Adcom-GFA5400-pwr-sm维修电路图手册.pdf

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1、SERVICE MANUAL 2 CHANNEL POWER AMPLIFIER GFA-5400 TABLE OF CONTENTS Introduction . . . . . . . . . . . . . . . . 1 Version 1 vs. Version 2 . . . . . . . . 1 Test Procedures. . . . . . . . . . . . . 1 Parts List. . . . . . . . . . . . . . . . . . 2 Specifications. . . . . . . . . . . . . . . 6 Chassi

2、s Layout . . . . . . . . . . . . . . . 7 Version 1 Schematic . . . . . . . . . . 8 Version 2 Schematic . . . . . . . . . . 9 10 Timber Lane Marlboro, NJ 07746 USA Tel: 732-683-2356 Fax: 732-683-9790 Web: RadioFans.CN 1 INTRODUCTION This service manual is intended to assist trained and qualified tech

3、nical personnel in verifying the performance of, adjusting, and repairing the ADCOM GFA-5400 amplifier. The procedures described here are not intended for persons unfamiliar with the appropriate safety and test procedures. VERSION 1 vs. VERSION 2 There are 2 versions of the GFA-5400 amplifier. The p

4、rimary difference between the original version 1 and the updated version 2 is the addition of the ADCOM output protection circuit in version 2. This circuit can be noted by comparing the schematics of both versions in this manual. The protection circuit in version 2 includes trigger ICs IC711 and IC

5、712 and a second power supply of standby transformer TT002, rectifier D701 and regulator IC701 that is mounted to a small circuit board at the right front hand side of the unit. The power transformer, speaker binding posts and input jacks are also unique to each version. Besides these distinctions,

6、the amplifier circuit, parts reference numbers and values are nearly identical in both units. Even so, a schematic diagram for both versions is included in this manual. The parts list is for version 2 but contains an addendum section to list parts exclusive to version 1. The board and chassis layout

7、 diagrams are for version 2 only. The alignment procedures are the same for both versions. TEST PROCEDURES All tests are performed 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-pas

8、s filter is employed during THD distortion measurements. Signal-to-noise measurements are “A” weighted. Damping factor is measured 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 r

9、eading the slope of a full power 5kHz square wave. DO NOT OPERATE THE AMPLIFIER AT FULL-POWER SINE WAVE ABOVE 22kHz OR FULL-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 T

10、HE BIAS SETTING AND MUST BE CORRECT TO MAINTAIN THE SONIC QUALITY AND LONGEVITY OF THE AMPLIFIER. BIAS ALIGNMENT and DC OFFSET CHECK Prior to performing BIAS ALIGNMENT and DC OFFSET CHECK turn unit on and allow to run with rated output for approximately 5 MINUTES before attempting adjustments WARNIN

11、G THERE ARE POTENTIALLY LETHAL VOLTAGES WITHIN THE GFA-5400 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-5400 FROM THE WALL AC OUTLET OR OTHER SOURCE OF AC POWER AND THE

12、POWER- SUPPLY CAPACITORS ARE COMPLETELY DISCHARGED. THESE INSTRUCTIONS ARE PROVIDED FOR USE ONLY BY COMPETENT TECHNICAL PERSONNEL. DO NOT UNDERTAKE ANY SERVICE PROCEDURES IN THE GFA-5400 UNLESS YOU ARE TECHNICALLY QUALIFIED TO DO SO. IMPORTANT BEFORE PROCEEDING WITH ADJUSTMENTS, MAKE SURE AMPLIFIER

13、IS AT ROOM TEMPERATURE. RadioFans.CN 2 Step CouplingAdjustAdjust For Plus LeadMinus Lead 1R675R675VR603DC Voltmeter 2R676R676VR604reads 35mV 3L SPKR +L SPKR -VR601DC Voltmeter 4R SPKR +R SPKR -VR602reads 0mV aaaa GFA-5400 SERVICE PARTS LIST Power Supply PCB AF608615 SCHEMATICADCOM PART NUMBERDESCRIP

14、TION LOCATION C901-C90412005565CAPACITOR ELECTROLYTIC 12000uF 63V C905-C90812001185CAPACITOR MP0.1uF 250V C909-C91212005420CAPACITOR ELECTROLYTIC 1000uF 16V C913-C91612005195CAPACITOR ELECTROLYTIC 470uF 100V C917-C92012001185CAPACITOR MP0.1uF 250V D903-D91416004003DIODE1N4003 R901-R90427001590RESIST

15、OR5.6K 1W MOF R905-R91227005030RESISTOR ROED.10 1/2W FUSABLE R913-R91627003280RESISTOR ROED.8.2K 2W 5% METAL TH901, TH90231000512THERMISTORSCK0512 Amplifier PCB AF608625, AF608635 SCHEMATICADCOM PART NUMBERDESCRIPTION LOCATION C601,C60212003175CAPACITOR STYROL390pF 125V C603,C60412001260CAPACITOR MP

16、2.2uF 100V C605,C60612005470CAPACITOR ELECTROLYTIC 47uF 100V C607,C60812001020CAPACITOR LAYER1uF 50V C609,C61012005325CAPACITOR ELECTROLYTIC 4.7uF 50V C611,C61212005280CAPACITOR ELECTROLYTIC 47uF 50V C613,C61412001410CAPACITOR STYROL47pF 125V C615,C61612001285CAPACITOR MYLAR0.1uF 100V C617,C61812001

17、420CAPACITOR STYROL22pF 125V C711,C71212005090CAPACITOR ELECTROLYTIC 10uF 25V C713,C71412002070CAPACITOR CERAMIC0.01uF 50V C715,C71612005040CAPACITOR ELECTROLYTIC 22uF 50V C717,C71812005080CAPACITOR ELECTROLYTIC 100uF 16V D601-D60416000082DIODERD8.2JS-T1 D607-D61616000082DIODERD8.2JS-T1 D711,D712160

18、04003DIODE1N4003 F601-F60419000500FUSE5A 250V IC711, IC71221005550TIMER ICNJM555D Q601-Q60433002100TRANSISTORIRFD210 Q605,Q60633000610TRANSISTORIRF610 Q607,Q60833009210TRANSISTORIRFD9210 RadioFans.CN 3 SCHEMATICADCOM PART NUMBERDESCRIPTION LOCATION Q609,Q61033009610POWER TRANSISTORIRF9610 Q611,Q6123

19、3002100TRANSISTORIRFD210 Q613,Q61433000610POWER TRANSISTORIRF610 Q615-Q62033002400 *(See Note 1)POWER TRANSISTORIRFP240 Q621-Q62633000924 *(See Note 1)POWER TRANSISTORIRFP9240 Q627-Q63033001016TRANSISTOR2SA1016G Q631-Q63433002362TRANSISTOR2SC2362F Q635-Q63833001016TRANSISTOR2SA1016G Q711,Q7123300227

20、4TRANSISTOR2SC2274E Q713,Q71433003478TRANSISTOR2SC3478T Q715,Q71633001016TRANSISTOR2SA1016G Q717,Q71833003478TRANSISTOR2SC3478T R601,R60227001565RESISTOR ROED.221 1/4W 1% R603-R60627002480RESISTOR ROED.1.82K 1/4W 1% R607-R61027004061RESISTOR ROED.51K 1/4W 1% R611,R61227002240RESISTOR ROED.7.5K 1/4W

21、1% R613,R61427002025RESISTOR ROED.1.54K 1/4W 1% R617,R61827002170RESISTOR ROED.470 1/4W 1% R619, R62027002030RESISTOR ROED.10K 1/4W 1% R623,R62427002030RESISTOR ROED.10K 1/4W 1% R625,R62627004290RESISTOR ROED.18.2K 1/4W 1% R627-R63027001565RESISTOR ROED.221 1/4W 1% R631-R63427001565RESISTOR ROED.221

22、 1/4W 1% R635,R63627004061RESISTOR ROED.51K 1/4W 1% R637,R63827001515RESISTOR ROED.4.75 1/4W 1% R639-R64227002010RESISTOR ROED.100 1/4W 1% R643,R64427001530RESISTOR ROED.2.74K 1/4W 1% R645,R64627002030RESISTOR ROED.10K 1/4W 1% R647-R65027002410RESISTOR ROED.4.7K R651-R65427001520RESISTOR ROED.68 R65

23、5-R67027001565RESISTOR ROED.221 R671,R67227002095RESISTOR ROED.2.21K R673,R67427001590RESISTOR5.6K 1W MOF R675-R68627003155RESISTOR0.56 3W MOF R687,R68827004475RESISTOR5.6 2W MOF R691,R69227002020RESISTOR ROED.1K 1/4W 1% R693-R69627002010RESISTOR ROED.100 1/4W 1% R711,R71227002030RESISTOR ROED.10K 1

24、/4W 1% R713,R71427002095RESISTOR ROED.2.21K 1/4W 1% R715,R71627001090RESISTOR220K 5% R717,R71827002020RESISTOR ROED.1K 1/4W 1% R719,R72027002200RESISTOR ROED.4.99K 1/4W 1% R721,R72227002440RESISTOR ROED.33.2K 1/4W 1% R723,R72427002365RESISTOR ROED.49.9K 1/4W 1% R725,R72627001530RESISTOR ROED.2.74K 1

25、/4W 1% R729,R73027002150RESISTOR ROED.3.32K 1/4W 1% S601, S60232005400THERMAL BREAKER (85C) VR601-VR60435001225POTENTIOMETERBOARD MOUNT 4.7K RadioFans.CN 4 Power Switch PCB AF608645 SCHEMATICADCOM PART NUMBERDESCRIPTION LOCATION C92112005700SPARK KILLER 4700pFKC472M C92212001605MOV (120V operation)T

26、NR12G241K C92212001615MOV (240V operation)TNR12G431K PW90137001325POWER SWITCH TH90331002512THERMISTORSCK2R512 Protection Circuit Power Supply PCB AF608665 SCHEMATICADCOM PART NUMBERDESCRIPTION LOCATION C70112005070CAPACITOR ELECTROLYTIC 1000uF 35V C70212005120CAPACITOR ELECTROLYTIC 220uF 16V D70116

27、001530BRIDGE F70119000100FUSE1A 250V IC70121007800REGULATOR ICNJM7812A TT00224005002STANDBY TRANSFORMER Other Hardware SCHEMATICADCOM PART NUMBERDESCRIPTION LOCATION D901,D90216001540BRIDGE RECTIFIERMP154 F00119000800FUSE (120VAC operation)8A 250V F00119000400FUSE (240VAC operation)4A 250V 20005200F

28、USE HOLDER D001, D00216001204THERMAL LED (Red)LTL-1204A 16001204POWER LED (Red)LTL-1204A 16001254DISTORTION LED (Yellow)LTL-1254A 11001155PLASTIC POWER BUTTON 11001040BUTTON SPRING 11001165BUTTON MOUNTING RING 11001170CLEAR BUTTON INSERT 15001050POWER CORD 15001150CORD STOPPER 13005403PRINTED REAR C

29、HASSIS 24005401POWER TRANS. (VER. 2) 22001170INPUT JACK (VER. 2) 13005400TOP COVER 13001020FOOT 30005800SPEAKER POST (VER. 2) 13005401FRONT PANEL RadioFans.CN 5 PARTS EXCLUSIVE TO VERSION ONE OF THE GFA-5400 (VERSION WITHOUT STANDBY POWER SUPPLY AND LM 555 PROTECTION CIRCUITRY) SCHEMATICADCOM PART N

30、UMBERDESCRIPTION LOCATION D605,D60616000082DIODE8.2V ZENER R615,R61627004300RESISTOR15K R621,R62227004200RESISTOR10K PJ1,PJ222001370INPUT JACK, Board Mount 30001045SPEAKER POST RED 30001035SPEAKER POST BLACK Q639,Q64033002362TRANSISTOR2SC2362 T124005400POWER TRANSFORMER * Note 1: Matched IRFP240 and

31、 IRFP9240. Due to manufacturing variations in the turn on voltage of these devices, these parts must be replaced in matched sets of 3. If any one of the output devices fails, all three must be replaced. For example, if Q616 fails in the right channel, then all 3 of the N-channel IRFP240 devices must

32、 be replaced in that channel (Q616, Q618, Q620). When ordering these parts, specify a matched set of 3. Failure to use matched devices will cause current hogging by one of the output devices. Proper bias alignment will not be possible in this circumstance leading to incorrect and, possibly, unreliab

33、le operation. RadioFans.CN 6 aaaa GFA-5400 SPECIFICATIONS Power Rating (To FTC Requirements) 125 watts continuous average power per channel into 8 ohms at any frequency between 20Hz to 20kHz with all channels driven at less than 0.18% THD 200 watts continuous average power per channel into 4 ohms at

34、 any frequency between 20Hz to 20kHz with all channels driven at less than 0.18% THD IM Distortion (SMPTE) 1 watt to 125 watts into 8 ohms . 0.05% 1 watt to 200 watts into 4 ohms . 0.05% IM Distortion (CCIF, Any Combination from 4kHz to 20kHz) 125 watts into 8 ohms. 0.035% 200 watts into 4 ohms. 0.0

35、35% THD + Noise at 130 watts into 8 ohms (Typical) 20Hz. 0.018% 1kHz . 0.02% 10kHz . 0.07% 20kHz . 0.14% THD + Noise at 200 watts into 4 ohms (Typical) 20Hz. 0.018% 1kHz . 0.02% 10kHz . 0.08% 20kHz . 0.165% Frequency Response 1 Watt into 8 ohms (10Hz to 20kHz) . +0, -0.25dB Power Bandwidth (-3dB). 3

36、Hz to 130kHz Dynamic Headroom into 4 ohms . 1.7 dB Signal to Noise Ratio, “A” Weighted (125 watts into 8 ohms). 100dB Gain. 29dB Input Sensitivity for 1 Watt. 0.1 volts for 125 Watts . 1.125 volts Input Impedance. 49.9K Damping Factor (20Hz to 20kHz) . 500 Rise Time (5kHz, 90V, peak-to-peak square wave, 20% to 80%). . 1.9S Power Consumption (Continuous, All Channels Driven) Quiescent . 150VA Maximum. 960VA 125 watts into 8 ohms. 580VA 200 watts into 4 ohms. 920VA Power (Available in 230VAC on special order). 115VAC - 50/60Hz Chassis Dimensions.