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1、Technical Service ManualISA SeriesISA280ISA300TISA300TiISA450ISA500TISA500TiISA750ISA800TISA800TiISA1350*TD-000163-00*TD-000163-00Rev. AQSC Audio Products, Inc.Costa Mesa, CA 92626 USARoHSRadioFans.CN 收音机爱 好者资料库RadioFans.CN 收音机爱 好者资料库Technical Service Manual1ISA Series Power AmplifiersQSC Audio Prod

2、ucts, Inc.Technical Services GroupPhone:1-800 QSC AUDIO (1-800-772-2834) USA only+1 (714) 957-7150Fax:+1 (714) 754-6173Postal:1665 MacArthur Blvd.Costa Mesa, California 92626 USAE-mail:tech_Web:http:/ (product information and support)http:/ (parts and accessory sales)ISA280ISA450ISA750ISA1350ISA300T

3、 & ISA300TiISA500T & ISA500TiISA800T & ISA800TiISA SeriesTechnical Service ManualCopyright 2007 QSC Audio Products, Inc. All rights reserved.2QSC Audio Products, Inc.TD-000163-00 Rev. AISA amplifier, rear viewTechnical Service Manual3ISA Series Power AmplifiersTable of ContentsISA Series Performance

4、 Specifications .51. Introduction.71.1 Restriction of Hazardous Substances Directive (RoHS) .71.2 Service bulletins.71.3 The well-equipped service bench .71.4 Working with surface-mount components .8Two-terminal components (resistors, capacitors, diodes, etc.) . 8Three-terminal components (transisto

5、rs, etc.). 8Multi-pin components (ICs, etc.) . 91.5 Series description .10Outputs for distributed lines .101.6 Technical descriptions and theory of operation .10Power supplies .10Audio circuitry .10Clip detection .11DC protection .11Class H.12Bridged mono operation and protection.12Output transforme

6、rs and autoformers .121.7 ISA1350 circuitry .13Class H step drivers .13Bias circuitry .13Muting via the bias network .13DC fault protection .141.8 Revisions made during production.14ISA750 and ISA800T.142. Component identification and pinout .15NE5532AN Dual operational amplifier .15LM311 Voltage co

7、mparator .154N29 Opto-isolator.15LM13600 Dual operational transconductance amplifier .152N5064 Sensitive gate thyristor .15IRFZ44 TMOS power field effect transistor .162N3904 (NPN) and 2N3906 (PNP) Small-signal transistors .16MJE15032 (NPN) and MJE15033 (PNP) Driver transistors .16MAC224 Triac .162S

8、C5200 (PNP) and 2SA1943 (NPN) Power transistors .163. Troubleshooting: Symptoms, causes, & remedies .173.1 Excessive current draw.17Symptoms covered: .17Possible situations: .173.2 Protection, muting, and turn-on/turn-off delay problems.17Symptoms covered: .17Possible situations: .173.3 Faults with

9、signal present.18Symptoms covered: .18Possible situations: .183.4 Instability .19Symptoms covered: .19Possible situations: .193.5 Power supply & rail balancing problems .19Symptoms covered: .19Possible situations: .19Table 1: Bias and current limit adjustments .204. ISA calibration procedures .214.1

10、 Setting bias.21Tools and resources you will need: .21Procedure .214.2 Setting positive and negative current limits.214QSC Audio Products, Inc.TD-000163-00 Rev. ATools and resources you will need.21Procedure .215. Servicing ISA amplifiers .235.1 Mechanical disassembly and re-assembly .23Removing the

11、 channel modules .23Removing the AC board .236. Replacement parts .246.1 ISA280 parts and assemblies .24ISA280 Power Amplifier .24Chassis Assembly ISA280 (beginning June 2006) .24Chassis Assembly ISA280 (before June 2006) .25Main PCB Assembly ISA280 .26PCB Assembly, AC/Input ISA280, 300Ti, 300T, 450

12、, 500Ti, & 500T .286.2 ISA300T parts and assemblies.30ISA 300T Power Amplifier .30Chassis Assembly ISA300T .30Main PCB Assembly ISA300T .31PCB Assembly, AC/Input ISA280 300Ti, 300T, 450, 500Ti, & 500T .336.3 ISA300Ti parts and assemblies.34ISA300Ti Power Amplifier.34Chassis Assembly ISA300Ti (beginn

13、ing June 2006).34Chassis Assembly ISA300Ti (before June 2006) .35Main PCB Assembly ISA300Ti .36PCB Assembly, AC/Input ISA280, 300Ti, 300T, 450, 500Ti, & 500T .386.4 ISA450 parts and assemblies .39ISA450 Power Amplifier .39Chassis Assembly ISA450 (beginning June 2006) .39Chassis Assembly ISA450 (befo

14、re May 2006) .40Main PCB Assembly ISA450 .41PCB Assembly, AC/Input ISA280, 300Ti, 300T, 450, 500Ti, & 500T .436.5 ISA500T parts and assemblies.44ISA 500T Power Amplifier .44Chassis Assembly ISA 500T .44Main PCB Assembly ISA 500T .45PCB Assembly, AC/Input ISA280, 300Ti, 300T, 450, 500Ti, & 500T .476.

15、6 ISA500Ti parts and assemblies.48ISA500Ti Power Amplifier.48Chassis Assembly ISA500Ti.48Main PCB Assembly ISA500Ti .49PCB Assembly, AC/Input ISA280, 300Ti, 300T, 450, 500Ti, & 500T .516.7 ISA750 parts and assemblies .52ISA750 Power Amplifier .52Chassis Assembly ISA750 (beginning May 2006) .52Chassi

16、s Assembly ISA750 (before May 2006) .53Main PCB Assembly ISA750 .54PCB Assembly, AC/Input ISA750, 800Ti, & 800T .566.8 ISA800T parts and assemblies.58ISA800T Power Amplifier .58Chassis Assembly ISA800T .58Main PCB Assembly ISA800T .59PCB Assembly, AC/Input ISA750, 800Ti, & 800T .616.9 ISA800Ti parts

17、 and assemblies.62ISA800Ti Power Amplifier.62Chassis Assembly ISA800Ti.62Main PCB Assembly ISA800Ti .63PCB Assembly, AC/Input ISA750, 800Ti, & 800T .656.10 ISA1350 parts and assemblies .66ISA1350 Power Amplifier .66Chassis Assembly ISA1350 (beginning May 2006) .66Chassis Assembly ISA1350 (before May

18、 2006) .66Main PCB Assembly ISA450 .66PCB Assembly, AC/Input ISA.70Table of Contents continuedTechnical Service Manual5ISA Series Power AmplifiersISA Series Performance SpecificationsISA280 & ISA300TiISA450 & ISA500TiISA750 & ISA800TiISA1350OUTPUT POWER in wattsFTC: 20 Hz20 kHz 0.1% THD, both channe

19、ls driven, direct outputs8W per channel1852604508004W per channel2804006501300FTC: 50 Hz16 kHz 0.5% THD, both channels driven, transformer outputs70V or 100V (per channel)300 (ISA 300Ti)500 (ISA 500Ti)800 (ISA 800Ti)25V (per channel)240 (ISA 300Ti)400 (ISA 500Ti)640 (ISA 800Ti)FTC: 20 Hz20 kHz 0.5%

20、THD, both channels driven, direct outputs70V (per channel)1500EIA: 1 kHz 0.1% THD, both channels driven8 per channel2002805008504 per channel30045075014001 kHz 1% THD, typical, both channels driven2 per channel43070012002000Bridge Mono:8, 20 Hz20 kHz, 0.1% THD530800130026008, 1 kHz, 0.1% THD60090015

21、0028004, 1 kHz, 1% THD, typical830140024004000140V or 200V, 50 Hz16 kHz, 0.5% THD600 (ISA 300Ti)1000 (ISA 500Ti)1600 (ISA 800Ti)140V, 20 Hz20 kHz, 0.5% THD (direct outputs)300050V, 50 Hz16 kHz, 0.5% THD480 (ISA 300Ti)800 (ISA 500Ti)1280 (ISA 800Ti)DYNAMIC HEADROOM2 dB 42 dB 42 dB 42 dB 4DISTORTIONSM

22、PTE-IM 0.01% 0.01% 0.02% 300 8 300 8 300 8 250 8NOISE (unweighted 20 Hz to 20 kHz, below rated output)100 dB100 dB100 dB100 dBVOLTAGE GAIN31.6 (30 dB)40 (32 dB)50 (34 dB)64 (36 dB)INPUT SENSITIVITY, V RMSfull rated power 81.15v (+3.4 dBu)1.15v (+3.4 dBu)1.23v (+4.0 dBu)1.24v (+4.1 dBu)7. Schematics

23、and diagrams .717.1 ISA Series Chassis Assemblies .717.2 ISA280 (1st generation) Schematics.947.3 ISA280 (revised) Schematics.977.4 ISA300T Schematics.1007.5 ISA300Ti Schematics.1037.6 ISA450 (1st generation) Schematics.1067.7 ISA450 (revised) Schematics.1097.8 ISA500T Schematics.1127.9 ISA500Ti Sch

24、ematics.1157.10 ISA750 (1st generation) Schematics .1187.11 ISA750 (revised) Schematics .1217.12 ISA800T Schematics .1247.13 ISA800Ti Schematics .1277.14 ISA750, ISA800T, ISA800Ti Component locations.1307.15 ISA1350 Schematics.1327.16 ISA1350 Component locations .136Table of Contents continuedcontin

25、ued6QSC Audio Products, Inc.TD-000163-00 Rev. Al ac i pyT1l l uF2xaM3e l d IA5 . 08 A3A1 . 4A4 . 74 A5 . 4A6 . 6A5 . 112 A5 . 6*A5 . 9*A71l ac i pyT1l l uF2xaM3e l d IA5 . 08 A7 . 3A4 . 5A014 A6A6 . 9A612 A3 . 9*A7 . 41*A52l ac i pyT1l l uF2xaM3e l d IA6 . 08 A4A7 . 9A4 . 614 A3 . 6A6 . 51A722 A2 .

26、9*A32*A14Typical1Full2Max3Idle1.2 A8 6.4 A12.5 A25.5 A4 10 A20 A42 A2 14.5 A31 A*66 A*ISA Series Performance Specifications (continued)ISA 280 & ISA 300TiISA 450 & ISA 500TiISA 750 & ISA 800TiISA 1350INPUT IMPEDANCE10 k unbalanced20 k balancedCONTROLSFront: AC switch, Ch. 1 and Ch. 2 gainRear: 10-po

27、sition DIP switchINDICATORSPOWER:Green LEDCLIP:Red LED, 1 per channelSIGNAL:Yellow LED, 1 per channelCONNECTORSInput:Active balanced; XLR (pin 2 +) and detachable Euro-style terminal blocksOutput:Screw terminals with safety shroudDataPort V2:HD-15 femaleCOOLINGContinuously variable speed fan, back-t

28、o-front air flowAMPLIFIER PROTECTIONFull short circuit, open circuit, thermal, ultrasonic, and RF protectionStable into reactive or mismatched loadsLOAD PROTECTIONTurn-on/turn-off muting, AC coupling, triac crowbar (on each channel)OUTPUT CIRCUIT TYPEABABH (2-tier)H (3-tier)AB: Class AB+B complement

29、ary linear outputH: Class AB+B complementary linear output with Class H 2- or 3-tier high efficiency circuitDIMENSIONS19.0 (48.3 cm) wide, 5.25 (13.3 cm) tall (3 rack spaces)15.9 (40 cm) deep (rack mounting to rear support ears)WEIGHTShipping:ISA 280: 42 lb (19.1 kg)ISA 450: 46 lb (20.9 kg)ISA 750:

30、50.5 lb (23 kg)68 lb (30.8 kg)ISA 300Ti: 50 lb (22.7 kg)ISA 500Ti: 55 lb (25 kg)ISA 800Ti: 63 lb (28.6 kg)Net:ISA 280: 35 lb (15.9 kg)ISA 450: 40 lb (18.2 kg)ISA 750: 44.5 lb (20.2 kg)77 lb (34.4 kg)ISA 300Ti: 44 lb (20 kg)ISA 500Ti: 49 lb (22.3 kg)ISA 800Ti: 57 lb (26 kg)POWER REQUIREMENTSAvailable

31、 for 120 or 220240 VAC, 50/60 HzPOWER CONSUMPTION 120 VAC(both channels driven)Multiply currents by 0.5 for 230V unitsUS patents pendingSPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICETechnical Service Manual7ISA Series Power Amplifiers1. Introduction1.2 Service bulletinsContact QSC Technical Service

32、s to make sure you have the most up-to-date service bulletins for ISA Series amplifiers. Service bulletinsmay be distributed in hard copy, via fax, and electronically (Adobe Acrobat PDF) via CD-ROMs, FTP from the QSC web site(), and e-mail.One service bulletin has been issued for the ISA Series at t

33、he time this manual was printed: ISA0001, “ISA Turn-on Hangup” (ISA450,ISA500T, ISA750 and ISA800T)1.1 Restriction of Hazardous Substances Directive (RoHS)Beginning in June 2006 (serial number date code 0606xxxxx), all ISA Series amplifiers are manufactured to conform to the EuropeanUnions RoHS Dire

34、ctive, which reduces the amount of hazardous substances allowed in products for sale within its member nations. Inelectronic equipment such as audio power amplifiers, this applies primarily to certain toxic heavy metals, such as lead, which may bepresent in electronic components, solder, and other p

35、arts.RoHS-compliant materialsWhen servicing RoHS-compliant amplifiers, it is important for the service technician to use only RoHS-compliant components and solder(lead-free). All replacement parts provided by QSC for RoHS-compliant products are certified as RoHS compliant.RoHS-compliant toolsSolderi

36、ng irons and desoldering apparatus used on RoHS-compliant products must also not be contaminated by hazardous substances,such as lead. Therefore, you cannot use the same soldering and desoldering tools for RoHS-compliant products and solder as you do fornon-compliant products and solder. You must ei

37、ther use separate soldering irons, desoldering tools and braid, etc., or at the very leastdesignate separate tips and braids and use only the appropriate ones. If you contaminate a tip or braid, even inadvertently, by using it ona non-compliant product or solder, you can no longer use it with RoHS-c

38、ompliant products or solder.1.3 The well-equipped service benchTo properly service ISA amplifiers, a technician needs the right tools. The technicians service bench should have the following equipment: Digital multimeter with RMS AC voltage and current Digital clamp-on ammeter Dual-trace oscilloscop

39、e Audio distortion analyzer Non-inductive load resistors, configurable as 8 ohms (min. 500 watts capacity), as 4 ohms (min. 750 watts capacity), and 2 ohms (min.1200 watts capacity) Variable AC voltage source, such as a Variac or Powerstat variable transformer, with a rated current capacity of up to

40、 25A (for 120Vmodels) or 12A (for 230V models) Low-distortion audio sine wave generator Philips and flat screwdrivers Soldering iron with a fine tip (2560W recommended) Rosin-core solder (RoHS-compliant solder, or 60/40 or 63/37 for non-RoHS product only) Long-nose pliers Diagonal cutters Wire strip

41、persAutomated test equipment, such as an Audio Precision workstation, is very useful for servicing ISA amplifiers. Contact QSC TechnicalServices to obtain applicable AP test files.8QSC Audio Products, Inc.TD-000163-00 Rev. ASolder braidSolderSolderTweezersSolder1.4 Working with surface-mount compone

42、ntsISA amplifiers, like many modern electronic products, use surface-mount technology (SMT) components where appropriate in order tomake high-density circuitry that is reliable and economical to manufacture.SMT components in the ISA amps are used in the small-signal and control circuits, so they do

43、not handle significant amounts of power;therefore, they are subject to very little stress and should seldom fail. Sometimes they do fail, or they require replacement for aperformance upgrade or modification. Thus, it is important to know how to work with SMT components.Specialized tools and equipmen

44、t exist for soldering, unsoldering, and removing SMT components quickly and efficiently, but they are oftenexpensive. Most SMT repairs, though, can be handled reasonably well with common tools and equipment, such as tweezers, solder braid, andfine-tip soldering irons. The original factory components

45、 are tacked to the board with a spot of glue, so you might have to apply some forceto break the adhesive.Two-terminal components (resistors, capacitors, diodes, etc.)Removal1 Use two soldering irons, preferably about 25 to 40 watts, with fine tips.2 With a soldering iron in each hand, hold one tip o

46、n the solder at one end of the component and the othertip on the other end (Figure 1.1).3 Once the solder melts on both ends, grip the component between the two tips and lift it from the circuitboard.4 Use solder braid and a soldering iron to remove the solder from the two pads (Figure 1.2).Insertio

47、n1 With a soldering iron and appropriate solder, melt just enough solder onto one pad to create a smallmound (Figure 1.3).2 Grasp the component in the middle with tweezers. Melt the small mound of solder with the iron andplace the component across the two pads (in the correct orientation, if the com

48、ponent is sensitive todirection) and press it flat against the circuit board, with one end of the component immersed in themelted solder (Figure 1.4).3 Hold the component in place and take the soldering iron away. Let the solder harden to tack the component in place.4 Fully solder the other end of t

49、he component to its pad. Let the solder harden (Figure 1.5).5 Fully solder the tacked end of the component to its pad (Figure 1.6).Three-terminal components (transistors, etc.)Removal1 With a soldering iron and solder braid, remove as much solder as possible from the middle terminal ofthe component.

50、2 With a soldering iron in each hand, hold one tip on the solder at the terminal at one end of the compo-nent and the other tip on the terminal at the other end.3 When the solder on both ends melts, grip the component between the two tips and lift it from the circuitboard. You might need to quickly