JBL 5233 User manual

ProfessionalSeries
TechnicalManual
ElectronicFrequency
DividingNetworks
5233SingleChannel
5234DualChannel
Thismanualcontainstechnicalinformation,
installationandoperatingprocedures
forqualifiedservicepersonnel.

Contents
TheJBL5233and5234
ElectronicFrequencyDividingNetworks1
Installation1
Operation5
Appendix6
ServiceNotes8
Note: Theinformationcontainedhereinandtheperform-
ancespecificationslistedabovealsoapplyto5231and
5232ElectronicFrequencyDividingNetworksidentified
byserialnumbershavingthesuffixA.
JBLcontinuallyengagesinresearchrelatedtoproductimprovement.
Newmaterials,productionmethodsanddesignrefinementsare
introducedintoexistingproductswithoutnoticeasa routineexpression
ofthatphilosophy.Forthisreason,anycurrentJBLproductmaydiffer
insomerespectfromitspublisheddescriptionbutwillalwaysequalor
exceedtheoriginaldesignspecificationsunlessotherwisestated.
Specifications
Gain0 dBinthepassband
RatedOutput6.2V (+18dBref,0.775V)
DistortionLessthan0,5%THD,20-20,000Hz
atratedoutput
Lessthan0.2%THD,20-20,000Hz
at+10dBref.0.775V
FrequencyResponse±0.5dB,20-20,000Hz
:CrossoverFrequencySelectablebyplug-inmodule,
3-dBcrossoverpoint± 10%
FilterSlope12dBperoctave
InputImpedanceGreaterthan50kfl
LoadImpedance600O orgreater
OutputImpedance47fl
ChannelIsolationGreaterthan60dB,20-20,000Hz
Signal/NoiseRatioGreaterthan90dB,20-20,000Hz
equivalentbandwidth
ControlsHighFrequencyLevel(eachchannel)
Power
SupplyVoltageSelect
PowerRequirement5 Watts,120/240V AC,50/60Hz
OperatingTemperatureUptoT32°F(55°C)
Dimensions1%x 19x7%indeep
44mmx483mmx194mmdeep
Mounting1 EIAstandardrackspace
PanelFinishSemi-glossnon-glarebakedenamel,
darkgray
NetWeight4 lb(1.8kg)eitherunitwith
accessorycrossovercard(s)installed.
ShippingWeight6.5lb:(3.0kg)eitherunit
WarrantyTwoyears
Accessories
CrossoverCards52-5120Blank
(onerequired52-5121250Hz
perchannel)52-5122500Hz
525123800Hz
52-51241200Hz
52-51255000Hz
5251277000Hz
52-5140Forthe4343StudioMonitor

TheJBL5233and5234
ElectronicFrequencyDividingNetworks
The5233and5234aredesignedforusewithstudiomonitor
orsoundreinforcementloudspeakersystemswherebi-ampli-
ficationortri-amplificationisdesirable.The5233(single
channel)and5234(dualchannel)featuredifferentialhigh
impedanceinputs,unitygaininthepassbandandunbalanced
lowimpedanceoutputs.The5233willprovidea singlechan-
nelcrossover.The5234providestwoseparatechannelswith
independentcrossoveraction(asina stereoinstallation).
Thepowerswitchandpilotlightfortheunitanda high
frequencylevelcontrolforeachchannelarelocatedonthe
frontpanelforeasyaccess.Thecrossoverfrequencyatwhich
eachchannelisoperatingisindicatedthrougha frontpanel
window.EithermodelcanbemountedinoneEIAstandard
rackspace.
Thedesiredcrossoverfrequencyisobtainedbyinserting
thecorrespondingprintedcircuitcardintoeachchannel's
circuitry.Crossovercardsareavailableformostcommonly
usedfrequencies.Filterslopesare12dBperoctavewith
highandlowfrequencyoutputattenuated3 dBatthecross-
overpoint.Cardsarealsoavailablewiththespecificcross-
overcharacteristicsrequiredfortheJBL4343bi-amplified
studiomonitor.Inaddition,blankcardscanbeobtainedfor
constructionofcrossovernetworksforotherfrequencies
(detailsprovidedintheappendix).
Advantages
1. Lower Distortion-The useofelectronicfrequencydividing
networksandmultipleamplifierspermitsdeliveryofoptimum
poweroverthedesiredaudiospectrumwithminimumdistor-
tion. Bydividingtheaudiospectrumpriortoamplification,the
individuallowfrequencyandhighfrequencyamplifierscan
performtheirfunctionswithgreatereffectiveness.
2. Flexibility— Insoundreinforcementapplicationsitisoften
desirabletocombineonelowfrequencydriverwithseveral
highfrequencyunitstoobtaina controlleddispersionpattern;
thus, onemayselectamplifiersoftheappropriatepowerfor
eachgroupoftransducers.
3. Cost Savings -Whenseveralloudspeakersystemsareto
beconnectedtoa singlechannel,significantcostsavingscan
berealizedsinceonlyoneelectronicfrequencydividingnet-
workneedbeused,therebyeliminatingthehighlevelpassive
crossovernetworksnormallyrequiredforeachofthe loud-
speakersystems.Moreover,sincenopowerisdissipatedin
resistiveattenuators,theamplifierrequirementsforhigh
powersoundsystemsmaybesubstantiallylessthanwhen
highleveldividingnetworksareused.
Installation
Theelectronicfrequencydividingnetworkreceivesthepro-
gramsignalfroma linelevelsource—preamplifier,studio
consoleorportablemixer-andseparatesthesignalintohigh
andlowfrequencybands.Outputsfromthenetworkfeed
theappropriatepoweramplifiers,whichinturndrivetheir
respectiveloudspeakersystemcomponents.Inputconnec-
tionsmaybebalancedorunbalanced,outputconnections
areunbalanced;shieldedcableisrequired.Ifoutputcable
lengthsaregreaterthan15to20feet(4.5m to6 m),isolation
transformers(600 n:600 n)arerecommendedateachout-
puttoreducethepossibilityofradiofrequencyinterferenceor
hum. Theoutputscandeliver+18dB(6.2V into600n)and
1

ConventionalPassiveNetworks
LOUDSPEAKER SYSTEM
r 1
PROGRAM
SOURCE
LOUDSPEAKER SYSTEM
PROGRAM
SOURCE
ONE
AMPLIFIER
PASSIVE
FREQUENCY
DIVIDING
NETWORK
Two-WaySystem
ONE
AMPLIFIER
PASSIVE
FREQUENCY
DIVIDING
NETWORKS
Three-WaySystem
ElectronicNetworks
LOUDSPEAKER SYSTEM
Two-WaySystemwithSingleChannelActiveCrossover
PROGRAM
SOURCE
THREE
AMPLIFIERS
Three-WaySystemwithDualChannelActiveCrossover
willdrivethelineinputsofconventionalamplifiers.Twoor
morepoweramplifierscanbedrivenfromeachoutput.
The5234dualchannelnetworkcanbeusedtotri-amplify
aloudspeakersystembyconnectingthelowfrequencyoutput
ofchannel2 totheinputofchannel1.(Twisttwounshielded
wirestogetheroruseshieldedcableforthisconnection.)The
channel1 outputscanthenbeusedtodrivethemidrangeand
lowfrequencyamplifiers.Typicalinstallationsarediagrammed
inFigure1.
PROGRAM
SOURCE
PROGRAM
SOURCE
LOUDSPEAKER SYSTEM
FOUR
AMPLIFIERS
ACTIVE
FREQUENCY
DIVIDING
NETWORK
LOUDSPEAKER SYSTEM
Figure1.Typical Installations Of The 5233 And 5234 Compared To
Conventional Passive Networks
Whenevera midrangeorhighfrequencydriverisconnected
directlytoa poweramplifier,a seriescapacitorisrecom-
mendedtoattenuateunwantedlowfrequency"on-off"
switchingtransientsignalswhichcandamagethedriver.
SpecificcapacitorvaluesaregiveninTable1.
HIGH
LOW
HIGH
MID
LOW
PROGRAM
SOURCE
TWO
AMPLIFIERS
ACTIVE
FREQUENCY
DIVIDING
NETWORK
HIGH
LOW
CHANNEL2
5234
CHANNEL1
HIGH
MID
LOW
LOUDSPEAKER SYSTEM
CHANNEL
2
5234
CHANNEL
1
HIGH
LOW
HIGH
LOW
TwoIndependentTwo-WaySystemswithDualChannelActiveCrossover

LOUDSPEAKER SYSTEM
PROGRAM
SOURCE
TWO
AMPLIFIERS
ACTIVE
FREQUENCY
DIVIDING
NETWORK
Itispossibletoconstructa systemusinganelectroniclow
frequencytransitionanda conventionalpassivenetworkfor
themidrangeorhighfrequencycrossover.TheJBL4350
StudioMonitor,diagrammedabove,issucha system.Ifa
pairof4350'saretobeused,a single5234canaccommo-
datebothsystems.Notethatthepassive,highlevelfrequency
dividingnetworksusedinallJBLstudiomonitorsdesigned
forbi-amplificationalreadyincorporatetherequiredatten-
uationcapacitorstoprotectthemidrangeandhighfrequency
drivers.
CrossoverCardInsertion
Priortoinstallingthe5233or5234,a crossovercardmust
beinsertedineachchannelasfollows:
1. Placethe5233or5234upsidedownona softsurface,
removethetwoPhillips-headscrewsfromeithersideofthe
caseandliftthebottomcoverfromthechassis.
2. Alignthethreeholesineachcrossovercardwiththecor-
respondingmountingpinsonthemainprintedcircuit
The crossover card is pressed on to mounting pins as shown. Note
the use of two hands to maintain proper alignment for installation or
removal of the card.
board. Thecomponentsonthecardshouldfacetoward
thechassiswiththefrequencydesignationlabeloriented
towardthefrontpanel.
3.Asthecardisgentlypressedagainstthemountingpin
stops[approximately % in,6 mm],electricalconnectionwill
bemadebetweenthecardconnectorandsixpinsonthe
printedcircuitboard.
4. Replacethebottomcoverandsecureitwiththefour
screws.Theunitisnowreadyformountingandconnec-
tionofthevariousinputsandoutputs.
Note: Operationofthe5233or5234withouta crossover
cardwillnotdamagetheunit.
Table1.MaximumValues
ForLowFrequency
AttenuationCapacitors
Crossover DriverImpedance
Frequency 4H8016n
250Hzto500Hz 150
,xF 80 juF 40^F
500Hzto5 kHz 80^F40^F20
5kHzandabove 8MF5/uF2 jiF
Capacitorworkingvoltagesshouldbeatleast50V.Donotuse
polarizedelectrolyticcapacitors;paperorMylarcapacitorsare
acceptable.A 50W resistorhavinga valueoftwotothreetimesthe
ratedimpedanceofthedrivershouldalsobeconnectedacrossthe
driverterminals.Thesecapacitorsareavailablefromelectronic
partssuppliers.A listingofcapacitorsthatmaybeobtainedfrom
JBLandtheformulafordeterminingcapacitorvaluesareprovided
inTable4,locatedintheappendix.Note:Belowthecutofffrequency
ofthecapacitor,thepoweramplifierwillbeunterminated.Ifthe
poweramplifierhasanoutputtransformer,a 20W resistorequalto
tentimesthedriverimpedanceshouldbeinstalledacrossthe
amplifieroutputterminals.
Mounting
The5233or5234canbemountedina singleEIAstandard
rackspacewithoutadditionalbracingorventilation.All
externalconnectionsaremadeontherearpanel.Mounting
hardwareissuppliedwitheachunit.
3
5233
PASSIVEFREQUENCY
DIVIDING NETWORK
ULTRA-HIGH
HIGH
MID
Figure2.Combining Electronic And Passive Frequency
Dividing Networks
Input and output terminals of the 5233 and 5234.

Connections
Shieldedcableisnecessaryforallinputandoutputconnec-
tions. Makecertainthattheshieldisproperlyconnected,as
showninFigures3 and4.
Input Connections—Inputs tothe5233and5234arefora
linelevelsource,balancedorunbalanced.Screwterminals
ontherearpanelareprovidedforconnectionofeachinput
andareclearlyidentified.Balancedconnectionsareshown
ingreen;exchanginghiandloconductorswillresultinphase
reversal.
Output Connections—Each outputchannelcandeliver6.2V
into600n orgreater(+18dBreferencedto 0.775 V).A sep-
aratepairofscrewterminals,locatedontherearpanel,is
providedforthelowandhighfrequencyoutputofeachchannel.
Outputswilldrivethelineinputofanyconventionalamplifier.
Typically,theimpedanceofa bridginginputisatleast5 kn
(usually10knormore);therefore,twoormorepowerampli-
fierscanbedrivenbya singleelectronicfrequencydividing
network.
J
DualChannel
5234ELECTRONICFREQUENCYDIVIDINGNETWORK
CHANNEL2 LO
5234
PROGRAM
SOURCE
PROGRAM
SOURCE
PROGRAM
SOURCE
Figure3.Wiring Diagram For Br Amplification.
AMPLIFIER
AMPLIFIER
AMPLIFIER
AMPLIFIER
LOUDSPEAKERSYSTEM
CHANNEL1
LOUDSPEAKERSYSTEM
CHANNEL2
4
SingleChannel
5233ELECTRONICFREQUENCYDIVIDINGNETWORK
PROGRAM
SOURCE
PROGRAM
SOURCE
AMPLIFIER
AMPLIFIER LOUDSPEAKERSYSTEM
HIGH
LOW
CHANNEL1
HIGH
LOW
HIGH
LOW

5234ELECTRONICFREQUENCYDIVIDINGNETWORK
Operation
VerificationOfSystemWiring
Itisimperativethateachoutputoftheelectronicfrequency
dividingnetworkbeproperlyconnected.Inadvertent
exchangeoflowandhighfrequencyoutputconnections—
atthenetwork,poweramplifiersortransducers—may
resultinseveredamagetomidrangeorhighfrequency
loudspeakersystemcomponents.
Thefollowingprocedureshouldbefollowedforeach
programchannelpriortooperation.
1. Withallpoweroff,settheHighFrequencyLevelcontrolat
"2" andadjusttheprogramsourceleveltominimum.(The
sourcematerialmaybewidebandnoiseormusic.)Ifthe
poweramplifiersareequippedwithlevelcontrols,adjust
themtoapproximatelyone-quarterpower.
2. Turnontheprogramsource,networkandamplifiersforthe
channelundertest.
3.Graduallyincreasetheprogramsourcevolumeleveluntil
audible.
Ifthesoundcomespredominatelyfromthemidrangeor
highfrequencydrivers,immediatelyshutpoweroffand
checkallwiring.
4. Ifthelowfrequencyloudspeakerproducesbass,gradually
advancetheHighFrequencyLevelcontrol.
Correctsystemwiringwillbeverifiedifthetreblecom-
ponentoftheprogrammaterialsimultaneouslyincreasesin
levelwhilecomingfromthemidrangeandhighfrequency
drivers.
TransducerPhasing
Oneimportantfactorcontributingtothenaturalsound
characterofa loudspeakersystemisthephaserelationshipof
thetransducersforanoctavebelowandaboveeachcross-
overfrequency.Twosuitablemethodsforestablishingproper
phaseofthecomponentsina two-wayloudspeakersystem
aredescribedinthefollowingparagraphs.Eitheronemaybe
used, dependingontheavailabilityoftestequipment.A three-
orfour-waysystemshouldbetreatedina similarmannerby
firstestablishingtheproperphaseforthetransducersofthe
lowfrequencytransitionandthenprogressingtothemid-
range,highfrequencyorultra-highfrequencytransducers,
asapplicable.
Objective Method-Arealtimethirdoctaveanalyzer, con-
densermicrophoneanda pinknoisesourcecanbeusedto
establishproperphaseoftheloudspeakersystemcom-
ponentsasfollows:
1. Usingpinknoiseasprogrammaterial,adjustsystem
volumeforcomfortablelisteningandsetthelevelsofthe
individualtransducerstodisplayflattestoverallfrequency
responseontherealtimeanalyzer.
2. Reversepolarityofthehighfrequencydriverandobserve
theeffectonfrequencyresponsethroughthecrossover
region
Properphasingofthetransducerswillhavebeenachieved
whentheflattestfrequencyresponsehasbeenobtained
throughthecrossoverregion,asshownontherealtime
analyzer.
5
5234
PROGRAMSOURCE
(UNBALANCED)
PROGRAMSOURCE
(BALANCED)
AMPLIFIER
AMPLIFIER
AMPLIFIER
LOUDSPEAKERSYSTEM
HIGH
MID
LOW
Figure4.Wiring Diagram For Tri-Amplification
Shieldedcableisnecessaryforallinputandoutputconnections,as
shown. Makecertainthattheshieldisproperlyconnectedtothe
groundterminal.

Subjective Method-tf testinstrumentationisnotavailable,
properresultscanbeobtainedbasedonprogrammaterial
asfollows:
1. Adjustvolumelevelforcomfortablelisteningandset
approximatesystembalanceusingpinknoiseorthenoise
heardbetweenstationsofanFMtuner.
2. Listentoa recordingofa malevoicelongenoughto
becomeaccustomedtotheperformanceofthe loud-
speakersystem.
3.Reversepolarityofthehighfrequencyloudspeaker,which
willproducea changeinvoicecharacter.
Whenthetransducersareproperlyphased,a recorded
malevoiceshouldsoundnaturalandexhibitpresence(oran
"upfront"quality],ascontrastedtoanundesirable"hollow"
soundthatcanbeheardwhentransducersareoutofphase.
Note:Ifthecrossoverfrequencyliesabove2 kHz,
reversingpolarityofthehighfrequencycomponentwill
createverylittle,ifany,perceptibledifferenceinsystem
performance.The"correct"polaritywillbethatwhich
yieldsthemostnaturalqualitywitha varietyofprogram
material.
Onceproperphaseamongthetransducersofa loud-
speakersystemhasbeendetermined,otherloudspeaker
systemsintheinstallation[assumingtheyarethesame)may
bephasedaccordingly.Ifdifferentloudspeakersystemsare
used, establishcommonphaseamongthelowfrequency
driversandfollowtheaboveproceduresforeachsystem.
LevelControlAdjustment
Inmostinstances,manufacturersofmulti-amplified loud-
speakersystemsprovideinstructionsforbalancinglevelsof
theindividualdriversofthesystem.Intheabsenceofformal
instructions,orinthecaseofcustomloudspeakersystems,
balancecanbeestablishedbyadjustinglevelstoachieve
flattestresponseona realtimeanalyzer,asdescribedinthe
transducerphasinginstructionsbeginningonthepreviouspage,
oronthebasisofsubjectiveevaluationoffamiliarprogram
material(or,moreaccurately,byusingpinknoiseorthenoise
betweenFMstations]asdescribedinthefollowingparagraphs.
Eachprogramchannelshouldbeadjustedindividually;
subjectiveevaluationshouldbemadewhileseatedinthe
normallisteninglocation.Ifsubjectiveanalysisistobeused,
andthepoweramplifiersareequippedwithlevelcontrols,
initiallyadjustthecontrolstoone-halfoftheirfullrotationand
thenregulateasnecessary.
Subjective Adjustment Of Bi-Amplified Systems-Jhe fol-
lowingappliestoa 5233ortoeachchannelofa 5234usedin
dualchannelbi-amplification
1. WiththeHighFrequencyLevelcontrolat"0"adjust
programsourcelevelforcomfortablelistening.
2. Rotatethenetworkcontrolclockwiseuntila satisfactory
highfrequencybalancehasbeenobtainedintheprogram
material. Ifnecessary,trimsourceoramplifierlevels.
Subjective Adjustment Of Tri-Amplified Systems—When
bothchannelsofa 5234areusedfora tri-amplified loud-
speakersystem,itisgenerallyinstalledsothattheChannel1
levelcontrolregulatestheoutputofthemidrangedriverand
theChannel2 levelcontrolgovernsthehighfrequencydriver,
controlgovernsonlythehighfrequencydriver.
1. WithbothHighFrequencyLevelcontrolsat"0','adjustthe
sourcelevelforcomfortablelistening.
2. RotatetheChannel1 levelcontrolclockwiseuntila satis-
factorymidrangelevelhasbeenobtainedintheprogram
material. Ifnecessary,adjustsourceoramplifierlevels
asappropriate.
3.IncreasetheChannel2 leveluntila satisfactoryhigh
frequencybalancehasbeenobtained.Itmaybenecessary
toreadjustmidrange,sourceoramplifierlevelstoachieve
themostdesirableoverallbalanceoftheloudspeaker
system.
Oncehighfrequencyandamplifieroutputlevelshavebeen
established,readjustmentisnotgenerallyneeded.Some
methodofmarkingorlockingthepoweramplifierlevel
controlsisrecommended.
Appendix
BlankCrossoverCardAssembly
Inadditiontothestandardcrossovercards,circuitsforother
crossoverfrequenciesmaybeassembledona blankcross-
overcard(JBLModel52-5120)usingstandardcomponents.
Filterslopes(12dBperoctave)areidenticalto thoseofthe
standardcrossovercards.Thecircuitsaredesignedtouse
fiveidenticalresistorsandfiveidenticalcapacitors.Thecross-
overfrequencycanbewrittenonthecardbracketandwill
appearthroughthefrontpanelwindowofthenetwork.
6

Figure5.Blank Crossover Card
Table2.
BlankCrossoverCard
ComponentValues
Resistorsareall%-Watt,5%tolerance.Capacitorsareall
5% tolerance,metalizedpolyester.
Crossover
Frequency
(Hertz)
Capacitors
C1'-C5'
(microfarads)
Resistors
R1'-R5'
(kilohms)
900 .012 10
1100 .010 10
1200 .0082 11
1500 .0082 9.1
2000 .0047 12
2500 .0018 24
5000 .0015 15
6000 .0012 16
7000 .0015 11
9500 .0012 10
1. Crossovercharacteristicsofthe51-5140aretailoredspecificallyforthe
4340StudioMonitor.
2. m'and R2'only.ThevalueforR3,'R4'andR5'is22kilohms,part
number10944.
Usingtwo 1 kn,y2W,10%resistorsona 52-5120blankcrossover
cardasshown,andinstallingthecard,willconverta crossover
channeltoa unitygainamplifierhavingoneinputandtwooutputs.
AudioDistributionAmplifier
Ablankcrossovercardcanbeusedtoconverta crossover
channeltoa unitygainaudiodistributionamplifierhaving
oneinputandtwooutputs.Twoofthesespeciallyloaded
cardswillconvertthe5234totwoindependentdirectam-
plifiers,eachhavingoneinputandtwooutputs,orthenet-
workinputscanbeparalleledtoprovidefouroutputsfrom
asinglesource.The"highfrequency"channelwillbeatunity
gainwhenthelevelcontrolisseta maximum.Thecontrol
canbeturneddowniflossisdesired.
Table4.
CapacitorsAvailableFromJBL
Thefollowing 10% tolerance,non-polarizedelectrolytic
capacitorsaresuitablefordriverprotectionandmaybe
orderedfroma JBL ProfessionalProductsdealerordirectly
from JBL.
JBL CrossoverFrequency
Part Value vs
Number (microfarads) DriverImpedance
4ohms 8ohms 16ohms
52938 72 1100Hz 550Hz 275Hz
52939 52 1500Hz 750Hz 400Hz
50341 20 4000Hz 2000Hz 1000Hz
10358 16.5 5000Hz 2500Hz 1200Hz
10359 13.5 6000Hz 3000Hz 1500Hz
10434 12 7000Hz 3500Hz 1700Hz
10391 8 10000Hz 5000Hz 2500Hz
10296 6 13000Hz 7000Hz 3500Hz
41040 4 20000Hz 10000Hz 5000Hz
11937 3 26000Hz13000Hz 7000Hz
Capacitorsizeforotherfrequenciescanbedeterminedusingthe
formulaC=
]b3
z°00
whereC iscapacitanceinmicrofarads,Z is
impedanceinohms,andF isone-halfthecrossoverfrequencyin
Hertz.
Figure6.Direct Amplifier Modification.
ComponentvaluesforthevariousfrequenciesarelistedinTable2.
Componentsshouldrestagainsttheprintedcircuitboard.Leads
shouldbesolderedandcutflush.
Thecomponentvaluesforothercrossoverfrequenciescanbe
calculatedusingtheformulaRC=whereR istheresistance
inkilohms,C iscapacitanceinmicrofarads,andF isfrequencyin
kilohertz.TherecommendedminimumvalueforR is4.7kilohms.
Table3.
JBLCrossoverCardComponentValues
Crossover Capacitors JBL Resistors JBL
ModelFrequency C1'-C5' Part R1'-R5' Part
Number (Hertz) (microfarads) Number (kilohms) Number
52-5121 250 .018 48481 24 35757
52-5122 500 .015 48480 15 35752
52-5123 800 .022 48482 6.2 35743
52-5124 1200 .0082 48947 11 35749
52-5125 5000 .0015 48927 15 35752
52-5127 7000 .0015 48927 11 35749
52-5140' .018 48481
27*
10255

ServiceNotes
The5233and5234utilizeintegratedcircuitry.Properopera-
tioncanbeverifiedbymeasurementofDCoutputvoltages
foreachintegratedcircuitwhichshouldmeasure0,±1/2V DC.
Ifthisspecificationisnotmet,theintegratedcircuitisdefec-
tiveandshouldbereplaced.
DCvoltagesaremeasuredwithrespecttoground.Itshould
benotedthata DCvoltmeterhavinga highinputimpedance
(10Mnorgreater]isrecommended.
Circuitlayouthasbeendesignedtofacilitateservicing.All
componentsareaccessibleandeasilyreplaced.Partsnot
normallyavailablethroughsupplyhousescanbeordered
froma JBLProfessionalProductsdealerorfrom:
JBL Customer Service
8500BalboaBoulevard
Northridge,California91329
POWER
8
Figure7. Power Input-5231 and 5232.
Powerswitchandpilotlightconfigurationsforthe5231and5232
differslightlyfromthe5233and5234.For220-Voperationremove
thejumpersbetweenterminals1 and2,andterminals3 and4 of
TB401, thenconnecta jumperbetweenterminals2 and3.