Mackie_srm450 电路图 维修原理图.pdf

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1、SRM450 Powered Speaker SERVICE MANUAL 1999,2000 MACKIE DESIGNS, INC. 820-184-00 收音机爱好者资料库 Ra d i o Fa n s .CN Page 3 is interactive Go To Bulletins 2 SERVICE ON THIS EQUIPMENT IS TO BE PERFORMED BY EXPERIENCED REPAIR TECHNICIANS ONLY 收音机爱好者资料库 Ra d i o Fa n s .CN 3 CONTENTS Introduction . 3 Block di

2、agram . 4 Specifications. 5 Overview . 6 Safety test . 8 Bias adjustment . 9 Test points. 10 Parts. A-1 Fold-out Sections Schematics and PCB layouts Main board . 227-1 INTRODUCTION This manual contains basic service information. It is essential that you have a copy of the users manual as this contai

3、ns the complete operating instructions. 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 te

4、chnician. 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 exp

5、ress written permission from Mackie Designs, Inc. SERVICE ON THIS EQUIPMENT IS TO BE PERFORMED BY EXPERIENCED REPAIR TECHNICIANS ONLY 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 Block Diagram INPUT THRU 1 J15 1 HI-PASS LOW CUTCONTOUR COMPRESSOR THRESHOLD COMPRESSOR SWEEPING F

6、ILTER LO-PASSDELAY 176uS HI-FREQ 40-120 Hz LO-FREQUENCY DRIVER TWEET LO-FREQ AMP HI-FREQ AMP SENSE RESISTOR BASS CONTROL SERVO LOOP WOOF PEAK LIGHT PEAK DETECTION THRESHOLD LPFTHRESHOLD + MID VDC + LO VDC + HI VDC TOROIDAL POWER TRANSFORMER FUSE POWER SWITCH ON OFF +15VDC SIGNAL SENSE SIGNAL SENSE M

7、UTE ON/OFF CONTROL MUTE MUTE POWER LEDS THERMAL LED THERMAL SWITCH LOW AC VOLTS SENSE TIMED TURNOFF SIGNAL LED 5 Specifications Low-Frequency Transducer Diameter300mm (12”) Voice Coil Diameter63.5mm (2.5”) Sensitivity (1W1m)98 dB Nominal Impedance8 ohms Power Handling300W Frequency Range50Hz 3000Hz

8、High-Freq Driver and Horn Diaphragm Diameter44.5mm (1.75”) Exit Throat Diameter24.5mm (1”) Diaphragm MaterialTitanium Sensitivity (1W1m)106 dB Nominal Impedance8 ohms Power Handling150W Frequency Range1000Hz 20,000Hz Low-Freq Power Amplifier Rated Power300 watts Rated THD 0.1% Cooling:Convection Ext

9、rusion Design:Class G, Parametric Servo Feedback High-Freq Power Amplifier Rated Power100 watts Rated THD 0.1% Cooling:Convection Extrusion Design:Conventional Class AB System specs Input TypeBalanced Differential Input ImpedanceLine: 20k ohms Input ProtectionRFI and level protected SensitivityLine:

10、 +4 dBu (centered) Mic: 36 dBu Maximum Input LevelLine: +22 dBu Low-Cut Frequency75Hz, Second-order filter EQPeaking +3 dB 55Hz, +3 dB 20kHz Over-Excursion Protection Second-Order High-Pass Filter Thermal ProtectionAmplifier shutdown, auto- reset Low-Line Voltage Shut Down: 60% Nominal line Acoustic

11、 Freq Response: 45Hz 20,000Hz Low-Freq 3 dB Point:55Hz Maximum SPL 1m:123 dB Low-Freq Crossover:24 dB/octave, time offset corrected High-Freq Crossover:24 dB/octave Crossover Frequency:1600Hz Driver ProtectionIndependent LF and HF compressors Low-Freq Roll-Off:Dynamic-signal level de- pendent Access

12、ory Interface15V DC Operating Temp Range10C - 45C (14F - 113F) Line Input Power US120V, 60Hz Europe230V, 50Hz Japan100V, 50/60Hz Disclaimer Since we are always striving to make our products better by incorporating new and improved materi- als, components, and manufacturing methods, we reserve the ri

13、ght to change these specifications at any time without notice. 1999 Mackie Designs Inc. All Rights Reserved. 6 Overview The SRM450 is an active two-way loudspeaker system capable of extremely high sound pressure levels. The Transducers The SRM450 active monitors feature a 12” high-power low-frequenc

14、y woofer and a 1.75” titanium diaphragm high-output precision compression driver. This high frequency driver is mounted on an acoustically non-resonant exponential waveguide, providing a wide, controlled dispersion and precise reproduction of the critical upper mid-range and high frequencies. The re

15、sult is an unbelievably smooth off-axis response that allows everyone in the audience to experience the same high-resolution audio no matter where they are seated. Each driver has been specifically designed by our engineers for optimum performance in the lightweight high-strength cabinet. FR Series

16、Power Amplifiers To power these beautiful things, each SRM450 includes two of our acclaimed FR Series “Fast Recovery” power amplifiers. Our exclusive design uses low negative feedback, yet allows the amplifiers to maintain low distortion and stability and to quickly recover when driven into clipping

17、. The amplifiers include the following features: The low-frequency amplifier produces up to 540 watts peak (300 continuous) before clipping. The high-frequency amplifier produces up to 150 watts peak (100 continuous) before clipping. Each amplifier has its own compressor circuit that acts when the i

18、nput signal is large enough to cause clipping, distortion and excessive voice coil heat. The compressor will automatically decrease the input signal to a safe level. The compressor in the low- frequency amp works independently from that in the high-frequency amp. The low-frequency amp uses a servo f

19、eedback loop which senses the current flowing in the woofer coil. This controls the low-frequency response and maintains low distortion at high output levels. The low-frequency amplifier also has a sweeping filter. This will automatically move the low cut-off frequency up or down depending on the am

20、plifier output. For example, if the amplifier is below clipping, the low-frequency cut-off point is 55Hz. As it approaches clipping, this shifts up smoothly to 120Hz, providing more power reserves and less distortion before clipping. This happens quickly and continuously, protecting the amplifer and

21、 the woofer and reducing any noticable distortion. Warning: Although the amplifiers have these protection circuits, you must still make sure the PEAK light is not blinking often or continuously. If it is, turn down your mixer faders, or preamplifier gain, or turn down the SRM450 LEVEL control. 7 The

22、 Crossover The built-in electronic crossover is a 24 dB/octave Linkwitz-Riley design. Although more expensive than other crossover designs, the benefits provided by the Linkwitz-Riley design have been well documented. These benefits include: Absolutely flat frequency response throughout the bandpass

23、, without the characteristic ripple near the crossover point exhibited by other designs. The sharp 24 dB per octave roll-off of the filters ensures that the transducers arent reproducing frequencies outside of their capabilities. The acoustic sum of the two driver responses is unity at the crossover

24、 frequency, resulting in perfect power response. Our heroic engineers have worked carefully to ensure that the SRM450 also provides perfect phase response. This diligence has yielded phenomenal accuracy, even if you are standing 20 feet away. The Cabinet The SRM450 cabinet was designed to be the str

25、ongest molded composite cabinet on the planet. This material is as strong as concrete, and rigid enough to prevent unwanted vibrations in the cabinet. It has built-in fly points for hanging, and a socket in the bottom for mounting on a tripod stand. Although it is an exceptional choice for installed

26、 sound situations, its light weight and durable finish also make it ideal for portable sound system use. The asymmetrical trapezoidal design of the cabinet makes it easy to use as a floor wedge for stage monitor applications. 8 You must perform the following leakage test before returning the unit to

27、 your customer. Take every safety precaution to protect yourself while doing this test. 1.Make a small loading RC circuit as shown in the diagram below, and connect the AC volt meter between the AC power source ground and any exposed metal on the unit under test. 2.Connect the unit under test to an

28、AC power source using a ground-lift adaptor, leaving the units safety ground floating. Turn the unit on. 3.The meter reading should be less than 750mVAC (note: this is equivalent to 0.5mA of leakage current). 4.Flip the plug over in the receptical so the hot and neutral are swapped. Verify that the

29、reading is still less then 750mVAC. 5.If either reading is greater than 750mVAC, then you must investigate and repair the unit before returning it to your customer. Safety test 9 Bias adjustment 1.Place the SRM450 on its side so that the heatsink fins are horizontal. 2.Connect the power cord and tur

30、n it on, with no input signal applied. Make sure that the TIMED TURNOFF switch is OFF. 3.Let it sit this way for an hour or more to allow the heatsink temperature to rise. You can play music through to speed things up. If you have a thermometer, the bias adjustment procedure is best done when the he

31、atsink temperature is 45 to 50 deg C. 4.Turn off the SRM450 and remove the power cord. 5.Remove the complete amplifier/heatsink assembly from the plastic speaker case but leave all wires connected, including the speaker wires. Support the amplifier so it can be safely turned on again. 6.Replace the

32、power cord and turn on the amplifier and take care not to touch any exposed live AC components. 7.No input signal is applied. 8.Low frequency amplifier bias adjustment: While the heatsink is still warm, measure the DC voltage across the 2 pins of J21. Adjust R202 until a reading of 4mV to 4.5mV is r

33、eached. See sheet 2 for the location of J21 and R202. Important: When finished adjusting, secure R202 with a small drop of paint, such as nail varnish. 9.High frequency amplifier bias adjustment: Measure the DC voltage across the 2 pins of J20. Adjust R212 until a reading of 4mV to 4.5mV is reached.

34、 Important: Secure R212 with a small drop of paint. 10. This completes the adjustment procedure. Reassemble and perform a full test. The Amplifier Bias of every SRM450 must be carefully adjusted as follows. 10 LOW FREQUENCY BIAS TEST POINT LOW FREQUENCY BIAS ADJUSTMENT POT HIGH FREQUENCY BIAS TEST P

35、OINT HIGH FREQUENCY BIAS ADJUSTMENT POT +80V +15 VDC -15 VDC -80V+45V-45V A-1 PART# DESCRIPTION PAGES 090-132-xxMaster Parts A-2 080-136-00Cabinet subassembly A-3 055-227-00Main Board A-4 SRM-450 PARTS LIST Parts Numbering guide 040-Cables 055- Finished PCB Assy 100- Pots and resistors 200-Capacitor

36、s 300- Semiconductors 400- Jacks/Connectors 500-Switches 510- Fuses 550- Chassis Metalwork 600-Transformers 601-Inductors 610- Wires and Cables 640- AC line cords 700-Hardware 760- Knobs/Plastic 770-Fans 790- Misc./Packing 800- Printed Material 860-EPROM Components noted with this symbol shall be re

37、placed only by the component specified. This is required to maintain product safety. Click on any item to open that page A-2 PART NO. DESCRIPTION REV QTYNOTES 090-132-00 SRM450 120V 9 A3 1 080-112-00 SA HTSK/XFMR/BD 12IN SPKR B1 A21 080-112-01 SA AMP SRM450 230V A2 A2 1 055-227-00-02 PCB ASSY SRM450

38、 AMPLIFIER 2C A2 1 See Page A-4 080-137-00 SA SW SRM450 B 1 080-138-00 SA XFMR 600-034-00 B A1 1 For 120V units 080-138-01 SA XFMR 600-034-01 A A1 1 For 230V units 080-138-02 SA XFMR 600-034-02 A A1 1 For 100V units 510-013-00 FUSE SB 7A 5X20MM 250V A 1 For 120V units 510-011-00 FUSE SB 4A 5X20 250V

39、 IEC B 1 For 230V units 510-024-00 FUSE SB 8A 5X20MM 250V A 1 For 100V units 550-398-00 SCRN BACK PNL MAIN SRM450 A 1 550-460-00 SHLD M6 PC SRM450 A 1 550-488-00 SHLD .015 M6X 4 3/4 ID 1 A1 1 551-071-00 PNT EXTR HTSK SRM450 A 1 700-010-04 TF 6-32X3/8 PHP BLKZC A 9 700-010-06 TF 6-32X1/2 PHP BLKZC A

40、4 700-011-00 MCH 4-40X1/4 BTNSKT BLKOX A 3 700-028-00 SEMS 6-32X1/4 PHP BLKZC B 8 700-034-02 SEMS 4-40X3/8 PHP BLKZC A 4 700-113-00 BOLT CAR 5/16-18 2IN STL A 1 701-016-00 5-20X5/16 PHPII TYP B BLK A 4 705-001-00 KEPNUT 6-32 A 2 705-005-00 NUT LOCK 4-40 A 4 705-018-00 NUT HEX 5/16-18 (GD-5) A 1 710-

41、005-00 WASHER INT STAR NO.6 BLK A 4 710-017-00 WASH SPLTLCK 5/16 HEAVY A 1 710-024-00 WASH FLAT 5/16 HARD (USS) A 1 720-007-00 TAPE DS 30MIL X 1.0W URTH A AR (as required) 730-001-00 THERMAL JOINT COMPOUND A AR 730-025-00 LOCTITE 222 A AR 740-001-00 TYRAP 3-1/4L A 1 740-003-00 TYRAP 8IN BLK A 3 760-

42、018-00 KNOB 11MM DARK GRAY B 1 780-052-00 INSULATOR PCB SRM450 A 1 780-111-00 WASH RUB (W/TRANSFORMER) A 1 080-136-00 SA SRM450 CABINET A 1 See next page (A-3) 092-903-00 LC IEC SJT 1250W 10A/125V A 1 640-002-02 LC JAPAN 12A 125VAC 8FT C 1 Linecord for 100V units 550-397-00 PLATE COVER SRM450 A 1 70

43、1-021-00 6X3/8 PHP PLASTITE BLK A 4 730-035-00 ACTIVATOR NO.2287 NORTON A AR 760-115-00 SIDE HANDLE GRIP SRM450 A 2 760-116-00 PLASTIC SIDE HANDLE A 2 800-139-00 SLEEVE SRM450 A 1 820-158-00 OWN MNL SRM450 A 1 Master Parts List 090-132-xx Components noted with this symbol shall be replaced only by t

44、he component specified. This is required to maintain product safety. 247b A-3 PART NO. DESCRIPTION REV QTYNOTES 055-280-00 PCB ASSY LED 1 080-156-00 SA CABLE PCB LED BLK/WHT 1 080-157-00 SA SUPPORT DRIVER THROAT 1 080-158-00 SA HARNESS BLU & BLU/BLK 1 080-159-00 WIRE YEL WOOFER 1 490-025-00 COMP DRI

45、VER 1 Comp driver 490-042-00 WOOFER SRM450 1 Woofer 490-047-00 SRM FRONT CASE MRB 1 Front case 490-048-00 SRM REAR CASE MRB 1 Rear case 490-052-00 POLE MNT KNOB 1 490-053-00 FOAM D BLK&WHT 1 550-408-00 TOP HANDLE PA SPKR 1 Top handle 550-410-00 GRILL 12IN SPKR ACTIVE B 1 Grill 700-123-00 SCREW SIDE

46、HDL GRIP MNTG 4 700-124-00 SCREW HDL MNTG TO CASE 4 700-125-00 SCREW WOOFER 8 701-021-00 6X3/8 PHP PLASTITE BLK A 4 701-026-00 SCREWS FOR CASE 17 701-027-00 SCREW BACK PANEL 12 701-028-00 SCREW FEET GRILL CD-THR 13 701-029-00 SCREW PCB ASSY LED 1 705-031-00 FLYING HW INS NUTS GALV 8 705-032-00 FLYIN

47、G HW INS NUTS BLK 2 710-049-00 WASH HDL MTNG TO CASE 4 710-050-00 WASH FLAT WOOFER 8 710-051-00 FLYING HW INS WASH GALV 8 710-052-00 FLYING HW INS WASH BLK 2 712-068-00 FLYING HW INSERTS 10 712-069-00 GROMMET LEAD WIRE 1 750-015-00 FEET 3 760-115-00 SIDE HANDLE GRIP SRM450 A 2 760-116-00 PLASTIC SIDE HANDLE A 2 780-135-00 GASKET WOOFER SRM450 1 Woofer Gasket 780-138-00 FOAM DA COMP DR TO CASE 1 780-139-00 FOAM D COMP D TO THROAT 1 780-140-00 GASKET FOR SPEAKER 1 79