor 332 1%MF R653,R654 27004120 Resistor 22.1K 1%MF R655,R656 2700461

18、0 Resistor 22.1 1%MF R657-R664 27001500 Resistor 0.33 R665,R666 27003035 Resistor 5.1 (2W) R667,R668 27004650 Resistor 750 1%MF R669,R670 27004455 Resistor 133 1%MF R671,R672 27004120 Resistor 22.1K 1%MF R673,R674 27004200 Resistor 10K 1%MF R675,R676 27003105 Resistor 1 (1W) R801,R802 27004670 Resis

19、tor 100 1%MF R803, R804 27004120 Resistor 22.1K 1%MF R805,R806 27004320 Resistor 47.5 1%MF R807,R808 27004090 Resistor 121K 1%MF R901-R904 27001590 Resistor 5.6K (1W) S601,S602 32005400 Thermal Breaker B-1002B VR603,VR604 35001090 Bias Pot SFKPV220R Protection PCB AF705534 Schematic Part Number Desc

20、ription Location C801 12005100 Capacitor 10F 50V Electrolytic C802-C804 12005610 Capacitor 33F 50V Electrolytic C701, C702 12005640 Capacitor 0.22F 50V Electrolytic C703 12005610 Capacitor 33F 50V Electrolytic C704 12005020 Capacitor 100F 25VElectrolytic C705 12002020 Capacitor 0.01F 50V C706 120056

21、10 Capacitor 33F 50V Electrolytic C707 12005610 Capacitor 33F 50V Electrolytic C905, C906 12005070 Capacitor 1000F 35V Electrolytic C907, C908 12005130 Capacitor 220F 25V Electrolytic C909 12005360 Capacitor 100F 50V Electrolytic C910 12005700 Capacitor 4700pF 250V D701-D706 16004148 Diode 1N4148 D7

22、07 16004003 Diode 1N4003 D803 16004003 Diode 1N4003 D804 16004148 Diode 1N4148 D903 16001530 Bridge Rectifier W-02G D904 16004148 Diode 1N4148 4 D905 16004003 Diode 1N4003 F902 19009100 Fuse 1A 250V Schematic Part Number Description Location IC701,IC702 21004558 Dual Op-Amp NJM4558DD IC703 21005550

23、Timer IC NJM555D IC801 21001237 Protect IC UPC1237H IC901 21007912 Regulator IC NJM7912 IC902 21007800 Regulator IC NJM7812 PT902 24005002 Standby Transformer TT-345-U Q701,Q702 33005360 NPN Transistor 2SC536G-T Q703 33006000 NPN Transistor 2SD600KE Q704 33003399 Digital NPN Transistor 2SC3399-T R70

24、1,R702 27004200 Resistor 10K R703,R704 27004210 Resistor 100K R705,R706 27004630 Resistor 221K R707,R708 27004400 Resistor 1.82K R709-R711 27004210 Resistor 100K R712,R713 27004465 Resistor 909K R714,R715 27004200 Resistor 10K R716 27004210 Resistor 100K R717 27004070 Resistor 2.21K R718 27004530 Re

25、sistor 1.21K R719 27004600 Resistor 4.75K R720,R721 27004120 Resistor 22.1K R809 27004290 Resistor 18.2K R810 27001590 Resistor 5.6K (1W) R811 27004485 Resistor 82.5K R812 27003150 Resistor 820 (1W) R813 27004210 Resistor 100K R905 27003095 Resistor 33 (1W) RY801 28001140 Relay VB-24SMCU-E RY901 280

26、01150 Relay G4W-1112P-VD Input PCB AF705544 Schematic Part Number Description Location C601, C602 12001390 Capacitor 125V 330pF JP601, JP602 22001020 RCA Jack 4TR-2709-3 R601,R602 27004050 Resistor 1K SW601 37001350 Bridging Switch SX4TR-2886 VR601,VR602 35005002 Input Level Pot 4TR-3379 DC Trigger

27、Board AF705554 Schematic Part Number Description Location 5 JP701 22001570 DC Trigger Input Jack YK-5103A SW901 37005006 Ground Switch SS004-P022 Other Hardware Schematic Part Number Description Location 30005002 Speaker Binding Post 4TR-3357 19000500 Fuse - 115V Models (U.S.) 5A 125V 19008250 Fuse

28、- 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

29、TFP-824 11005002 LED Ring (for Power LED) 4TR-2209B#1 9F 13005003 Top Cover 3TQA-5 15001110 AC Power Chord 115V (U.S.) 4TR-3403 SJT AWG16 6 a GFA-5002 Voltage Conversion 115V to 230V 1) Unplug the power cord and remove the top cover. 2) Locate the standby transformer, PT902, on the circuit board in

30、the middle of the unit. 3) Near PT902, cut jumpers J1, J2, J4, J5 - see figure 1 below. 4) Make jumpers J3 and J6 - see figure 1 below. 5) Change the rear panel fuse to 2.5A 250V and place a 2.5A sticker above the fuse holder so that the new value is indicated. Figure 1: Jumper position for 230V ope

31、ration. 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.

32、 5) Change the rear panel fuse to 5A 250V and place a 5A sticker above the fuse holder so that the new value is indicated. Figure 2: Jumper position for 115V operation. Main fuse is 5A 250V. PT902 F902 RY901 J3 230V J2 115V 115V J5 115V J1 J6 230V 115V J4 PT902 F902 RY901 J3 230V J2 115V 115V J5 115

33、V J1 J6 230V 115V J4 7 a GFA-5002 SPECIFICATIONS Power Rating (To FTC Requirements) 50 watts continuous average power per channel into 8 ohms at any frequency between 20Hz to 20kHz with all channels driven at less than 0.05% THD 75 watts continuous average power per channel into 4 ohms at any freque

34、ncy between 20Hz to 20kHz with all channels driven at less than 0.05% THD Bridged Power: 175 watts continuous average power (one channel) into 8 ohms at any frequency between 20Hz to 20KHz with less than 0.09% THD IM Distortion (SMPTE) 1 watt to 50 watts into 8 ohms. 0.05% 1 watt to 75 watts into 4

35、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” Weight

36、ed (50 watts into 8 ohms). 100dB Gain. 29dB Input Sensitivity . variable Input Impedance. 17k Damping Factor (20Hz to 20kHz). 400 Rise Time (5kHz, 90V, peak-to-peak square wave, 20% to 80%). 2.7S Power Consumption (Continuous, All Channels Driven) Quiescent. 30VA Maximum. 600VA Power (Available in 230VAC on special order). 115VAC - 50/60Hz Chassis Dimensions. 3” x 17” x 11.5” Maximum Dimensions. 3.5” x 17” x 12.5” Weight. 18lb Weight, Packed. 21lb