Mackie_hr824_service_manual 电路图 维修原理图.pdf

HR824 High Resolution Active Studio Monitor SERVICE MANUAL 1999 MACKIE DESIGNS, INC. 820-183-00 ? 收音机爱好者资料库 Ra d i o Fa n s .CN Page 3 is interactive 2 CAUTION AVIS RISK OF ELECTRIC SHOCK DO NOT OPEN RISQUE DE CHOC ELECTRIQUE NE PAS OUVRIR CAUTION: TO R EDU CE THE RISK OF ELEC TRIC SHO CK D O NOT REMOVE THE C OVER (OR BAC K) NO USER SER VICEABLE PAR TS INSIDE REFER SER VICING TO QU ALIFIED PERSON N EL W ARNING: TO REDU CE THE R ISK OF FIRE OR ELECTRIC SHOCK, D O NOT EXPO SE THIS PROD UC T TO R AIN OR MO IS TU R E TO PREVENT ELECTRIC SH OCK, D O NOT U SE THIS POLARIZED PLU G W ITH AN EXTENSION C ORD , R ECEPTAC LE O R OTH ER O UTLET UNLESS TH E BLAD ES CAN BE FULLY INSER TED TO PREVENT BLADE EXPOSURE. ATTENTION: POUR EVITER LES RISQ UES DE C HOC ELECTRIQU E, NE PAS ENLEVER LE CO UVERC LE. AU CU N EN TR ETIEN DE PIECES INTERIEURES PAR L USAGER. C ON FIER L ENTRETIEN AU PER SONNEL QUALIFIE. AVIS:POUR EVITER LES RISQUES DINCENDIE O U DELECTROCUTIO N, NEXPOSEZ PAS CET ARTICLE A LA PLUIE O U A LHUMIDITE. POUR PREVENIR LES CH OC S ELECTRIQU ES N E PAS UTILISER CETTE FICHE POLARISEE AVEC UN PR OLONGATEUR , UN PRISE DE CO UR ANT OU UN E AUTRE SO RTIE D E COU RANT, SAUF SI LES LAMES PEUVENT ETRE INSEREES A FOND SANS LAISSER AUCUN E PARTIE A DECO UVERT. This apparatus does not exceed the Class A/Class B (whichever is applicable) lim its for radio noise em issions from digital apparatus as set out in the radio interference regulations of the Canadian Departm ent of Com m unications. ATTENTION :Le prsent appareil num rique nm et pas de bruits radiolectriques dpassant las lim ites applicables aux appareils num riques de class A/de class B (selon le cas) prescrites dans le rglem ent sur le brouillage radiolectrique dict par les m inistere des com m unications du Canada. This equipm ent has been tested and found to com ply with the lim its for a Class A digital device, pursuant to part 15 of the FCC rules. These lim its are designed to provide reasonable protection against harm ful interference when the equipm ent is operated in a com m ercial environm ent. This equipm ent generates, uses, and can radiate radio energy and, if not installed properly and used in accordance with the instruction m anual, m ay cause harm ful interference to radio com m unications. Operation of this equipm ent in a residential area is likely to cause harm ful interference in which case the user will be required to correct the interference at his own expense. The lightning flash with arrowhead symbol within an equilateral triangle is intended to alert the user to the presence of uninsulated dangerous 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. 收音机爱好者资料库 Ra d i o Fa n s .CN 3 CONTENTS SHIPPING .3 INTRODUCTION .4 TECHNICAL SUPPORT .4 DISCLAIMER.4 OVERVIEW.5 REAR PANEL .6 FRONT PANEL .7 SPECIFICATIONS .8 BLOCK DIAGRAM .9 WIRING DIAGRAM.10 PACKAGING PARTS.11 QUICK PARTS. 11-12 TEST PROCEDURES . 13-19 PARTS LIST . 21-25 IC AND TRANSISTOR CHARTS . 25-26 FOLD-OUT SECTIONS: SCHEMATICS.A1-A2 PRINTED CIRCUIT BOARDS REV A.A3-A4 PRINTED CIRCUIT BOARDS REV B .A5-A6 FINAL ASSEMBLY . A7-A13 SHIPPING When shipping this speaker, make sure that all the original packaging is used, including both the inner and outer boxes, and especially the thin, white sheet material. If shipped in just one box or without the sheet material, the lovely finish can be damaged. Shipping damage 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 inside the amplifier section. 收音机爱好者资料库 Ra d i o Fa n s .CN Click on any item to open that page 4 INTRODUCTION This manual contains service information for the HR824 Powered Studio Monitor. It is recommended that you also have a copy of the owners manual as this contains the complete operating instructions. To service the HR824, technicians should be familiar with op-amp based and discrete amplifier circuitry, speaker repair and speaker performance testing. Presentation of this manual does not constitute endorsement of qualifications by Mackie Designs. PROTECT YOUR HEARING The HR-824 speakers are capable of producing high sound pressure levels. We recommend the use of hearing protectors to prevent permanent hearing loss. SERVICE TECHNICAL ASSISTANCE Mackie Designs, Service Technical Assistance, is available 8AM - 5PM PST, Monday through Friday for Authorized Mackie Service Centers, at 1-800-258-6883. Feel free to call with any questions and speak with a carefully-calibrated technician. If one is not available, leave a detailed message and a qualified Mackoid will return your call asap. DISCLAIMER The information contained in this manual is proprietary to Mackie Designs, Inc. The entire manual is protected under copyright and may not be reproduced by any means without express written permission from Mackie Designs Inc. WARNING Service on the HR824 must only be undertaken by experienced service technicians. ! SMD! The HR824 makes extensive use of surface mount components. Service technicians should have the tools, experience and patience to perform surface mount rework. 5 THE AMPLIFIERS The Fast Recovery amplifier design uses low negative feedback, yet allows the amplifiers to maintain low distortion and stability even when driven into clipping. The low-frequency amplifier produces up to 150 watts continuous (350 watts peak) before clipping, while the high-frequency amplifier produces up to 100 watts continuous (210 watts peak). THE PASSIVE RADIATOR The HR824 is a bass reflex 6th-order system, rotating in geo-synchronous orbit. Rather than use ports, the vent takes the form of a passive radiator, a mass-loaded flat piston coupled to the air trapped within the enclosure. The passive radiator is located at the rear of the cabinet, behind the power amplifier assembly. One primary advantage over simple porting is that a passive radiator can reproduce low frequencies with lower distortion and at a higher sound pressure level (SPL). The unique passive radiator design uses a diaphragm made with a composite honeycomb material providing exceptional stiffness to the radiating surface. The elliptical shape of the passive radiator takes up nearly the entire surface area available on the rear of the enclosure, allowing the passive radiator to move more air than Congress. This moving air also helps cool the amplifier. HR824 OVERVIEW The HR824 Studio Monitors are two-way, bi-amplified active monitors with a rear- firing passive radiator. One amplifier drives the woofer and another drives the tweeter. The crossover point is designed so that the high and low frequency drivers are fed only the frequencies they can best reproduce. The amplifiers are designed with protection circuits to minimize the danger of speaker damage due to overdriving. The amplifiers gain and frequency responses are individually hand-trimmed by a host of infernal adjustment pots to compensate for typical manufacturing tolerances. The adjustments produce a smooth frequency response from 39Hz to 20kHz (1.5dB) with minimal phase difference. THE DRIVERS The monitors feature an 8.75-inch die-cast magnesium frame woofer and a 1-inch viscous edge-damped aluminum-alloy dome tweeter on the front, and a 6-inch x 12-inch elliptical flat piston passive radiator in the back. The high-frequency driver is mounted on a die-cast zinc exponential waveguide which results in wide, controlled dispersion of high-frequency sounds. The unique passive radiator design provides a smooth response down to 39Hz. THE CABINET The cabinet is made of high-density MDF wood from specially grown MDF trees. An internal “H” brace further increases the strength and rigidity (stiffness) of the box. An open-cell adiabatic pillow foam material gently fills the inside of the box to absorb internal reflections and dampen any standing waves. 6 LOW FREQ SWITCH The 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-frequency capability, use the 37Hz (NORMAL) position. You can use the 80Hz position to simulate a smaller loudspeaker. HIGH FREQ SWITCH The HIGH FREQ switch tailors the overall high-frequency response by 2dB at 10kHz. POWER MODE SWITCH In the OFF position, the power amplifiers are in Standby mode and produce no sound. Low-level circuitry is still active, but the power consumption of the circuitry is minimal (8 watts). In the ON position, the power amplifiers are live and operate normally. (The front panel ON/OFF switch must also be ON.) Since the power supply and low level circuitry are already active (assuming the speaker is plugged into a live outlet), this is an “instant on” function. In the AUTO ON position, the amplifiers turn on and off depending on the presence or absence of an input signal. An input signal level of 45dBu (minimum) activates the auto-on function. A silent period greater than five minutes activates the auto-off function. The red PWR LED on the front panel reflects the state of the amplifiers. Normally, use the front panel switch to turn the monitors on and off. If you unplug the power when a signal is still applied to the input, you may hear sound from the monitor. This is after about 6 seconds, when the muting circuit unmutes and the power supply finishes discharging. This is normal and not harmful to the monitor. MAINS INPUT Connect the power cord to this IEC socket, and plug the other end into your AC outlet. IMPORTANT: For safety reasons, the AC source must be a “3-prong” outlet with hot, neutral, and ground terminals. WARNING: Bypassing the plugs ground pin can be dangerous. Dont do it! REAR PANEL DESCRIPTION SIGNAL INPUTS The XLR female and TRS female connectors are connected in parallel . Both input connectors accept balanced or unbalanced signals. They are wired as follows (per the AES/IEC standard): XLRTRS Hot (+)Pin 2Tip Cold ()Pin 3Ring Shield (Ground)Pin 1Shield INPUT SENSITIVITY CONTROL The HR824 expects a line-level signal at its input connectors. The reference sensitivity is -7.5 dBu = 100 dB SPL at one meter (39 inches) with the INPUT SENSITIVITY control set to its NORMAL position. The HR824 is designed to operate with a +4 dBu signal when the INPUT SENSITIVITY control is in the NORMAL position. ACOUSTIC SPACE SWITCH This is a three-way switch that adjusts the low-frequency response of the speakers to compensate for their placement in the room. If you place the monitors against a wall (half space ), set the ACOUSTIC SPACE switch to the “B” position. This activates a shelving filter to reduce the low-frequency output by 2dB to compensate for the bass boost from half-space placement. If you place the monitors into the corners of your room (quarter space ), the low- frequency output approximately doubles from what it is in half space. Set the ACOUSTIC SPACE switch to the “A” position to reduce the low-frequency output by 4dB to compensate for the bass boost. If you use the HR824s free-standing, away from walls and corners (whole space ), set the ACOUSTIC SPACE switch to the “C” position (NORMAL). 7 and volume for the monitors. Change the LOW FREQ switch to 47Hz or 80Hz, if necessary, to reduce the bass response. This may allow the HR824s to play louder and eliminate most amplifier clipping. THERMAL PROTECTION The HR824 is designed to be efficient both electrically and thermally. If the heatsinks get too hot, a thermal switch activates, placing the HR824 into Standby mode (indicated when the red PWR LED turns off). Should this happen, make sure that airflow to the rear of the cabinet is not restricted. When the heatsinks cool down to a safe temperature, the switch resets and normal operation resumes. If your service customer complains that their HR824s keep thermalling out, make sure they keep them in the vertical position for improved ventilation. Also make sure the bias has been set correctly. FRONT PANEL DESCRIPTION ON/OFF SWITCH Use this switch to turn on or off the HR824 from the front. It works with the POWER MODE switch on the rear panel in the following way: If the rear POWER MODE switch is OFF, the front panel ON/OFF switch has no effect. The PWR LED remains off, so there. If the rear POWER MODE switch is ON, the front panel ON/OFF switch turns the HR824 on and off, as indicated by the PWR LED. If the rear POWER MODE switch in the AUTO ON position, the front panel ON/OFF switch turns the HR824 on and off as long as there is a signal present. OL (overload) LED This LED blinks when the amplifiers begin to clip, and lights steadily if the overload protection circuit has been triggered. Occasional blinking of the OL LED indicates that the loudest transients are reaching the maximum output capability of the amplifiers. Frequent