Mackie-HR824-spk-sm 维修电路原理图.pdf
HR824High ResolutionActive Studio MonitorSERVICE MANUAL1999 MACKIE DESIGNS, INC.820-183-00?RadioFans.CN 收音机爱 好者资料库Page 3 is interactive2 CAUTION AVIS RISK OF ELECTRIC SHOCKDO NOT OPENRISQUE DE CHOC ELECTRIQUENE PAS OUVRIRCAUTION: TO R EDU CE THE RISK OFELEC TRIC SHO CK D O NOT REMOVETHE C OVER (OR BAC K)NO USER SER VICEABLE PAR TS INSIDEREFER SER VICING TO QU ALIFIEDPERSON N ELW ARNING: TO REDU CE THE R ISK OFFIRE OR ELECTRIC SHOCK, D O NOTEXPO SE THIS PROD UC T TO R AIN ORMO IS TU R ETO PREVENT ELECTRIC SH OCK, D ONOT U SE THIS POLARIZED PLU G W ITHAN EXTENSION C ORD , R ECEPTAC LE O ROTH ER O UTLET UNLESS TH E BLAD ESCAN BE FULLY INSER TED TO PREVENTBLADE EXPOSURE.ATTENTION: POUR EVITER LESRISQ UES DE C HOC ELECTRIQU E, NEPAS ENLEVER LE CO UVERC LE. AU CU NEN TR ETIEN DE PIECES INTERIEURESPAR L USAGER. C ON FIER L ENTRETIENAU PER SONNEL QUALIFIE.AVIS:POUR EVITER LES RISQUESDINCENDIE O U DELECTROCUTIO N,NEXPOSEZ PAS CET ARTICLE A LAPLUIE O U A LHUMIDITE.POUR PREVENIR LES CH OC SELECTRIQU ES N E PAS UTILISER CETTEFICHE POLARISEE AVEC UNPR OLONGATEUR , UN PRISE DECO UR ANT OU UN E AUTRE SO RTIE D ECOU RANT, SAUF SI LES LAMESPEUVENT ETRE INSEREES A FONDSANS LAISSER AUCUN E PARTIE ADECO UVERT.This apparatus does not exceed the Class A/Class B (whichever is applicable) lim its for radionoise em issions from digital apparatus as set out in the radio interference regulations of theCanadian Departm ent of Com m unications.ATTENTION :Le prsent appareil num rique nm et pas de bruits radiolectriques dpassantlas lim ites applicables aux appareils num riques de class A/de class B (selon le cas) prescritesdans le rglem ent sur le brouillage radiolectrique dict par les m inistere des com m unicationsdu Canada.This equipm ent has been tested and found to com ply with the lim its for a Class A digitaldevice, pursuant to part 15 of the FCC rules. These lim its are designed to provide reasonableprotection against harm ful interference when the equipm ent is operated in a com m ercialenvironm ent. This equipm ent generates, uses, and can radiate radio energy and, if notinstalled properly and used in accordance with the instruction m anual, m ay cause harm fulinterference to radio com m unications. Operation of this equipm ent in a residential area is likelyto cause harm ful interference in which case the user will be required to correct the interferenceat his own expense. The lightning flash with arrowhead symbol within an equilateral triangle is intended to alert the user to the presence of uninsulateddangerous voltage within the products enclosure, that may be of sufficient magnitude to constitute a risk of electric shock to persons. Le symbole clair avec point de flche lintrieur dun triangle quilatral est utilis pour alerter lutilisateur de la prsence lintrieur du coffret de voltage dangereux non isol dampleur suffisante pour constituer un risque dlctrocution. The exclamation point within an equilateral triangle is intended to alert the user of the presence of important operating and maintenance (servicing) instructions in the literature accompanying the appliance. Le point dexclamation lintrieur dun triangle quilatral est employ pour alerter les utilisateurs de la prsence dinstructions importantes pour le fonctionnement et lentretien (service) dans le livret dinstruction accompagnant lappareil.RadioFans.CN 收音机爱 好者资料库3CONTENTSSHIPPING .3INTRODUCTION .4TECHNICAL SUPPORT .4DISCLAIMER.4OVERVIEW.5REAR PANEL .6FRONT PANEL .7SPECIFICATIONS .8BLOCK DIAGRAM .9WIRING DIAGRAM.10PACKAGING PARTS.11QUICK PARTS. 11-12TEST PROCEDURES . 13-19PARTS LIST . 21-25IC AND TRANSISTOR CHARTS . 25-26FOLD-OUT SECTIONS:SCHEMATICS.A1-A2PRINTED CIRCUIT BOARDS REV A.A3-A4PRINTED CIRCUIT BOARDS REV B .A5-A6FINAL ASSEMBLY . A7-A13SHIPPINGWhen shipping this speaker, make sure that all the original packaging is used, includingboth the inner and outer boxes, and especially the thin, white sheet material. If shippedin just one box or without the sheet material, the lovely finish can be damaged. Shippingdamage due to improper packaging is not covered under Warranty!If you do not have the original packaging, it can be ordered from our parts department.Never use loose-fill foam pieces (peanuts) as these can damage the finish and get insidethe amplifier section.Click on any item to open that page4INTRODUCTIONThis manual contains service information for the HR824 Powered Studio Monitor. It isrecommended that you also have a copy of the owners manual as this contains thecomplete operating instructions.To service the HR824, technicians should be familiar with op-amp based and discreteamplifier circuitry, speaker repair and speaker performance testing. Presentation of thismanual does not constitute endorsement of qualifications by Mackie Designs.PROTECT YOUR HEARINGThe HR-824 speakers are capable of producing high sound pressure levels. Werecommend the use of hearing protectors to prevent permanent hearing loss.SERVICE TECHNICAL ASSISTANCEMackie Designs, Service Technical Assistance, is available 8AM - 5PM PST, Monday throughFriday for Authorized Mackie Service Centers, at 1-800-258-6883. Feel free to call with anyquestions and speak with a carefully-calibrated technician. If one is not available, leavea detailed message and a qualified Mackoid will return your call asap.DISCLAIMERThe information contained in this manual is proprietary to Mackie Designs, Inc. The entiremanual is protected under copyright and may not be reproduced by any means withoutexpress written permission from Mackie Designs Inc.WARNINGService on the HR824 must only beundertaken by experienced service technicians.! SMD!The HR824 makes extensive use ofsurface mount components.Service technicians should have thetools, experience and patience toperform surface mount rework.5THE AMPLIFIERSThe Fast Recovery amplifier design uses lownegative feedback, yet allows theamplifiers to maintain low distortion andstability even when driven into clipping.The low-frequency amplifier produces upto 150 watts continuous (350 watts peak)before clipping, while the high-frequencyamplifier produces up to 100 wattscontinuous (210 watts peak).THE PASSIVE RADIATORThe HR824 is a bass reflex 6th-order system,rotating in geo-synchronous orbit. Ratherthan use ports, the vent takes the form ofa passive radiator, a mass-loaded flatpiston coupled to the air trapped withinthe enclosure. The passive radiator islocated at the rear of the cabinet, behindthe power amplifier assembly.One primary advantage over simple portingis that a passive radiator can reproduce lowfrequencies with lower distortion and at ahigher sound pressure level (SPL).The unique passive radiator design uses adiaphragm made with a compositehoneycomb material providing exceptionalstiffness to the radiating surface.The elliptical shape of the passive radiatortakes up nearly the entire surface areaavailable on the rear of the enclosure,allowing the passive radiator to movemore air than Congress. This moving airalso helps cool the amplifier.HR824 OVERVIEWThe HR824 Studio Monitors are two-way,bi-amplified active monitors with a rear-firing passive radiator. One amplifier drivesthe woofer and another drives the tweeter.The crossover point is designed so that thehigh and low frequency drivers are fed onlythe frequencies they can best reproduce.The amplifiers are designed with protectioncircuits to minimize the danger of speakerdamage due to overdriving.The amplifiers gain and frequencyresponses are individually hand-trimmed bya host of infernal adjustment pots tocompensate for typical manufacturingtolerances.The adjustments produce a smoothfrequency response from 39Hz to 20kHz(1.5dB) with minimal phase difference.THE DRIVERSThe monitors feature an 8.75-inch die-castmagnesium frame woofer and a 1-inchviscous edge-damped aluminum-alloydome tweeter on the front, and a 6-inch x12-inch elliptical flat piston passive radiatorin the back.The high-frequency driver is mounted on adie-cast zinc exponential waveguidewhich results in wide, controlled dispersionof high-frequency sounds. The uniquepassive radiator design provides a smoothresponse down to 39Hz.THE CABINETThe cabinet is made of high-density MDFwood from specially grown MDF trees. Aninternal “H” brace further increases thestrength and rigidity (stiffness) of the box.An open-cell adiabatic pillow foammaterial gently fills the inside of the box toabsorb internal reflections and dampenany standing waves.6LOW FREQ SWITCHThe LOW FREQ switch inserts a steep low-frequency rolloff into the response curve.For most applications, use the 47Hz setting.If you want or need the extra low-frequencycapability, use the 37Hz (NORMAL) position.You can use the 80Hz position to simulatea smaller loudspeaker.HIGH FREQ SWITCHThe HIGH FREQ switch tailors the overallhigh-frequency response by 2dB at 10kHz.POWER MODE SWITCHIn the OFF position, the power amplifiersare in Standby mode and produce nosound. Low-level circuitry is still active, butthe power consumption of the circuitry isminimal (8 watts).In the ON position, the power amplifiersare live and operate normally. (The frontpanel ON/OFF switch must also be ON.)Since the power supply and low levelcircuitry are already active (assuming thespeaker is plugged into a live outlet), this isan “instant on” function.In the AUTO ON position, the amplifiers turnon and off depending on the presence orabsence of an input signal. An input signallevel of 45dBu (minimum) activates theauto-on function. A silent period greaterthan five minutes activates the auto-offfunction. The red PWR LED on the frontpanel reflects the state of the amplifiers.Normally, use the front panel switch to turnthe monitors on and off.If you unplug the power when a signal isstill applied to the input, you may hearsound from the monitor. This is after about6 seconds, when the muting circuitunmutes and the power supply finishesdischarging. This is normal and not harmfulto the monitor.MAINS INPUTConnect the power cord to this IECsocket, and plug the other end into yourAC outlet.IMPORTANT: For safety reasons, the ACsource must be a “3-prong” outletwith hot, neutral, and groundterminals.WARNING: Bypassing the plugs groundpin can be dangerous. Dont do it!REAR PANEL DESCRIPTIONSIGNAL INPUTSThe XLR female and TRS female connectorsare connected in parallel .Both input connectors accept balanced orunbalanced signals. They are wired asfollows (per the AES/IEC standard):XLRTRSHot (+)Pin 2TipCold ()Pin 3RingShield (Ground)Pin 1ShieldINPUT SENSITIVITY CONTROLThe HR824 expects a line-level signal at itsinput connectors.The reference sensitivity is -7.5 dBu = 100 dBSPL at one meter (39 inches) with the INPUTSENSITIVITY control set to its NORMALposition.The HR824 is designed to operate with a+4 dBu signal when the INPUT SENSITIVITYcontrol is in the NORMAL position.ACOUSTIC SPACE SWITCHThis is a three-way switch that adjusts thelow-frequency response of the speakers tocompensate for their placement in theroom.If you place the monitors against a wall(half space ), set the ACOUSTIC SPACEswitch to the “B” position. This activates ashelving filter to reduce the low-frequencyoutput by 2dB to compensate for the bassboost from half-space placement.If you place the monitors into the cornersof your room (quarter space ), the low-frequency output approximately doublesfrom what it is in half space. Set theACOUSTIC SPACE switch to the “A” positionto reduce the low-frequency output by 4dBto compensate for the bass boost.If you use the HR824s free-standing, awayfrom walls and corners (whole space ), setthe ACOUSTIC SPACE switch to the “C”position (NORMAL).7and volume for the monitors. Change theLOW FREQ switch to 47Hz or 80Hz, ifnecessary, to reduce the bass response. Thismay allow the HR824s to play louder andeliminate most amplifier clipping.THERMAL PROTECTIONThe HR824 is designed to be efficient bothelectrically and thermally.If the heatsinks get too hot, a thermalswitch activates, placing the HR824 intoStandby mode (indicated when the redPWR LED turns off).Should this happen, make sure that airflowto the rear of the cabinet is not restricted.When the heatsinks cool down to a safetemperature, the switch resets and normaloperation resumes.If your service customer complains thattheir HR824s keep thermalling out, makesure they keep them in the vertical positionfor improved ventilation. Also make surethe bias has been set correctly.FRONT PANEL DESCRIPTIONON/OFF SWITCHUse this switch to turn on or off the HR824from the front. It works with the POWERMODE switch on the rear panel in thefollowing way:If the rear POWER MODE switch is OFF, thefront panel ON/OFF switch has no effect.The PWR LED remains off, so there.If the rear POWER MODE switch is ON, thefront panel ON/OFF switch turns the HR824on and off, as indicated by the PWR LED.If the rear POWER MODE switch in the AUTOON position, the front panel ON/OFFswitch turns the HR824 on and off as longas there is a signal present.OL (overload) LEDThis LED blinks when the amplifiers begin toclip, and lights steadily if the overloadprotection circuit has been triggered.Occasional blinking of the OL LEDindicates that the loudest transients arereaching the maximum output capabilityof the amplifiers.Frequent or continuous blinking of the OLLED indicates that you have exceeded themaximum output capability of theamplifiers and that the amplifiers areclipping. If you persist, the overloadprotection circuit takes over, reducing theinput level. You should reduce the levelfrom your signal source until the OL LEDblinks occasionally or not at all.OVERLOAD PROTECTIONThe high and low frequency poweramplifiers have clipping detectors thatlight the OL LED when either poweramplifier output clips.If frequent clipping occurs, the driverthermal overload protection activates acompressor that reduces the input level tothe amplifiers. During this time the OL LEDlights continuously.The compressor was designed to protectthe speakers and its action is highlyaudible.When listening at a very high volume, youmay find that the OL LED lights frequently.Since the majority of the powerrequirements in any monitor are the lowfrequencies, selectively reducing the lowend can provide a little more headroom8SPECIFICATIONSAmplifier SectionLow-frequency amplifier:Rated power output: 150 watts, 4 loadBurst power output:350 wattsDistortion:THD: 0.035%SMPTE IMD: 0.035%DIM 100: 35V/sSignal-to-Noise Ratio: 102 dB, referenced to150 watts into a 4 loadHigh-frequency amplifier:Rated power output: 100 watts, 6 loadBurst power output:210 wattsDistortion:THD: 0.035%SMPTE IMD: 0.035%DIM 100: 35V/sSignal-to-Noise Ratio: 102 dB, referenced to100 watts into a 6 loadCrossover SectionCrossover Type:Modified Linkwitz-Riley, 24dB/octave 2kHzInput Impedance:20k, balanced bridgingCompressor:Independent high and low frequency overloaddetectionAcoustic Space Equalization:A position: 4 dB 100Hz, shelvingB position: 2 dB 100Hz, shelvingC position: flatLow Freq Filter:3 dB 35Hz3 dB 47Hz3 dB
