Adcom-GFA5400-pwr-sm维修电路原理图.pdf

SERVICE MANUAL2 CHANNELPOWER AMPLIFIERGFA-5400TABLE OF CONTENTSIntroduction . . . . . . . . . . . . . . . . 1Version 1 vs. Version 2 . . . . . . . . 1Test Procedures. . . . . . . . . . . . . 1Parts List. . . . . . . . . . . . . . . . . . 2Specifications. . . . . . . . . . . . . . . 6Chassis Layout . . . . . . . . . . . . . . . 7Version 1 Schematic . . . . . . . . . . 8Version 2 Schematic . . . . . . . . . . 910 Timber LaneMarlboro, NJ 07746USATel: 732-683-2356Fax: 732-683-9790Web: http:/RadioFans.CN 收音机爱 好者资料库1INTRODUCTIONThis service manual is intended to assist trained and qualified technical personnel in verifying theperformance of, adjusting, and repairing the ADCOM GFA-5400 amplifier. The procedures describedhere are not intended for persons unfamiliar with the appropriate safety and test procedures.VERSION 1 vs. VERSION 2There are 2 versions of the GFA-5400 amplifier. The primary difference between the original version 1and the updated version 2 is the addition of the ADCOM output protection circuit in version 2. This circuitcan be noted by comparing the schematics of both versions in this manual. The protection circuit inversion 2 includes trigger ICs IC711 and IC712 and a second power supply of standby transformerTT002, rectifier D701 and regulator IC701 that is mounted to a small circuit board at the right front handside of the unit. The power transformer, speaker binding posts and input jacks are also unique to eachversion.Besides these distinctions, the amplifier circuit, parts reference numbers and values are nearly identical inboth units. Even so, a schematic diagram for both versions is included in this manual. The parts list is forversion 2 but contains an addendum section to list parts exclusive to version 1. The board and chassislayout 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-ohmresistive 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 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 oscilloscopereading the slope of a full power 5kHz square wave. DO NOT OPERATE THE AMPLIFIER ATFULL-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 THEBIAS SETTING AND MUST BE CORRECT TO MAINTAIN THE SONIC QUALITY AND LONGEVITYOF THE AMPLIFIER.BIAS ALIGNMENT and DC OFFSET CHECKPrior to performing BIAS ALIGNMENT and DC OFFSET CHECK turn unit on and allow to run with ratedoutput for approximately 5 MINUTES before attempting adjustments WARNING THERE ARE POTENTIALLY LETHAL VOLTAGES WITHIN THE GFA-5400 AMPLIFIER WHICH WILLBE ACCESSIBLE ONCE ITS TOP COVER IS REMOVED. DO NOT ATTEMPT FAMILIARIZATION,INSPECTION, OR ANY PROCEDURE WHATSOEVER UNLESS YOU HAVE DISCONNECTED THEGFA-5400 FROM THE WALL AC OUTLET OR OTHER SOURCE OF AC POWER AND THE POWER-SUPPLY CAPACITORS ARE COMPLETELY DISCHARGED. THESE INSTRUCTIONS AREPROVIDED FOR USE ONLY BY COMPETENT TECHNICAL PERSONNEL. DO NOT UNDERTAKEANY SERVICE PROCEDURES IN THE GFA-5400 UNLESS YOU ARE TECHNICALLY QUALIFIEDTO DO SO.IMPORTANTBEFORE PROCEEDING WITH ADJUSTMENTS, MAKE SURE AMPLIFIER IS AT ROOMTEMPERATURE.RadioFans.CN 收音机爱 好者资料库2Step CouplingAdjustAdjust ForPlus LeadMinus Lead1R675R675VR603DC Voltmeter2R676R676VR604reads 35mV3L SPKR +L SPKR -VR601DC Voltmeter4R SPKR +R SPKR -VR602reads 0mVaaaa GFA-5400 SERVICE PARTS LISTPower Supply PCBAF608615SCHEMATICADCOM PART NUMBERDESCRIPTIONLOCATIONC901-C90412005565CAPACITOR ELECTROLYTIC 12000uF 63VC905-C90812001185CAPACITOR MP0.1uF 250VC909-C91212005420CAPACITOR ELECTROLYTIC 1000uF 16VC913-C91612005195CAPACITOR ELECTROLYTIC 470uF 100VC917-C92012001185CAPACITOR MP0.1uF 250VD903-D91416004003DIODE1N4003R901-R90427001590RESISTOR5.6K 1W MOFR905-R91227005030RESISTOR ROED.10 1/2W FUSABLER913-R91627003280RESISTOR ROED.8.2K 2W 5% METALTH901, TH90231000512THERMISTORSCK0512Amplifier PCBAF608625, AF608635SCHEMATICADCOM PART NUMBERDESCRIPTIONLOCATIONC601,C60212003175CAPACITOR STYROL390pF 125VC603,C60412001260CAPACITOR MP2.2uF 100VC605,C60612005470CAPACITOR ELECTROLYTIC 47uF 100VC607,C60812001020CAPACITOR LAYER1uF 50VC609,C61012005325CAPACITOR ELECTROLYTIC 4.7uF 50VC611,C61212005280CAPACITOR ELECTROLYTIC 47uF 50VC613,C61412001410CAPACITOR STYROL47pF 125VC615,C61612001285CAPACITOR MYLAR0.1uF 100VC617,C61812001420CAPACITOR STYROL22pF 125VC711,C71212005090CAPACITOR ELECTROLYTIC 10uF 25VC713,C71412002070CAPACITOR CERAMIC0.01uF 50VC715,C71612005040CAPACITOR ELECTROLYTIC 22uF 50VC717,C71812005080CAPACITOR ELECTROLYTIC 100uF 16VD601-D60416000082DIODERD8.2JS-T1D607-D61616000082DIODERD8.2JS-T1D711,D71216004003DIODE1N4003F601-F60419000500FUSE5A 250VIC711, IC71221005550TIMER ICNJM555DQ601-Q60433002100TRANSISTORIRFD210Q605,Q60633000610TRANSISTORIRF610Q607,Q60833009210TRANSISTORIRFD9210RadioFans.CN 收音机爱 好者资料库3SCHEMATICADCOM PART NUMBERDESCRIPTIONLOCATIONQ609,Q61033009610POWER TRANSISTORIRF9610Q611,Q61233002100TRANSISTORIRFD210Q613,Q61433000610POWER TRANSISTORIRF610Q615-Q62033002400 *(See Note 1)POWER TRANSISTORIRFP240Q621-Q62633000924 *(See Note 1)POWER TRANSISTORIRFP9240Q627-Q63033001016TRANSISTOR2SA1016GQ631-Q63433002362TRANSISTOR2SC2362FQ635-Q63833001016TRANSISTOR2SA1016GQ711,Q71233002274TRANSISTOR2SC2274EQ713,Q71433003478TRANSISTOR2SC3478TQ715,Q71633001016TRANSISTOR2SA1016GQ717,Q71833003478TRANSISTOR2SC3478TR601,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 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 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.4.7KR651-R65427001520RESISTOR ROED.68R655-R67027001565RESISTOR ROED.221R671,R67227002095RESISTOR ROED.2.21KR673,R67427001590RESISTOR5.6K 1W MOFR675-R68627003155RESISTOR0.56 3W MOFR687,R68827004475RESISTOR5.6 2W MOFR691,R69227002020RESISTOR ROED.1K 1/4W 1%R693-R69627002010RESISTOR ROED.100 1/4W 1%R711,R71227002030RESISTOR ROED.10K 1/4W 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 1/4W 1%R729,R73027002150RESISTOR ROED.3.32K 1/4W 1%S601, S60232005400THERMAL BREAKER (85C)VR601-VR60435001225POTENTIOMETERBOARD MOUNT 4.7KRadioFans.CN 收音机爱 好者资料库4Power Switch PCBAF608645SCHEMATICADCOM PART NUMBERDESCRIPTIONLOCATIONC92112005700SPARK KILLER 4700pFKC472MC92212001605MOV (120V operation)TNR12G241KC92212001615MOV (240V operation)TNR12G431KPW90137001325POWER SWITCHTH90331002512THERMISTORSCK2R512Protection Circuit Power Supply PCBAF608665SCHEMATICADCOM PART NUMBERDESCRIPTIONLOCATIONC70112005070CAPACITOR ELECTROLYTIC 1000uF 35VC70212005120CAPACITOR ELECTROLYTIC 220uF 16VD70116001530BRIDGEF70119000100FUSE1A 250VIC70121007800REGULATOR ICNJM7812ATT00224005002STANDBY TRANSFORMEROther HardwareSCHEMATICADCOM PART NUMBERDESCRIPTIONLOCATIOND901,D90216001540BRIDGE RECTIFIERMP154F00119000800FUSE (120VAC operation)8A 250VF00119000400FUSE (240VAC operation)4A 250V20005200FUSE HOLDERD001, D00216001204THERMAL LED (Red)LTL-1204A16001204POWER LED (Red)LTL-1204A16001254DISTORTION LED (Yellow)LTL-1254A11001155PLASTIC POWER BUTTON11001040BUTTON SPRING11001165BUTTON MOUNTING RING11001170CLEAR BUTTON INSERT15001050POWER CORD15001150CORD STOPPER13005403PRINTED REAR CHASSIS24005401POWER TRANS. (VER. 2)22001170INPUT JACK (VER. 2)13005400TOP COVER13001020FOOT30005800SPEAKER POST (VER. 2)13005401FRONT PANELRadioFans.CN 收音机爱 好者资料库5PARTS EXCLUSIVE TO VERSION ONE OF THE GFA-5400(VERSION WITHOUT STANDBY POWER SUPPLY AND LM 555 PROTECTION CIRCUITRY)SCHEMATICADCOM PART NUMBERDESCRIPTIONLOCATIOND605,D60616000082DIODE8.2V ZENERR615,R61627004300RESISTOR15KR621,R62227004200RESISTOR10KPJ1,PJ222001370INPUT JACK, Board Mount30001045SPEAKER POST RED30001035SPEAKER POST BLACKQ639,Q64033002362TRANSISTOR2SC2362T124005400POWER TRANSFORMER* Note 1: Matched IRFP240 and IRFP9240. Due to manufacturing variations in the turn on voltage ofthese 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-channelIRFP240 devices must 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 theoutput devices. Proper bias alignment will not be possible in this circumstance leading to incorrect and,possibly, unreliable operation.RadioFans.CN 收音机爱 好者资料库6aaaa GFA-5400 SPECIFICATIONSPower Rating (To FTC Requirements)125 watts continuous average power per channel into 8 ohms at any frequency between 20Hz to 20kHz withall channels driven at less than 0.18% THD200 watts continuous average power per channel into 4 ohms at any frequency between 20Hz to 20kHz withall channels driven at less than 0.18% THDIM 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. 0.035%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, -0.25dBPower Bandwidth (-3dB). 3Hz to 130kHzDynamic Headroom into 4 ohms . 1.7 dBSignal to Noise Ratio, “A” Weighted (125 watts into 8 ohms). 100dBGain. 29dBInput Sensitivityfor 1 Watt. 0.1 voltsfor 125 Watts . 1.125 voltsInput Impedance. 49.9KDamping Factor (20Hz to 20kHz) . 500Rise Time (5kHz, 90V, peak-to-peak square wave, 20% to 80%) . . 1.9SPower Consumption (Continuous, All Channels Driven)Quiescent . 150VAMaximum. 960VA125 watts into 8 ohms. 580VA200 watts into 4 ohms. 920VAPower (Available in 230VAC on special order). 115VAC - 50/60HzChassis Dimensions. 5” (127mm) x 17” (432mm) x 11.5” (292mm)Maximum Dimensions . 53/8” (137mm) x 17” (432mm) x 12.5” (375mm)Weight.26 lb. (11.8 kg)Weight, Packed.30 lb. (13.6kg)RadioFans.CN 收音机爱 好者资料库RadioFans.CN 收音机爱 好者资料库