Mackie-M1200-pwr-sm 维修电路原理图.pdf

M1400 / M1400i / M1200SERVICE MANUAL1998 MACKIE DESIGNS, INC.820-179-00 Version 1.2RadioFans.CN 收音机爱 好者资料库Go To BulletinsPage 3 is interactive CAUTION AVIS RISK OF ELECTRIC SHOCKDO NOT OPENRISQUE DE CHOC ELECTRIQUENE PAS OUVRIRCAUTION: TO REDUCE THE RISK OFELECTRIC SHOCK DO NOT REMOVETHE COVERNO USER SERVICEABLE PARTS INSIDEREFER SERVICING TO QUALIFIEDPERSONNELWARNING: TO REDUCE THE RISK OFFIRE OR ELECTRIC SHOCK, DO NOTEXPOSE THIS PRODUCT TO RAIN ORMOISTURETO PREVENT ELECTRIC SHOCK, DONOT USE THIS POLARIZED PLUG WITHAN EXTENSION CORD, RECEPTACLE OROTHER OUTLET UNLESS THE BLADESCAN BE FULLY INSERTED TO PREVENTBLADE EXPOSURE.ATTENTION: POUR EVITER LESRISQUES DE CHOC ELECTRIQUE, NEPAS ENLEVER LE COUVERCLE. AUCUNENTRETIEN DE PIECES INTERIEURESPAR LUSAGER. CONFIER LENTRETIENAU PERSONNEL QUALIFIE.AVIS:POUR EVITER LES RISQUESDINCENDIE OU DELECTROCUTION,NEXPOSEZ PAS CET ARTICLE A LAPLUIE OU A LHUMIDITE.POUR PREVENIR LES CHOCSELECTRIQUES NE PAS UTILISER CETTEFICHE POLARISEE AVEC UNPROLONGATEUR, UN PRISE DECOURANT OU UNE AUTRE SORTIE DECOURANT, SAUF SI LES LAMESPEUVENT ETRE INSEREES A FONDSANS LAISSER AUCUNE PARTIE ADECOUVERT.The lightning flash with arrowhead symbol within anequilateral triangle is intended to alert the user to thepresence of uninsulated dangerous voltage within theproducts enclosure, that may be of sufficient magnitude toconstitude a risk of electric shock to persons.Le symbole clair avec point de flche linterieur duntriangle quilatral est utilis pour alerter lutilisateur de laprsence linterieur du coffret de vlotage dangereux nonisole dampleur suffisante pour constituer un risquedlctrocution. The exclamation point within an equilateral triangleis intended to alert the user to the presence ofimportant operating and maintenance (servicing)instructions in the literature accompanying theappliance.Le point dexclamation lintrieur dun triangle dela prsence dinstructions importantes pour lefonctionnement et lentretien (service) dans le livretdinstrucion accompagnant Lappareil.CAUTION AVISRadioFans.CN 收音机爱 好者资料库TABLE OF CONTENTSINTRODUCTION. 2SYSTEM OVERVIEW. 3SUMMARY OF FEATURES .4SPECIFICATIONS.6CIRCUIT THEORY. 8INPUT CIRCUITRY.8POWER AMPLIFIER CIRCUITRY.8PROTECTION CIRCUITS .9THERMAL MANAGEMENT.10SERVICE PROCEDURES.11REQUIRED EQUIPMENT LIST .11TROUBLESHOOTING TIPS - OUTPUT FAILURES.12TEST AND BIASING PROCEDURE.13PARTS.15QUICK PARTS .15CHASSIS ASSEMBLY.16HEATSINK ASSEMBLY.18COMPLETE PARTS LIST.20SCHEMATICS / PCB LAYOUTS.23INPUT PCB SCHEMATIC.23INPUT PCB LAYOUT.24DISPLAY PCB SCHEMATIC.25DISPLAY PCB LAYOUT.26MAIN PCB SCHEMATICS.27MAIN PCB LAYOUT .30SOFT START PCB SCHEMATIC.31SOFT START PCB LAYOUT.32Click on any item to open that pageM1200/M1400 SERVICE MANUALINTRODUCTION2INTRODUCTIONThis manual contains complete service information for the M1200, M1400 and M1400iaudio power amplifiers. Operating instructions will be touched on briefly. For completeoperating instructions refer to the owners manual.The FR Series M1200 and M1400 are high power audio amplifiers designed forprofessional applications. They feature audiophile quality sound, excellent stability,extensive protection circuitry, and legendary Mackie reliability. Patented Fast Recoverycircuitry allows the M1200/M1400 to recover from clipping without generatingundesirable artifacts.To service the M1200/M1400, technicians should be familiar with op-amps, discreteanalog circuitry, and troubleshooting high power solid state amplifiers. Presentation ofthis manual does not constitute endorsement of qualifications by Mackie Designs.TECHNICAL SUPPORTMackie Designs Technical Support Department is available 8AM - 5PM PST, Monday -Friday at 1-800-258-6883 (outside US call 011-425-487-4333) Please feel free to call withany questions (Better safe than sorry!).DISCLAIMERThe information contained in this manual is proprietary to Mackie Designs, Inc. Theentire manual is protected under copyright and may not be reproduced by any meanswithout express written permission from Mackie Designs, Inc.SERVICE ON THE M1200/M1400 ISTO BE PERFORMED BY EXPERIENCEDTECHNICIANS ONLY! SMD !The M1200/M1400 makes extensiveuse of surface mount components.Servicing technicians should have thetools and experience to performsurface mount rework.VERSION 1.1SYSTEM OVERVIEW3SYSTEM OVERVIEWThis section provides a quick summary of the M1200/M1400s major features. It is notintended to take the place of the owners manual. It is included here to help servicingtechnicians familiarize themselves with the M1200/M1400.DIFFERENCES BETWEEN THE M1400, M1400i AND M1200The M1200 and M1400 are electronically identical products with the followingexceptions:1. The M1400 has 12,000uF main filter caps, where the M1200 and M1400i have10,000uF.2. The M1400 and M1400i use a more powerful fan than the M1200.3. The M1400 has Speakon connectors where the M1200 and M1400i have ”speaker outputs (both in addition to binding posts).The M1200 was discontinued in 1998 and replaced by the M1400i.Export M1400s also have a “Soft Start” circuit that is not installed on American units.FAST RECOVERY DESIGNSolid state power amplifiers have a reputation for sounding harsh when driven intoclipping. The usual explanation is odd harmonics generated by hard clipping, but Infact much of the unpleasant sound is caused by latching and parasitic oscillations thatoccur as the amplifier recovers from clipping.TYPICAL AMPLIFIERMACKIE FR SERIESARTIFACTS CAUSED BYLATCHING AND PARASITICOSCILLATIONMackies Fast Recovery design recovers from clipping quickly without generating anyundesirable artifacts. This performance is achieved by two unique design elements; theFull Symmetry Dual Differential front end provides excellent linearity while minimizing theneed for negative feedback, and the Baker Clamp prevents output/driver devicesaturation. How these circuits operate is covered in depth in the circuit theory section.M1200/M1400 SERVICE MANUALSUMMARY OF FEATURES4SUMMARY OF FEATURESFRONT PANEL1. GAINDetented gain controls adjust the level sent to each output section. The gain structureis designed so that a +4dBu (1.23V rms) input signal drives the amplifier to full ratedpower into 4.2. METERSThe M1200/M1400s meters indicate the relative output level of the amplifierreferenced to full power. The SIG (signal present) senses the input prior to the gaincontrol.3. PROTECTThe Protect LEDs light indicating the channel has been muted for one of the followingreasons: 4 second turn on delay Output devices beyond Safe Operating Area (SOA), also lights SHORT LED(s). Heatsink temperature beyond 80 degrees Celsius.4. SHORTThe Short LEDs light to show that the amplifier has engaged protection due to a short orlow impedance on the output.5. TEMP STATUSThe HOT LED lights to indicate that the amplifier has engaged protection due toheatsink temperature or power transformer core temperature.6. POWER SWITCHThis remarkable device requires years of study to full comprehend.OL- 3- 6- 20-3-6-9- 20SIGOLSIGCH130282620221824161481.23v (+4dBu)SENSITIVITYGAIN /dBCH2PROTECTCOLDHOTSHORTTEMP ST ATUSINTERNALSTATUSCH1CH2CH 1& 2ONOFFPOWER3v2v1 v30282620221824161481.23v (+4dBu)SENSITIVITYGAIN/dB3v2v1 v PROFESSIONAL POWER AMPLIFIERFULL SYMMETRY DUAL DIFFERENTIAL HIGH CURRENT DESIGN - 91123456VERSION 1.1SYSTEM OVERVIEW5REAR PANEL1. SPEAKER OUTPUTSThe M1400 has Speakon connectors where the M1200 has ” speaker outputs. Bothmodels have binding posts. For bridged mono operation, the + output comes fromchannel ones positive terminal and - from channel twos positive.2. INPUTThe M1200/M1400 has both XLR and ” TRS inputs. They are electrically identical(wired in parallel). In bridged mono or parallel mono mode channel 2 input is disabled.3. THROUGHYet another jack wired in parallel with the Inputs, the through jack provides aconvenient way to chain amplifiers or pass the signal to any other device.4. LOW CUT FILTERSweeps the built in high pass filter from 10Hz to 170Hz.5. CONSTANT DIRECTIVITY HORN EQ/AIR EQBuilt in shelving EQ provides high frequency compensation when using constantdirectivity horns.6. AMP MODEThree position slide switch selects STEREO, PARALLEL MONO or BRIDGE MONO operation.Channel Ones input signal is used for PARALLEL MONO and BRIDGE MONO operation.AMP MODE and OUTPUT APPLICATION switches should not be changed while the unit ison.7. OUTPUT APPLICATIONPlacing the three position slide switch in its center position defeats the built in LIMITER forboth channels. Selecting SUB WOOFER engages the built in low pass filter. TheFREQUENCY switch selects between 125Hz and 63Hz cutoff for the low pass filter. In SUBWOOFER mode, inputs 1 and 2 are summed regardless of AMP MODE setting.(Remember, human hearing is unable to discern direction at frequencies where thewavelenth is greater than the distance between your ears, 250Hz unless you have agrossly large head!)CHA N NE L21CHA N NE LC H1CH2S PE A KE R O U TP U TS+-+63H z1 25 HzC ON ST AN T DIRE CT IV IT YH OR N EQ/ AI R EQC ON ST AN T DIRE CT IV IT YH OR N EQ/ AI R EQINP U TT HR UT HR UINP U TA MP M O DEF RE QU EN CY4 .5kH zO N6 k Hz2 k HzM ON OB RI DG EL IM IT ER(C H1 & C H2 )O FFF UL L R AN GES UB W OO FERL OW C UTF ILT E RL OW C UTF IL TE RO UT P UT AP P LIC AT IONCAUTIONB ALAN CEDORU NB AL AN CE DB AL AN CE DORU NB ALAN CE DA IR E QM ON OB RIDG EO N/ B RI DG E/ M ON O1 70 H zO F F4.5 k Hz6 k Hz2 k HzA IR E Q1 20 VA C 50/60 H z 1500 WA TT S+-1 70 H z1 00 H zO FFS TA GEM ON IT OR1 00 H zS T A GEM ON IT ORO FFT YP IC ALO NO FFT YP IC ALT YPIC AL35 HzT YPIC AL35 Hz( MONO B RIDG E)1200 WAT T S4 OHM LOAD MI N.600 WA T TS C H2 O HM S LO AD M IN .S TE RE OT YP IC ALS T E RE OT YP IC ALA IR E QA IR E Q15462372534M1200/M1400 SERVICE MANUALSPECIFICATIONS6SPECIFICATIONSCONTINUOUS AVERAGE OUTPUTPOWER, BOTH CHANNELS DRIVEN:M1200225 watts per channel into 8 ohms from 20Hz to20kHz, with no more than 0.025% THD400 watts per channel into 4 ohms from 20Hz to20kHz, with no more than 0.050% THD600 watts per channel into 2 ohms from 20Hz to20kHz, with no more than 0.095% THDBridged mono operation:800 watts into 8 ohms from 20Hz to 20kHz, withno more than 0.050% THD1200 watts into 4 ohms from 20Hz to 20kHz, withno more than 0.095% THDMaximum Power at 1% THD:250 watts per channel into 8 ohms425 watts per channel into 4 ohms640 watts per channel into 2 ohms850 watts into 8 ohms bridged1280 watts into 4 ohms bridgedM1400 / M1400i250 watts per channel into 8 ohms from 20Hz to20kHz, with no more than 0.012% THD425 watts per channel into 4 ohms from 20Hz to20kHz, with no more than 0.025% THD630 watts per channel into 2 ohms from 20Hz to20kHz, with no more than 0.050% THDBridged mono operation:850 watts into 8 ohms from 20Hz to 20kHz, withno more than 0.025% THD1260 watts into 4 ohms from 20Hz to 20kHz, withno more than 0.050% THDMaximum Power at 1% THD:300 watts per channel into 8 ohms500 watts per channel into 4 ohms700 watts per channel into 2 ohms1000 watts into 8 ohms bridged1400 watts into 4 ohms bridgedNote: Power ratings are specified at120VAC (U.S. and Canada) and 240VAC(Export) line voltages.The M1200/M1400 power amplifiers drawlarge amounts of current from the AC line withcontinuous sine wave testing. Accuratemeasurement of power requires a steady andstable AC supply. This means the lineimpedance must be very low to insure that thepeak AC line voltage does not sag to less than97% of its value.If driving highly reactive loads, we recommendthat the limiter circuit be engaged.POWER BANDWIDTH:20Hz to 70kHz (+0, 3 dB)FREQUENCY RESPONSE:20Hz to 40kHz (+0, 1 dB)10Hz to 70kHz (+0, 3 dB)DISTORTION:THD, SMPTE IMD, TIM 0.025% 8 0.050% 4 107 dB below rated power into 4 ohmsCHANNEL SEPARATION: 80 dB 1kHzDAMPING FACTOR:350 minimumINPUT IMPEDANCE:20k ? balanced bridgingINPUT SENSITIVITY:1.23 volts (+4 dBu) for rated power into 4 ohmsGAIN:30.25 dB (32.5V/V)MAXIMUM INPUT LEVEL:9.75 volts (+22 dBu)VERSION 1.1SPECIFICATIONS7RISE TIME: 50V/s 100V/s bridgedCurrent Slew Rate 32A/s at 2CMRR: 40 dB, 20Hz to 20kHzLOAD ANGLE:8(jx) time independent at 84(jx) time dependent, T 6 min. at 42(1jx) time dependent, T 2 min. at 2TRANSIENT RECOVERY: 1s for 20 dB overdrive 1kHzHIGH FREQUENCY OVERLOAD ANDLATCHING:No latch up at any frequency or level.HIGH FREQUENCY STABILITY:Unconditionally stable driving any reactive orcapacitive load.TURN ON DELAY:3 secondsVARIABLE LOW-CUT FILTER:10Hz (Off) to 170Hz, 2nd Order BesselSUBWOOFER LOW-PASS FILTER:Switched: 63Hz/125Hz, 3rd Order BesselCONSTANT DIRECTIVITY HIGHFREQUENCY BOOST:2kHz to 6kHz (+3 dB points)6 dB/octave high-frequency shelving filter,(shelving occurs at approximately 30kHz)LIMITER SECTION:Complementary Positive and Negative PeakDetectingINDICATORS:6 meter LEDs per channelSIG (Signal Present), 20, 9, 6, 3, OL(Overload)CH 1 & 2PROTECT LEDsSHORT LEDsTEMP STATUSCOLD/HOT LEDsPOWER CONSUMPTION:65 watts at idle900 watts with musical program fully loaded(2 ohms per side, or 4 ohms bridged)550 watts with musical program fully loaded(4 ohms per side, or 8 ohms bridged)850 watts at full power into 8 ohms(continuous sine wave)1500 watts at full power into 4 ohms(continuous sine wave)2500 watts at full power into 2 ohms(continuous sine wave)AC LINE POWER:US120VAC, 60HzEurope240VAC, 50/60HzJapan100VAC, 50/60HzKorea220VAC, 60HzAC DROP-OUT VOLTAGE:At approximately 50% of rated line voltagePHYSICAL:Height3.5 inches (89mm)Width19.0 inches (483mm)Depth15.25 inches (387mm)Overall Depth16.25 inches (413mm)Handle Depth1.25 inches (32mm)Weight36 pounds (16.3kg)Since we are always striving to make our stuffbetter at Mackie Designs by incorporating newand improved materials, components, andmanufacturing methods, we reserve the right tochange these specifications at any timewithout notice.M1200/M1400 SERVICE MANUALCIRCUIT THEORY8CIRCUIT THEORYMuch of the circuitry in the M1200/M1400 is self explanatory from the schematic. Thissection will explain the unique circuits and architecture. Samples in this section will referto Channel 1 (Left) for circuitry that is identical on both channels.INPUT CIRCUITRYRefer to schematic on page 23.The signal path begins with the INPUT BOARD. Following Channel 1s input, signal is fedto a unity gain differential op-amp, U1A. The signal is next sent to U1B which serves asboth HPF and CD horn EQ. If not in SUBWOOFER mode, the summing amp (U2B) andLPFs (U3A, U3B) are bypassed. The signal is sent via J11 to the gain control on theDISPLAY BOARD. After the gain control, the signal is buffered by U7A, returned to theINPUT BOARD and routed to the MAIN BOARD via J16.Channel 2s input signal path is electrically identical to Channel 1s in STEREO mode. InPARALLEL MONO mode Channel 2s input signal is ignored and Channel 1s input is sentto Channel 2s gain control via SW5A. For BRIDGE MONO operation, Channel 1s inputsignal is inverted by U2A and routed to the MAIN BOARD via SW5C.POWER AMPLIFIER CIRCUITRYRefer to schematic on page 27.The M1200/M1400 use a class AB triple darlington output with complementary outputdevices. The main power supply is +/