Klark Teknik dn330 User manual

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Operators & Service
Manual
DN330
EVI PRO AUDIO GROUP
KlarkTeknikBuilding,
WalterNashRoad,Kidderminster,
WorcestershireDY117HJ
England
Tel:[phone] Fax:[phone]

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DECLARATION OF CONFORMITY
TheDirectiveCoveredbythisDeclaration
89/336/EECElectromagneticCompatibilityDirective,amendedby92/31/EEC&93/68/EEC
EquipmentType ProductName
PresetEqualiser DN330
TheBasisonwhichConformityisbeingDeclared
TheproductsnamedabovecomplywiththerequirementsoftheaboveEUdirectivesbymeeting
thefollowingstandards:
EN 50081-1 (EN55022 class B)
EN 50082-1 (IEC801 Part 2, 4 / ENV 50140 / ENV 50141)
Signed: ........................... N. G. Tembe
Authority: HeadofEngineering
Date: 19thJanuary1996
Attention!
Theattentionofthespecifier,purchaser,installer,oruserisdrawntospeciallimitationstouse
whichmustbeobservedwhentheseproductsaretakenintoservicetomaintaincompliancewith
theabovedirectives.Detailsofthesespecialmeasuresandlimitationstouseareavailableupon
request,andarealsocontainedinproductmanuals.

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Attention!
Cables:
Thisproduct should onlybe used withhigh quality,screened twisted pairaudio cables, terminated
withmetal bodied 3-pinXLR connectors. Thecable should beconnected to pin1. Any othercable
typeorconfiguration fortheaudiosignalsmayresultindegradedperformanceduetoelectromagnetic
interference.
ElectricFields:
Should this product be used in an electromagnetic field that is amplitude modulated by an audio
frequencysignal(20Hz to 20KHz),thesignal to noise ratiomaybe degraded. Degradationofup to
60dB at a frequency corresponding to the modulation signal may be experienced under extreme
conditions(3V/m,90%modulation).

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CONTENTS
INTRODUCTION 8
THEDN330PRESETEQUALISER 9
INSTALLATION 11
INSTRUMENTFAMILIARISATION 13
AUDIO CONNECTIONS 14
SPECIFICATIONS 15
SERVICEINFORMATION 16
SCHEMATICS

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THANKYOU FORUSING THISKLARK TEKNIKPRODUCT
Toobtainmaximumperformancefromthisprecisionelectronicproduct,pleasestudytheseinstructions
carefully. Installingandoperatingtheequaliserisnotcomplicated,buttheflexibilityprovidedbyits
operatingfeaturesmeritsfamiliarisationwithitscontrolsandconnections. Thisunithasbeenprepared
tocomplywiththepowersupplyrequirementsthatexistinyourlocation.
Precautions
Beforeconnectingthisunittothemainspower,ensurethattheoperatingvoltageiscorrectforyourlocal
supply.
Donotinstallthisunitinalocationsubjectedtoexcessiveheat,dustormechanicalvibrations.
SafetyWarning
Thisunitisfittedwith3-pinpowersocket:Forsafetyreasonstheearthleadshouldnotbedisconnected.
Topreventshockorfirehazard,donotexposetheunittorainormoisture.
Toavoidelectricalshockdonotremovecovers. Referservicingtoqualifiedpersonnelonly.

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Afteryouhaveunpackedtheunit
Saveallthepackingmaterials-theywillprovevaluableshoulditbecomenecessarytotransportofship
thisproduct.
Pleaseinspectthisunitcarefullyforanysignsofdamageincurredduringtransportation. Ithasundergone
stringentqualitycontrolinspectionandtestspriortopackingandleftthefactoryinperfectoperatingand
mechanicalcondition.
If,however,theunitshowsasignofdamage,notifythetransportationcompanywithoutdelay. Only
you,theconsignee,mayinstituteaclaimagainstthecarrierfordamageduringtransportation.
Ifnecessary,contactyoursupplierorasalastresort,yourKlarkTeknikimportingagent,whowillfully
co-operateundersuchcircumstances.

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Introduction
Theequaliserisavitalcomponentinanyaudiosystem. Theentiresignalpassesthroughitandsoany
limitations imposed by the equaliser will compromise the performance of the whole system. For
example,anindifferentlydesignedequalisermayintroduceseverephasedistortion,noiseandother
anomoliesrelatedtocentre-frequencyaccuracy,filtershapeandattenuationaccuracywhichmay
manifestthemselvesasanoveralldeteriorationintheperceivedsoundqualityofthesystem. Clearlythis
inanunacceptablestateofaffairs,butfortunatelyyourchoicetoutiliseKlarkTeknikequaliserproduct
willeliminatetheseproblems,offeringyouunprecedentedproductperformancecoupledwiththe
highestfiltercalibrationandreliabilitystandardsintheindustry.
FormanyyearsKlarkTeknikhasbeenattheforefrontofequaliserdesign,andhavecarriedoutdetailed
researchintooptimumfilterresponsecharacteristics,includingtheirsonicperformance.
TheSeries300rangeofequalisersisadirectresultofthisresearch. Itshouldbenotedthatequalisation
cannotalwaysovercomeallfrequencyresponserelatedproblems. Thereareapplicationswherethe
abilitytocutorboosttheresponseataparticularfrequency,oroveracertainbandwidthotherthanthe
equaliserspecifiedone,isrequiredtoovercomeexceptionallydifficultresponseanomaliesornarrow
bandfeedbackproblems. Whensuchaninstanceisencountered,itmaybemoreappropriatetouse
the greater range of control provided by a parametric type equaliser, where the centre frequency,
bandwidthandamplitudeareallcontrollable.
When using an equaliser remember that the need to use large amounts of boost or cut within the
equalisationcurveindicatesthattheremaybesomethingfundamentallywrongwiththesoundsystem
orroomacoustics,whichshouldbefurtherinvestigatedandcorrectedbeforefinalequalisationis
applied.
Boththeinputandoutputcircuitryiselectronicallybalanced.Theinputisvoltageandcurrentmatched
andgivesexceptionalnoise,distortionandCMRperformance,whiletheoutputcircuitryisbasedon
theMidasXL3outputstagegivinghighdrivecapability.
Operationisnormallyfromthemainssupplywiththe24VDCsupplybeingutiliseduponthefailureof
themains.Ifno24Visavailablethentheinternalrelayswillbypasstheunitintheeventofpowerfailure.

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DN330Equaliser
TheKlarkTeknikDN330isasingle channel,30bandequaliseroffering12dBofcutorboostin
1/3octavestepsbetweenthefrequenciesof20Hzand20kHz.
FilterShapeandCombiningAction
Attheheartofanyequaliseristhebankoffiltersusedtoshapethesignalresponse,andKlarkTeknik
utiliseaproprietaryfiltercircuitwhichreplaceswhichreplacestheconventionalinductorbasedcircuit,
atthesametime,offeringseveralperformanceadvantages. Inductorbasedcircuitsareheavy,expensive
toproduceandsufferfromlowfrequencydistortionandinducedhum. KlarkTeknik’sproprietaryfilters
onthecontrarysuffernoneoftheseproblems,yetofferunequalledphaseresponseandcontrolaccuracy
withtheadditionalbenefitsoflownoiseandminimalripple.
Thenature,shapeandwayinwhichindividualequaliserfilterscombine,hasaprofoundeffectonthe
controlprovidedbytheequaliserandontheresultingqualityofsound. Themajorityofapplications
withinthesoundreinforcement,broadcast and recording fields, requireasmoothandcontinuous
equalisationresponsecurveinordertocorrectlycontourtheoverallresponsecharacteristicsofasound
system,loudspeaker,recordingeffectoraudiochannel. Toachievethis,theindividualfiltersmustbe
capableofcombiningsmoothlytogethertoresultinacontinuousresponsecurve,freefromshape
discontinuitiesinordertoavoidunwantedaudiblepeaksofanomaliesinthefinalsound.
Individualchannellevelcontrols,overloadindicatorsandbypassswitcheswithincorporatedlowcut
filtersarefeaturedonthecontrolpanel.
Otherfeatures
Thebypassswitchsilentlyremovesthegraphicequalisersectionsfromthesignalpath. Theequaliser
alsoincorporatesvariablelowandhighpass12dB/octavefilterswitharangefrom2K5Hzto30kHz
and 15Hzto300Hzrespectively.
OtherfeaturesincludeanoverloadLEDperchannel,whichwarnsofimpendingoverloadatanypoint
intheequaliser. Adetachablesecuritycoverisaninherentfeaturetopreventunauthorisedpersonnel
fromtamperingwiththecontrolsettings.
ThisproductisbuilttothesamehighelectricalandmechanicalstandardsasallKlarkTeknikequipment
andisbothrobustandstylish. Itoccupiesastandardoneunitofrackspace and has electronically
balancedinputsandoutputs.

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ReliabilityControl
Evenwiththeadvancedtechnologyincorporatedinthisproduct,eachinstrumentisgiventhefullbacking
ofKlarkTeknik’s“reliabilitycontrol”whichproveseachproductagainstaspecificationconsistentwith
thehighestprofessionalstandards. Onlytopqualitycomponentsareused,andeveryunitisbenchtested
andalignedbeforeaburn-inperiodandfinalperformancetest.

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INSTALLATION
TheDN330isdesignedforfixedinstallationswhereitisconventionallymountedintoastandard19”
equipmentrack.Theunitoccupiesonly1Uofheightandduetothelowoperatingpowerrequirements
ofthisunit,heatgenerationiskepttoaminimumallowingunitstobestackedaboveeachotherwithno
illeffects.Forcontinuedreliabilityitisnotrecommendedthattheequalisersarelocatedimmediately
aboveheatgeneratingunitssuchaspoweramplifiersormixerpowersupplies.Ifthisisunavoidablea
ventpanelbetweentheunitsisadvisable.
Precautions
Donotinstallthisunitinalocationsubjectedtoexcessiveheat,dustormechanicalvibration.before
connectingtheunittothemainssupply,ensurethattheoperatingvoltageiscorrectforyourlocalsupply.
Itisimportantthatyouobservethefollowingprecautions.
VoltageSelection&PowerConnection
ConnectiontothemainssupplyisbymeansofastandardIECpowersocket.Therearpanelvoltage
labelindicatesthevoltagerequiredforsatisfactoryoperationoftheunit.Tochangethemainsvoltage
pleaserefertothe‘VoltageChangeover‘sectiononpage12.
IMPORTANT Mainsvoltageadjustmentsshouldonlybecarriedoutbyaqualifiedservicetechnician.
TheDCsupplycanbeconnectedeitherbyseparate4mm(Banana)plugsorbyuseofthedualstacking
version.Correctpolaritymustbeobservedforoperation,thoughtheunitisprotectedagainstreverse
polarity.PleaserefertothesectionbelowregardingDCoperation.
NOTE:Asthereisnopoweron/offswitchonthisunit,assoonasthepower(MainsorDC)isconnected
theunitwillbeactive.
SafetyWarning
This unit is fitted with a 3-pin power socket. For safety reasons the earth lead MUST NOT be
disconnected.Aninternal‘floating’audiogroundreferenceisusedtoensurenoearthloopproblems
occurrelatedtotheinstallationofthisunit.Shouldanygroundloopproblemsbeencounteredtheywill
becausedbythecommoningofthegroundsoftheotherequipmentconnectedtotheequaliser.
TheDN330canbemadethecentralgroundreferenceasdetailedonpage12,thismodificationshould
onlybecarriedoutbyqualifiedservicetechnician.
Topreventshockorfirehazard,donotexposetheunittorainormoisture,onlyreplacefuseswiththe
correcttypeandrating.
Donotremovethecovers,referservicingtoqualifiedpersonnelonly.

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AudioConnections
TheinputsandoutputsarefullybalancedonXLRconnectorsandarewiredconventionallywithpin
1asground.Becausethesystemisfullyfloating,eitherpin2orpin3canbedesignatedashot
(phase)solongasthesameprotocolisadheredtoforbothinputsandoutputs.Tocomplywith
EMCregulationsfilteringisincorporatedintothisunit.Tomaximisethebenefitsofthisitisrecom-
mendedthattheXLRshellisnotconnectedtotheaudioground.
DCOperation
Thisunitisdesignedprimarilyforoperationfromthemainssupply.TheDCconnectionisintended
foruseasabackuppowerforevacuationandsimilarusesinconditionsofmainsfailure.Upon
failureofthemainssupply,astheunitisalreadyoperationaltheDCsupplyisonlyrequiredto
furnishthecurrentnecessarytomaintainoperation,nominally200mAat24V.
IfitisrequiredtopowertheunitonlyfromtheDCsupply,thisisquiteacceptablebutthepower
supplyMUSTbecapableofprovidinganinitial1.5Astartupcurrenttoinitiatetheswitchedmode
powersupply.Thedurationofthiscurrentdrawisonlyforapproximately5millisecondsafterwhich
thecurrentdropsto200mA.Thisisnoproblemwhenrunningfrombatteriesbutcouldoverloada
benchpowersupply.Pleaserefertotheapplicationnotelaterinthemanualforamethodofstarting
andrunningfromasupplythatonlygives250-300mA.

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FrontPanelFunctions
Otherthanthepoweronandclipindicatorsnousercontrolsorindicatorsareavailablewithallset-
upcontrolssecuredbehindthecentralremovablepanel.
Removethethreepozidrivescrewstogainaccesstothesecontrols.
1. Inputlevelcontrolallowingsystemgainofupto+12dBinthefullyclockwisepositionand
attenuationofupto-6dBinthefullyanticlockwiseposition.Whenthe‘slot’ishorizontalitis
inthe0dB, unitygainposition.
2. EQin/outswitch.Thisswitchallowsthebypassingoftheequaliserselectedasfollows:
Down: Equaliser&filtersbypassed. Thegaincontrolisstillactive.
Up: Equaliserincircuit.
3. Thelowfrequencyfilter(highpass)hasacontinuouslyvariableturnoverfrequencyfrom
15Hzto300Hz.
4. Thehighfrequencyfilter(lopass)hasacontinuouslyvariableturnoverfrequencyfrom2.5khz
to 30KHz.
5. Thirtyhighquality,sealedrotarypresetfilterlevelcontrolseachprovidingbetween+12dB
boostand-12dBcutatthe1/3OctaveISOstandardfrequencies. Whenthe"slot"ishori
zontalthefilterisflat.
6. Overloadled.Thesignallevelismonitoredatseveralseparatepointswithinthecircuitryof
theunit.Ifanyoneofthesesignalsexceedsathresholdset3dBbelowclippingtheledwill
light.Itmustberememberedthatexcessiveboostatsomefrequenciescombinedwithahigh
averageinputsignalcanoccasionallycausetheclipsensingthresholdtobeexceeded.Inthis
eventthegaincontrolshouldbeturneddowntocorrecttheproblem. However,iftheinput
signalitselfexceeded20dBtheinputstagewillbeoverloaded.Ifthisproblemarisesthenthe
signallevelfromtheequipmentfeedingtheequalisermustbereduced.

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RearPanelFunctions
7. MainsissuppliedviaanIECstandard3pinconnector.Acompatiblepowercordissupplied
withtheunit.
8. Themainsfuseislocatedinthedrawthatispartofthemainsinputconnector.Asparefuseis
alsostoredhere.Disconnecttheunitfromthemainssupplybeforereplacingthefuse.Always
replacethefusewiththecorrecttypeandrating.
9. Twosocketsareprovidedfortheconnectionofthe24VDCsupply.These are standard
4mm‘banana’type.Thesocketsareonastandard19mmpitchtoallowtheuseoftwinstackable
connectors.ThepolarityoftheDCsupplymustbemaintainedforoperationthoughincorrect
connectionwillnotdamagetheunit.
10. InputandoutputconnectionsareviacomplementaryXLRstyleconnectors.Forwiring
detailsseethepageentitledAudioConnections.
NOTE: ThesecuritycoverisnormallyfixedwithM3pozidrivescrews.Forinstallationswhere
theutmostsecurityisrequiredthesecanbe replacedwithtamperprooftypeofM3x6mm.
AudioConnections
Inputs
Theinputcircuitryisatransformerless,electronicallybalanceddesignwhichachievesasymmetryof
betterthan-50dBfrom20Hzto10kHz.
Itisalwayspreferabletodrivetheequaliserfromabalancedsource.Ifonlyanunbalancedsource
isavailableitisrecommendedthatitisconnectedasshownbelow.Connectthescreenonlyatthe
equaliserend.

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Outputs
Thestandardoutputsareelectronicallybalancedandiscapableofdriving
+19dBuinto600 ohmsand+20dBuinto2K.
Itisrecommendedthattheequaliserfeedsintoabalancedinput,howevertofeedanunbalanced
inputitisnecessarytoconnecttheantiphaseoutputtoground.ThisisbestcarriedoutontheXLR
outputconnectoroftheequaliser.
Note:Whenusingafullybalancedsystem,eitherpin2orpin3canbephase.

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TechnicalSpecifications
Input One
Type Electronicallybalanced
Impedance
Balanced 20Kohms
Unbalanced 10Kohms
Maxinputlevel 20dBm
Output One
Type Electronicallybalanced
Sourceimpedance 50ohms
Min.loadimpedance 600ohms
Max.level 20dBuwith2Kohmload
Performance
Frequencyresponse
20Hzto20kHz,EQflat +/-0.5dB
THD+N @ +4dB <0.01% @ 1kHz
Equivalentinputnoise
(20Hzto20kHzunweighted) <-86dBu
Gain -6 to +12dB
Filters
Type Proprietary“combining”
ISOcentrefrequencies 30, 25Hz to 20kHz
Frequencytolerance 5%
Maximumboost/cut +/-12dB
Highpassfilter 15Hzto300Hz,12dB/octave
Lowpassfilter 2K5Hzto30KHz,12dB/octave
Powerrequirements
ACVoltage 115/230 +/-12%, 50/60Hz
Consumption <15VA
DCVoltage 24V +/-12%
DCConsumption <250mA
Weight
Nett 2.5kg
Shipping 4kg
Dimensions
Width 482mm(19inches)
Height 45mm(13/4inches)
Depth 210mm(81/4inches)
Terminations
Inputs 3pinXLR
Outputs 3pinXLR
AC power 3pinIEC
DC power 2x4mm“Banana”type

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THEFOLLOWINGINFORMATIONISFORTHEUSEOF QUALIFIEDSERVICE
PERSONNELONLY
Donotattemptanyofthefollowingadjustmentsyourself
Thefollowingadjustmentsrequiretheremovalofthecover.Proceedasfollows:-
1. DisconnecttheunitfromthemainsandDCsupply.
2. Removetheeightpozidrivecoverscrews,3onthetop,2oneachsideand1 ontherear.
Keepthesesafeforreuselater.Liftoffthecover.
VoltageChangeover
Theunitisnormallyshippedpresettothemainssupplyvoltagerequiredforthecountry.Thisisindicated
ontherearpanel.
Toselectthealternativevoltageitisonlynecessarytoslidethevoltageselectorswitch,locatedtothe
rightofthemainstransformer,totheotherposition.
Pleaseensurethattherearpanelvoltagelabelisremovedandreplacedwithonestatingthenewvoltage
setting.
MakingtheDN330thesystemgroundreference
Undercertainunusualoperatingenvironmentsitmaybenecessarytousetheequaliserasthemain
groundreferenceandtieothersignalgroundstoit.Thisiseasilyaccomplishedasfollows:-
1. RemovetheM3pozidrivescrewlocatedinthecentreoftheboardlabelled‘ST3.’&
‘GroundLink’.
2. Fitasoldertagontothescrewandrefitensuringthetagislocatedoverthebarepcbsection
totheleftofthescrew.
3. Solderthetagtothecircuitboard.
4. Replacethecoverafteradjustment.

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KLARK TEKNIK Application Note 1
A Method of Starting & Powering the
DN320 & DN330 from a 24V Bench Supply.
CAUTION. Thefollowingisgivenasguidanceonlyandshouldonlybecarriedoutbysuitably
qualifiedandexperiencedpersonnel.
Theinformationisgiveningoodfaithandisnotintendedasadefinitivemethodof
achievingthedesiredresults.
Problem: “Ionlyhavea250-300mA24Vpowersupply.HowcanIruntheDN330fromit?”
Answer: 1. WiththesupplyOFF,connectacapacitorofapproximately10000mfdanda
workingvoltageofatleast25Vacrossthe outputterminals.
2. ConnectthepowersupplytotheDN330viaasuitableswitch, leaveintheopen
position.
3. Turnonthepowersupplyandallowacoupleofsecondsforthecapacitortocharge.
4. ClosetheswitchandtheDN330willpowerup.
Itdoesthisbecausethecapacitorprovidessufficientenergytoprovidetheswitchmodesupply’sstart
upcurrent.Oncethesupplyisrunningonlythenominal200mAoperatingcurrentisrequired.