McIntosh C34V User manual

IMPORTANTSAFETYINSTRUCTIONS
THESEINSTRUCTIONSARETO
PROTECTYOUANDTHEMCINTOSH
INSTRUMENT.BESURETO
FAMILIARIZEYOURSELFWITHTHEM.
1.Readallinstructions- Readthesafetyand
operatinginstructionsbeforeoperatingthe
instrument.
2.RetainInstructions- Retainthesafetyand
operatinginstructionsforfuturereference.
3.Heedwarnings- Adheretowarningsand
operatinginstructions.
4.FollowInstructions- Followalloperatinganduse
instructions.
WARNING:TOREDUCERISKOFFIREOR
ELECTRICALSHOCK,DONOTEXPOSETHIS
INSTRUMENTTORAINORMOISTURE.
5.PowerSources- Connectthepowersupplyonlyto
thetypedescribedintheoperatinginstructionsor
asmarkedontheunit.
6.Power-CordProtection- Routepower-supplycords
sothattheyarenotlikelytobewalkedonor
pinchedbyitemsplaceduponoragainstthem,
payingparticularattentiontocordsatplugs,
conveniencereceptacles,andthepointwherethey
exitfromtheinstrument.
7.Ventilation- Locatetheinstrumentforproper
ventilation.Forexample,theinstrumentshould
notbeplacedona bed,sofa,rug,orsimilar
surfacethatmayblockventilationopenings;or,
placed ina built-ininstallation,suchasa bookcase
orcabinet,thatmayimpedetheflowofair
throughtheventilationopenings.
8.Heat- Locatetheinstrumentawayfromheat
sourcessuchasradiators,heatregisters,stoves,or
otherappliance(includingamplifiers)thatproduce
heat.
9.WallorCabinetMounting- Mounttheinstrument
ina wallorcabinetonlyasdescribedinthe
ownersmanual.
10.WaterandMoisture- Donotusetheinstrument
nearwater- forexample,neara bathtub,
washbowl,kitchensink,laundrytub,ina wet
basement,orneara swimmingpool,etc.
11.Cleaning- Cleantheinstrumentbydustingwitha
drycloth.Cleanthepanelwitha clothmoistened
witha windowcleaner.
12.ObjectandLiquidEntry- Donotpermitobjectsto
fallandliquidstospillintotheinstrumentthrough
enclosureopenings.
TOEXTERNALANTENNA
TERMINALSOFPRODUCT
POWERSERVICE
GROUNDINGELECTRODESYSTEM
(reg.internalmetalwaterpipe)
OPTIONALANTENNA
GROUNDINGELECTRODE
DRIVEN8 FEET(2.44m)
INTOTHEEARTHIF
REQUIREDBY
LOCALCODESSEE
NECSECTION810-11
13.PowerLines- Locateanyoutdoorantennaaway
frompowerlines.
14.OutdoorAntennaGrounding- Ifanoutdoor
antennaisconnectedtotheantennaterminal,be
suretheantennasystemisgroundedtoprovide
someprotectionagainstvoltagesurgesandbuilt
upstaticcharge.
IntheU.S.A.,section810oftheNationalElectrical
Code,ANSl/NFPANo.70-1987,provides
informationonthepropergroundforthemast
andsupportingstructure,groundforthelead-in
wiretoanantennadischargeunit,andsizeof
groundconductors,locationofantenna-discharge
unit,connectiontogroundingelectrodes,and
requirementsforthegroundingelectrode.
Forgroundwire:
a)UseNo.10AWG(5.3mm2)copperNo.8 AWG
(8.4mm2)aluminum,No.17AWG(1.0mm2)
copper-cladsteel,bronzewire,orlargerasground
wire.
b)Secureantennalead-inandgroundwiresto
housewithstand-offinsulatorsspacedfrom4 feet
(1.22meters)to6 feet(1.83meters)apart.
c)Mountantennadischargeunitascloselyas
possibletowherelead-inentershouse.
d)UsejumperwirenotsmallerthanNo.6 AWG
(13.3mm2)copperorequivalentwhenseparate
antennagroundingelectrodeisused.
STAND-OFF
INSULATORS
ANTENNA
LEADINWIRE
BONDING
JUMPER
SERVICEENTRANCE
EQUIPMENT

15.NonusePeriods- Unplugthepowercordfromthe
ACpoweroutletwhenleftunusedfora long
periodoftime.
16.DamageRequiringService- Servicemustbe
performedbyqualifiedservicepersonnelwhen:
A.Thepowersupplycordortheplughasbeen
damaged;or
B.Objectshavefallen,orliquidhasbeenspilled
intotheinstrument;or
C.Theinstrumenthasbeenexposedtorain;or
D.Theinstrumentdoesnotappeartooperate
normallyorexhibitsa markedchangein
performance;or
E.Theinstrumenthasbeendropped,orthe
enclosuredamaged.
17.Servicing- Donotattempttoservicebeyondthat
describedintheoperatinginstructions.Allother
serviceshouldbereferredtoqualifiedservice
personnel.
18.Groundingor Polarization- Do notdefeatthe
inherentdesignfeaturesofthepolarizedplug.
Non-polarizedlinecordadaptorswilldefeatthe
safetyprovidedbythepolarizedACplug.
19.CAUTION:TOPREVENTELECTICALSHOCKDO
NOTUSETHIS(POLARIZED)PLUGWITHAN
EXTENSIONCORD,RECEPTACLEOROTHER
OUTLETUNLESSTHEBLADESCANBEFULLY
INSERTEDTOPREVENTBLADEEXPOSURE.
NotetoCATVsysteminstaller:
ThisreminderisprovidedtocalltheCATVsystem
installer'sattentiontoArticle820-22oftheNEC
thatprovidesguidelinesforpropergrounding
and,inparticular,specifiesthatthecableground
shallbeconnectedtothegroundingsystemof
thebuilding, asclosetothepointofcableentry
aspractical.
ATTENTION:POURPREVENIRLESCHOCS
ELECTRIQUESPASUTILISERCETTEFICHE
POLARISEEAVECUNPROLONGATEUR,UNEPRISE
DECOURANTOUUNEAUTRESORTIEDE
COURANT,SAUFSILESLAMESPEUVENTETRE
INSEREES A FOND SANS EN LAISSER AUCUNE
PARTIEA DECOUVERT.
Thelightningflashwitharrowhead,withinan
equilateraltriangle,isintendedtoalerttheuserto
thepresenceofuninsulated"dangerousvoltage"
withintheproduct'senclosurethatmaybeof
sufficientmagnitudetoconstitutea riskofelectric
shocktopersons.
CAUTION:TOPREVENTTHERISKOFELECTRIC
SHOCK,DONOTREMOVECOVER(ORBACK).NO
USER-SERVICABLEPARTSINSIDE.REFERSERVICING
TOQUALIFIEDPERSONNEL.
Theexclamationpointwithinanequilateraltriangle
isintendedtoalerttheusertothepresenceof
importantoperatingandmaintenance(servicing)
instructionsintheliteratureaccompanyingthe
appliance.
Theserialnumber,purchasedate,andMclntosh
LaboratoryServiceContractnumberareimportantto
youforpossibleinsuranceclaimorfutureservice.
Recordthisinformationhere.
SerialNumber
PurchaseDate
ServiceContractNumber
Uponapplication,MclntoshLaboratory
providesa ServiceContracttotheoriginal
purchaser.YourMclntoshAuthorized
ServiceAgencycanexpediterepairswhen
youprovidetheServiceContractwiththe
instrumentforrepair.
Copyright1987© byMclntoshLaboratoryInc.
1

Contents
INTRODUCTION
SIMPLIFIEDBLOCK
DIAGRAM
INSTALLATION
HOWTOCONNECT
FRONTPANELCONTROLS
USINGTHE
PUSHBUTTONS
PERFORMANCELIMITS
PERFORMANCECHARTS
TECHNICALDESCRIPTION
BLOCKDIAGRAM
4
5
6,7
8,9,10
11,12,13
14
15
16,17
18,19
20,21
YourC 34VAudio/VideoControlCenter
willgiveyoumanyyearsofsatisfactory
performance.Ifyouhaveanyquestions,
pleasecontact:
CUSTOMERSERVICE
MclntoshLaboratoryInc.
2ChambersStreet
Binghamton,NewYork13903-9990
Phone:[phone]
TakeAdvantageof3 years
ofContractService...
FillintheApplicationNOW.
MCINTOSHTHREEYEARSERVICECONTRACT
AnapplicationforA THREEYEARSERVICECONTRACTisincludedwiththismanual.
Thetermsofthecontractare:
1.Iftheinstrumentcoveredbythiscontract
becomesdefective,Mclntoshwillprovideallparts,
materials,andlaborneededtoreturnthe
measuredperformanceoftheinstrumenttothe
originalperformancelimitsfreeofanycharge.The
servicecontractdoesnotcoveranyshippingcosts
toandfromtheauthorizedserviceagencyorthe
factory.
2.AnyMcIntoshauthorizedserviceagencywill
repairallMclntoshinstrumentsatnormalservice
rates.Toreceivethefreeserviceunder theterms
oftheservicecontract,theservicecontractcer-
tificatemustaccompanytheinstrumentwhen
takentotheserviceagency.
3.Alwayshaveservicedonebya Mclntosh
authorizedserviceagency.Ifthe instrument is
modified or damaged as a result of unauthorized
repair the service contract will be cancelled.
Damagebyimproperuseormishandlingisnot
coveredbytheservicecontract.
4.Theservicecontractisissuedtoyouasthe
originalpurchaser.Toprotectyoufrom
misrepresentationthiscontractcannotbe
transferredtoa secondowner.
5.UnitsinoperationoutsidetheUnitedStatesand
CanadaarenotcoveredbytheMclntoshFactory
ServiceContract,irrespectiveoftheplaceof
purchase.NorareunitsacquiredoutsidetheUSA
andCanada,thepurchasersofwhichshould
consultwiththeirdealertoascertainwhat,ifany,
servicecontractorwarrantymaybeavailable
locally.
2

Thismanualwillhelpyoutoinstall,operate,and
understandyourAudio/VideoControlCenter.Readit
andbecomefamiliarwithittoenjoyittothefullest.
Mclntoshhasearnedworldrenownforitstechnolo-
gicalcontributionsforimprovedsound.Whenyou
boughtMclntosh,youboughtnotonlyhightechnology,
youboughttechnologicalintegrityprovenbytime.The
MclntoshAudio/VideoControlCenteristhenewest
evidenceofMclntoshtechnologicalintegrity.
Musicreproducinginstrumentsthatcarrythe
Mclntoshnamehavealwaysbeendesignedfortech-
nologicalleadershipandtomaintaintheMclntoshrepu-
tationforbestsound,fordurability,andforlonglife.
Mclntoshhasalwaysearnedtheforemostreputationfor
qualityperformance.Mclntoshhasprovideduserorient-
edfacilitiesandappearanceandMclntoshdesign
alwaysprovidesforeaseofmaintenanceorrepair.
Thesefundamentalelementsareincorporatedinthe
MclntoshAudio/VideoControlCenter,theeasiestto
operateyetmostcomplexever.
YourMclntoshC 34VAudio/VideoControlCenter,
aboveallotherswilldelivertoyouthebestsound,the
mostflexibility,andthegreatesteaseofuse.
TheMclntoshC 34Visa superbquality,highperform-
anceAudiocontrolcenter.WiththeMVS-1VideoSelec-
tor,theC 34Vwillprovidebothaudioandvideocontrol.
TheC 34Vhasmanyusefulfeaturestoenhanceyour
listeningandvideoenjoyment.Theyinclude:
1.A dualpreamplifiersystemthatprovidesseparate
listenandrecordprogramcontrol.Youmaylistentoor
viewoneprogramwhileyouarerecordinga different
program.WiththeMclntoshMVS-1VideoSelector,the
C34Vwillswitchvideoandaudiosignalsforviewing,
listening,andrecording.
2.Twoindependent,sevensourceinputselector
switchespermitdifferentaudio(orvideowiththe
MVS-1)programstobeselected.
3.A lownoise,electronicinputswitchingsystemadja-
centtotheinputjacksgivesgreatersourcetosource
isolation,lowaudiodistortion,andfreedomfromnoise
andhumpick-up.Theinputselectorelectronicswit-
chingsignalscontrolthevideoswitchingintheMVS-1.
4.Therecordmonitorswitchallowstherecordedpro-
gramtobeheardthroughtheMAINoutput,and,with
theMVS-1,therecordedvideosignalstobeseenona
TVormonitor.
5.A fivebandprogramequalizeradjustsandim-
provestheloudnesscontrastofthefivemostimportant
frequencyranges.Musicalbalancecanbeadjustedto
compensateforlistenerpreferences.
6.A precisionoutputvolumecontroliselectronically
trimmedduringmanufacturetomaintainchannelbal-
anceaccuracytoa fractionofa decibel(dB).Thishigh
orderofaccuracyassurescontinuingprogrambalance
asthevolumeischanged.
7.Anactivecircuitloudnesscontrol,iselectricallyin-
dependentofthevolumecontrol.Closeconformityto
theFletcher-Munsonequalloudnesscurvescan beat-
tained,regardlessofthevolumecontrolposition.
8.Highandlowfrequencyfiltersreducehighfre-
quencynoiseandlowfrequencyrumbleata 12dBper
octaverolloffrate.
9.A compandorexpandsorcompressesthedynamic
rangeoftheprogrammaterial.Compressedrecordings
andbroadcastscanbeexpandedtorestoredynamic
range.Tapescan becompressedandreplayedusingex-
pansiontoimprovesignal-to-noiseratio.
10.Frontpaneltaperecorderjackswhichallowsim-
pleplug-inofanadditionaltaperecorderwithout
disconnectingyourregularsystem.
4INTRODUCTION

SIMPLIFIEDBLOCKDIAGRAM5

PLAYERLOCATION
TheC34Vmaybeinstalledina Mclntoshcabinet
orcustominstalledinfurnitureofyourchoice.
Alwaysprovideadequateventilation.Thetrouble-free
lifeofanelectronicinstrumentisgreatlyextended
byprovidingsufficientventilationtopreventthe
buildupofhighinternaltemperaturesthatcause
deterioration.Allowenoughclearancesothatcool
aircanenteratthebottomofthecabinetandbe
ventedfromthetop.Therecommendedminimum
spaceforinstallationis155/8inches
(39.7cm)deep,17inches(43.2cm)wide,and8
inches(20.32cm)high.Never placeitaboveheat
generatingcomponents.
CUSTOMINSTALLATION
ThePANLOCsystemofinstallingequipment
convenientlyandsecurely,isa productofMclntosh
research.ThePANLOCbuttonsonthefrontpanel
willlocktheunitfirmlyinplacewhenturnedap-
proximatelyone-quarterturnclockwise.A
one-quartercounterclockwiseturnofthePANLOC
buttonsunlocksthechassisfromitsmounting.
Toinstalltheinstrumentina Mclntoshcabinet,
followtheinstructionsthatareenclosedwiththe
cabinet.Foranyothertypeofinstallationfollow
theseinstructions:
1.UnpackfromCarton
OpenthecartonandremovethePANLOCbrackets,
hardwarepackage,andmountingtemplate.Remove
theinstrumentfromitsplasticbagandplaceit
upsidedownontheshippingpallet.Unscrewthe
fourplasticfeetfromthebottomofthechassis.
2.MarktheCabinetPanel
Tapethemountingtemplateinpositiononthe
cabinetpanelwheretheinstrumentistobe
installed.Thebrokenlinesthatrepresenttheoutline
oftherectangularcutoutalsorepresenttheoutside
dimensionsofthechassis.Makesuretheselines
clearshelves,partitions,oranyequipment.Withthe
templateinplace,firstmarkthesixA andB holes
andthefoursmallholesthatlocatethecornersof
thecutout.Then,jointhefourcornermarkingswith
pencillines,usingtheedgeofthetemplateasa
straightedge.
3.DrillHoles
Usea drillwitha 3/16inch(5mm)bitheld
perpendiculartothepanelanddrillthesixA andB
holes.Then,usinga drillbitslightlylargerthanthe
tipofyoursawblade,drilloneholeateachoftwo
diagonallyoppositecorners.Theholesshouldbarely
touchtheinsideedgeofthepenciledoutline.Before
takingthenextstep,makesurethatthesixA andB
holeshavebeendrilled.
4.SawthePanelCutout
Sawcarefullyontheinsideofthepenciledlines.
Firstmakethetwolongcutsandthenthetwoshort
cuts.Aftertherectangularopeninghasbeencutout,
usea filetosquarethecornersandsmoothany
irregularitiesinthecutedges.
6INSTALLATION

5.InstalltheMountingStrips
Inthehardwarepackageyouwillfindtwomounting
strips,andtwosetsofmachinescrews.Forpanels
thatarelessthan1/2inch(12.7mm)thick,usethe
3/4inch(19.1mm)screws;forpanelsthataremore
than1/2inch(12.7rnrn)thick,usethe1-1/4inch(31.8
mm)screws.
Startingattheright-handsideofthepanel,inserta
screwoftheproperlengthintothecenterholein
thepanel,markedB onthetemplate.Onthebackof
thepanel,aligna mountingstripwiththeholesin
thepanelandtightenthescrewuntilthescrewhead
ispulledintothewood.
Repeatthisproceduretoattachthemountingstrip
totheleftsideofthepanel.
6.AttachthePANLOCBrackets
UsingtwoscrewsoftheproperlengthintheA holes
oneachside,attachthePANLOCbracketstothe
cabinetpanel;theshortflangeismountedagainst
thefront(face)ofthecabinetpanel.Thescrewspass
throughthePANLOCbracketflange,thecabinet
panel,andthenthroughthemountingstrips
previouslymounted.
thecabinet.TurnthePANLOCbuttons
counterclockwisetounlocktheinstrument.Itcan
thenslideoutwardtopermittheremovalofthe
instrumentfromthecabinet.
7.InstalltheInstrument
GuidetheACpowercordthroughthepanelopening
tothebackofthecabinet;then,slidetheinstrument
intotheopeningcarefullysothattherailsonthebot-
tomofeachsideofthechassisengagethetrackson
themountingbrackets.Continuetoslidethe
instrumentintothecabinetuntilthefrontpanelis
flushwiththecabinetpanel.TurnthePANLOC
buttonsatthelowerleftandrightcornersofthe
instrumentpanelclockwisetolocktheunitfirmlyin
INSTALLATION7

Foldoutthephotographsontheinsideoftheback
cover.Itwillassistyouinlocatingthecontrolsand
pushbuttons.Thenumbersandlettersonthephoto-
graphsrefertotheparagraphsthatfollow.
Therearefourfieldsofaudioconnectorsontheback
paneloftheC 34Vforusewithassociatedequipment:
AUDIOINPUTS,EXTERNALPROCESSORS,AUDIO
OUTPUTS,andMONITORAMPLIFIER.Onthefront
panelarefouradditionalphonejacks;twoforusewith
anadditionalaudiotaperecorderandtwoforusewith
headphones.
Useshieldedcablestointerconnectthesourceequip-
mentandthepreamplifier,Tominimizethepossibility
ofhumornoise,theshieldedcablesshouldbeof
parallelconstructionorifnotlooselytwisttheleftand
rightcablestogether.Locatethemawayfromthe
speakerconnectingcablesandACpowercords.Becer-
taintousegoodqualityshieldedcablesforallintercon-
nections.Yourdealercanadviseyouonthekindand
lengthofcablethatwillbestsuityourinstallation.
AUDIOINPUTS
1.TURNTABLE:
Connectthecablefromtheturntableleftchannel
totheLeftPHONOINPUT.Connectthecablefrom
theturntablerightchanneltotheRightPHONOIN-
PUT.Iftheturntablehasa separategroundlead,
connectittothescrewterminalmarkedground(GND).
2.TUNER:
Connectthecablefromthetunerleftchannel
outputtotheLeftTUNERINPUT.Connectthe
cablefromthetunerrightchanneloutputtothe
RightTUNERINPUT.
3.CD:
ConnectthecablefromtheCompactDisc(CD)
playerleftchanneloutputtotheLeftCDINPUT.
ConnectthecablefromtheCDplayerrightchannel
outputtotheRightCDINPUT.
4.TV:
Audiofroma stereoTVsetorTVmonitorcanbe
connectedtotheTVINPUT.Connecttheleftchan-
nelcabletotheLeftTVINPUT.Connecttheright
channelcabletoRightTVINPUT.
Theoutputofa monophonicTVsetcanbecon-
nectedtobothleftandrightchannelTVINPUTSby
useofa "Y"connector.
5.VCR1/TAPE1:
ToPlayback/Monitor:connectthecablefromthe
taperecorderleftchanneloutputtotheLeft
VCR1/TAPE1 INPUT.Connectthecablefromthe
taperecorderrightchanneloutputtotheRight
VCR1/TAPE1 INPUT.Connecta secondandthird
recorderinthesamemannertotheVCR2/TAPE2
INPUTandLASER/TAPE3INPUT.
ToRecord:connectthecablefromtheLeft
VCR1/TAPE1 OUTPUTtothelefthigh-levelinput
ofthetaperecorder.Connectthecablefromthe
RightVCR1/TAPE1 OUTPUTtotherightinputof
thetaperecorder.Connecta secondandthird
recorderinthesamemannertotheVCR2/TAPE2
OUTPUTandTAPE3 OUTPUT.
M.FRONTPANELTAPERECORDERJACKS:
TAPE3 recorderinputandoutputconnectionsare
alsoavailableattheTAPE3 IN-OUTphonejackson
thefrontpanel.Thefrontpanelphonejacksare
designedforusewith¼-inchstereophoneplugs.
Connectionsaretip:leftsignal,ring:rightsignal,
andsleeve:commonground.
Whena phoneplugisinsertedinthefrontpanel
TAPE3 inphonejack,thecircuittotherearpanel
LASER/TAPE3 INPUTisdisconnected,butinserting
aphonepluginthefrontpanelTAPE3 OUTphone
jackdoesnotdisconnecttherearpanelTAPE3
OUTPUT.Thus,itispossibletorecordfromthe
frontpanelTAPE3 OUTphonejackandtherear
panelTAPE3 OUTPUTatthesametimebutitis
notpossibletolistentobothatthesametime.
6.VCRI/TAPE1 - VCR2/TAPE2:
VideoTapeRecorders:Ifyouprefer,oneorboth
oftheVCR/TAPEinputscanbeusedfortheaudio
froma VCR.Connecttheleftchannelaudiooutput
fromtheVCRtotheLeftVCR1/TAPE1 INPUT.
Connecttherightchannelaudiooutputfromthe
VCRtotheRightVCR1/TAPE1 INPUT.IftheVCR
hasonlya singleaudiooutput(mono),usea "Y"
connectortoconnecttheprogramtoboththeleft
andrightinput.
7.LASERVISIONPLAYER:
Theaudiofroma laservisionvideodiscplayer
canbeconnectedtotheLASER/TAPE3 INPUTif
desired.Connectthecablefromtheleftchannel
audiooutputofa laserdiscplayertotheLeft
LASER/TAPE3 INPUT.Connectthecablefromthe
rightchannelaudiooutputofa laserdiscplayerto
theRightLASER/TAPE3 INPUT.
8.EXTERNALPROCESSORS:
ThesecondfieldofconnectorsaremarkedEXTER-
NALPROCESSORS.TherearetwosetsofEXTERNAL
PROCESSORjacks,onesetthataffectstheprogram
selectedbytheLISTENselectorandonesetthataf-
8HOWTOCONNECT

fectstheprogramselectedbytheRECORDselector.
Thesejacksareusedtoadda noisereductionor
anyaudiosignalprocessingdevice.Besureto
matchthelefttoleftandrighttorightchannels
whenconnectingexternalprocessors.
TheEXTERNALPROCESSORjackshaveswitching
contactswhichallowthesignaltopassthrough
themwhenthereisnothingpluggedintothejacks,
Whenanexternalprocessorisused,theprogramis
routedtotheexternalprocessorfromtheEXTER-
NALPROCESSORTOjackandbackbytheEXTER-
NALPROCESSORFROMjack.
WHENANEXTERNALPROCESSORISUSED,IT
MUSTBETURNEDONFORTHEPROGRAMTO
BEHEARDTHROUGHTHESYSTEM.
9.AUDIOOUTPUT:
ThethirdfieldofconnectorsaremarkedAUDIO
OUTPUT.Threesetsofjacks(VCR1/TAPE1,
VCR2/TAPE2,andTAPE3)connecttheprogram
selectedbytheRECORDinputselector.TheMAIN
setofjacksconnecttheprogramselectedbythe
LISTENinputselectorandconnecttothepower
amplifier.Outputtothetwosetsofjacks(SWITCH-
ED1 andSWITCHED2)controlledbythefrontpanel
SPEAKER/OUTPUT1 and2 pushbuttonscanbecon-
nectedtoadditionalpoweramplifiersforremote
arealistening.
TheLeftMAINjackistobeconnectedtothe
amplifierleftinputjack.TheRightMAINjackisto
beconnectedtotheamplifierrightinputjack.
Twoadditionalstereopoweramplifiersmaybe
connectedinthesamefashiontotheSWITCHED
OUTPUTjacks.Audiooutputsignalissuppliedto
thesejacksonlywhenthefrontpanelpushbutton
SPEAKER/OUTPUT1 and/or2 pushbuttonsare
pressedin.Thisarrangementisusefultoturnthe
programonorofftoitsseparateamplifiersand
loudspeakers.
10.MONITORAMPLIFIER:
TheMONITORAMPLIFIERprovidespowerto
headphones.Itmayalsobeusedtodrivespeakers.
TheMONITORAMPLIFIERwillfurnish20wattsper
channelacross8 ohmsor12.6voltsRMStoa 600
ohmline.Foroperation,seeMONITORAMPLIFIER
page13.
TheinputtotheMONITORAMPLIFIERcanbe
selectedfromeithertheRECORDprogram,the
LISTENprogram,orfroma thirdsourceconnected
totheEXTernalINPUTjacksontherearpanel.The
inputselectorswitchisonthetoppaneloftheC 34V.
TheEXTernalINPUTMaybeusedforprogram
sourcesnotoriginatingintheC 34V.Oneusecould
betoconnecttheoutputofa timedelaydevicefor
backchannelspeakers.
TheoutputoftheMONITORAMPLIFIERisfedto
thefrontpanelHEADPHONEphonejacks,tothe
redandblackposicontact pushconnectorsandto
thejacksmarkedOUTPUT.Connecttheleft
speakerleadtotheblackCOMmonpushconnector
andtheredL terminal.Connecttherightspeaker
leadtotheblackCOMmonpushconnectorandthe
redRterminal.
TheOUTPUTjackscanbeconnectedtodrivea
lowimpedance(8to600W)unbalancedline.
11.GROUND:
Theground(GND)postontherearpanelispro-
videdprimarilyfora turntableorrecordchanger
thathasa separategroundleadinadditiontothe
signalleads.
12.ACPOWER:
PlugthepreamplifierACpowercordintoa 120
volt60Hzwalloutlet.Theplugbladesarepolariz-
edsobecertaintheplugisfullyinsertedinthe
outlettopreventbladeexposure.
CAUTION:TOPREVENTELECTRICSHOCK,DO
NOTUSETHE(POLARIZED)PLUGONTHISUNIT
WITHANEXTENSIONCORD,RECEPTACLE,OR
OTHEROUTLETUNLESSTHEBLADESCANBE
FULLYINSERTEDTOPREVENTBLADEEXPOSURE.
ThreetypesofACpoweroutletsareprovidedon
thebackpaneloftheC 34V.Threeareblack,two
arered,andoneisgreen.
Theblackoutletsareswitchedonoroffwhenthe
C34Visturnedonandoff.UsethesetoprovideAC
powertoamplifiers,CDplayers,orotheraccessories.
Thepowercapacityofalltheoutlets,totalled,is1440
watts.Thegreenoutlethasa maximumcapacityof
100watts.Forpowerconsumptionabove1440watts,
itisnecessarytoadda MclntoshSCR2 (SPEAKER
CONTROLRELAY).TheSCR2 hastwoACpower
outletsthatprovideadditionalcapacityof1800watts
switchedonoroffbytheC 34V.Usetheseoutletsto
supplyACpowertoamplifiersorothercomponents
wheneverthetotalloadtobeswitchedexceedsthe
C34Vratingof1440watts.
Theredoutletsareonatalltimesandareused
withaccessoriesthathavetheirownpowerswitches.
Forexample,a VCRshouldbepluggedintooneof
theseoutletsforittobeabletorecordTVprograms
whenthemainaudiosystemisturnedoff.
HOWTOCONNECT9

ThegreenACpoweroutletisonatalltimesand
isusedforturntablepower.Donotusethisoutlet
foranyotherpurpose.Whentheturntablepower
cordispluggedintothegreenACoutlet,theturn-
tablecanbeusedasanalternatewaytoswitchthe
ACpowertotheentiresystemonoroff.Whenthe
turntablepoweristurnedon,a sensorcircuitinthe
C34Vwilldetectthecurrentdrainoftheturntable
motorandwillturnontheC 34Vthesamewaythe
redPOWERpushbuttondoes.Theredpower
pushbuttonmustbeintheOFForoutposition.As
longasa turntableisconnectedtothegreenAC
outlet,theturntablecurrentwillalwaysoverridethe
redPOWERpushbuttonandturnthesystemon.
Someturntablesdrawthesameorverynearlythe
samecurrentwhetheronoroff.AUTOTURN-ON
controlisnotpossiblewiththistypeofturntable.
UseoneoftheredunswitchedACoutletsinsteadof
thegreen.
13.FUSE:
A1.0AMPfast-actingfuseprotectstheC 34V
turntablecurrentsensingcircuitsandthegreenAC
turntableoutlet.Thisfusemustbereplacedwiththe
sametypeandrating1.0AMPfast-actingfuse.Do
notuseSLOBLOfuses.Thefusedoesnotprotect
equipmentconnectedtotheblackACoutlet.
14.OPTIONALACCESSORIES:
ADDITIONALACPOWERANDSPEAKER
SWITCHINGWITHTHESPEAKERCONTROL
RELAY
TheSPEAKERCONTROLRELAY,orSCR2,is
designedtoprovidebothspeakercontrolswitching
andhighpowerswitchedACoutlets.
TheSCR2 alsohastwoACpoweroutletsthat
provideadditionalcapacityof2400wattsswitched
bytheC 34V.UsetheseoutletstosupplyACpower
toamplifiersorothercomponentswhenthetotal
loadswitchedexceedstheC 34Vratingof1440
watts.Plugthe4-prongplugonthecableattached
totheSCR2 intotheSCR2 socketontherearof
theC 34V.PlugtheSCR2 heavy,ACpowerline
corddirectlyintoa walloutlet.Donotplugitinto
theC 34V.WhentheC 34Visturnedon,power
fromtheC 34Vwillenergizea relayintheSCR2
whichconnectsthetwoSCR2 ACoutletsdirectlyto
thewalloutlet.
Twoloudspeakerscanbeturnedonoroffwiththe
SCR2 byusingthefrontpanelpushbuttonsSPEAK-
ER/OUTPUT 1 and2.UsetheTO MAIN SPEAKERS
terminalstriptoconnectthemainlisteningpairof
speakersandTOREMOTESPEAKERterminaltoa
remoteareapairofspeakers.Connectthepower
amplifieroutputtoFROMPOWERAMPLIFIERter-
minalstrip.Maintainleftandrightorientationand
likepolarity.Pushbutton SPEAKER 1 will turn the
mainspeakersonoroffandSPEAKER2 pushbutton
willturntheremotespeakersonoroff.
15.VIDEOSELECTOR:
TheMclntoshVIDEOSELECTOR,MVS-1,is
designedtoenabletheC 34Vtocontrolvideopro-
gramsaswellasaudio.TheMVS-1connectstothe
VIDEOSELECTORcomputer-typeconnectoronthe
rearoftheC 34V.Followtheinstructionpacket
withtheMVS-1forconnectingthevideocables,
10HOWTOCONNECT

Foldoutthephotographsontheinsideoftheback
cover. It will assist youin locating the controls and
pushbuttons.Thelettersonthephotographsreferto
theparagraphsthatfollow.
BeforeattemptingtooperateyourC 34VAudio/Video
ControlCenter,familiarizeyourselfwiththecontrols
andwhattheydo.
A.LISTENANDRECORDSELECTORSWITCHES
TheLISTENInputselectorswitchislocatedatthe
upperleftonthefrontpanel.Itisusedtoselectthe
inputfortheLISTENprogramline.Theselectedpro-
gramsourceisfedtotheMAINoutput.
TheRECORDinputselectorswitchislocatedat
thelowerleftonthefrontpanel.Itisusedtoselect
theinputfortheRECORDprogramline.The
selectedprogramsourceisfedtotheTAPE1,TAPE
2,andTAPE3 outputs.TheRECORDandLISTEN
switchesoperatetotallyindependentlyofeachother
andwithoutanyinterference.
B.MODESELECTOR
TheMODESELECTORallowsyoutoidentifyeach
stereochannel,createmonophonicprogram
material,anddirectprogrammaterialtoonechan-
nelortheother.TheMODESELECTORoperates
onlyintheLISTENprogramline.
Itcontrolstheprograminsevenways:
LTOL&R:Connectstheleftinputtobothleftand
rightoutputcircuits.
RTOL&R:Connectstherightinputtobothleft
andrightoutputcircuits.
STEREOREV:Connectstheleftinputtotheright
outputcircuitandtherightinputtotheleftoutput
circuit.
STEREO:Connectstheleftinputtotheleftoutput
circuitandtherightinputtotherightoutputcircuit.
UsetheSTEREOpositionfornormallistening.
MONO(L+ R):Addsthelefttotherightinput
andconnectsthecompositetobothleftandright
outputcircuits.
L+ R TOL:Connectstheleftplusrightprogram
totheleftoutputcircuitonly.
L+ R TOR:Connectstheleftplusrightprogram
totherightoutputcircuitonly.
C.EQUALIZERFREQUENCYCONTROLS
EachoffiveEQUALIZERFREQUENCYcontrols
raisesorlowerstheamplitudeofa bandoffrequen-
ciescenteredonthefrequencymarkedabovethe
control.Bothleftandrightchannelsareaffected.
Thecenter,orflatpositionofthecontrolhasa de-
tentforeasyreference.Inthecenterordetentposi-
tion,theentirecircuitforthatcontrolisremoved
fromtheprogramcircuitbygroundingthecontrol
electronically.Theresultisthe"straightwirewith
gain"ortheflexibilityofcompletemusicalbalanc-
ingtoyourtaste.
UsetheEQUALIZERFREQUENCYcontrolsto
modifythesoundandbalanceofprogrammaterial.
Herearesomesuggestions:
Adjustmentto__EqualizerCorrection
Makedeepbasslouder
Makeallbasslouder
Reinforcevoices
Humon program
Brightenviolins
andtrumpets
Emphasizecymbals
Raise30
Raise30and150
Lower150andraise500
Reduce30and150
Raise1500
Raise10K
TheEQUALIZERFREQUENCYcontrolscanbe
switchedtoeithertheLISTENorRECORDprogram
linesbytheRECORDEQUALIZERpushbutton.
BecausetheequalizerisinthecircuitaftertheCOM-
PANDOR,useoftheequalizerwillnotaffecttheper-
formancecharacteristicsoftheCOMPANDOR.
D.BALANCEANDLOUDNESS
TheBALANCEandLOUDNESScontrolsarecon-
centric.TheBALANCEcontrol(largeouterknob)
adjuststhevolumeofthechannelsrelativetoeach
other.
L-left...turningthecontroltotheleftaccentsthe
leftchannelbyreducingtherightchanneloutput.
R-right...turningthecontroltotherightaccents
therightchannelbyreducingtheleftchannel
output.
E.LOUDNESS
TheLOUDNESScontrol(smallcenterknob)pro-
videsfrequencyresponsecontouredtocompensate
forthebehaviorofthehumanearatlowerlistening
levels.Thiscontourisaccuratelymodeledafterthe
familyof"equalloudness"curvesidentifiedbyFlet-
cherandMunson.Atthefullycounterclockwise
detentedFLATposition,theloudnesscontouris
electricallyflat.Asthecontrolisturnedclockwise,
bothbassandtreblefrequenciesincreaseinthe
correctproportion.Thecontourisnotaffectedby
differentsettingsoftheVOLUMEcontrol.Afterset-
tingtheVOLUMEcontrolforthedesiredlistening
level,adjusttheLOUDNESScontrolfortheprefer-
redcompensation.
F.COMPANDORSYSTEM:
TheMclntoshCOMPANDORSystemcanbeused
tocontrolthedynamicrangeofprogrammaterial.It
canbeusedintwodifferentways:tofunctionasan
FRONTPANELCONTROLS11

expanderorasa compressor.Expansioncanrestore
thedynamicrangelimitedbytheprocessofrecord-
ingbothrecordsandtapeorbroadcastingofmusic.
Compressiondecreasesdynamicrange.Itcanbe
usedformakingtaperecordingsorforlisteningto
backgroundmusic.TheCompandorcanbe
switchedtoeithertheRECORDorLISTENlines,by
meansoftheCOMPANDORpushbutton.
TheCompandorSystemhasfourcontrols.The
concentricthree-positionCOMPANDORswitchand
RATIOcontrolarelocatedonthefrontpanel.The
LEVELMATCHcontrolandSPEEDselectorarelo-
catedontheC 34Vtoppanel.
COMPANDORSELECTOR
TheouterCOMPANDORknobcanbesettoEX-
PAND,OFF,orCOMPRESS.WhentheCOMPAN-
DORswitchisinEXPANDorCOMPRESS,a red
lightwillappearabovetheLISten-orRECordCOM-
PANDORpushbutton.InthecenterOFFposition,
theCompandorSystemisswitchedoutofthecircuit
andthelightswillbeout.WhentheCompandoris
notused,theselectorshouldbeplacedintheOFF
position.
RATIOCONTROL
TheinnerRATIOknobisusedtocontrolthe
amountofexpansionorcompression.
LEVELMATCH
TheLEVELMATCHcontrolonthetoppanelis
usedtoadjustthelisteninglevelwhentheexpander
orcompressorisswitchedinoroutofthecircuit.
SPEED
TheSPEEDselectoronthetoppanelisusedto
controltherateatwhichtheCompandorSystemre-
spondstosignals.ByswitchingfromFASTtoNOR-
MALtoSLOW,a moregradualrateofchangeinex-
pansionorcompressionoccurs.Formusicwithper-
cussiveinstruments,suchaspiano,drums,guitar,
etc.,useNORMALorFAST.IntheFASTmode,the
CompandorSystemfollowschangesquicklybutwill
tracklowfrequencieslessaccurately.Non-
percussivemusicandvoicerequireslowerspeed.
AtSLOWspeedthelowfrequencytrackingisac-
curate,buttherateofresponseisslower.TheNOR-
MALpositionisbestsuitedformostprogram
material.
USINGTHECOMPANDORASANEXPANDER
WhentheCOMPANDORselectorswitchisinthe
EXPANDposition,theRATIOcontrolisusedto
selecttheamountofexpansion.Fullcounterclock-
wiserotationcorrespondstoa ratioof1.0.This
meansthatthedynamicrangeoftheexpanderout-
putisthesameasthedynamicrangeofitsinput.
WiththeVOLUMEcontrolata normallistening
level,theRATIOcontrolisturnedclockwise,the
outputdynamicrangebecomesgreaterthanthein-
put.SettheRATIOcontroltothedesiredexpansion
(usuallybetween1.2and1.5).Nowswitchthe
COMPANDORselectorknobbetweenEXPANDand
OFF.A changeintheaveragelisteninglevelwill
usuallybeheard.AdjusttheLEVELMATCH(onthe
toppanel)controluntiltheaveragelisteninglevels
matchascloselyaspossiblewheninEXPANDand
OFF.Afterthisadjustment,youwillnoticethatwith
the expander on, loud passages will be louder and
softpassageswillbesoftertendingtomakeany
backgroundnoisequieter.
WhentheRATIOcontrolisatthefullyclockwise
position,itcorrespondstoa ratioof2.0.Theoutput
dynamicrangeisthentwicetheinputdynamic
range.Thissettingisextremeformostprogram
material.
USINGTHECOMPANDORASA COMPRESSOR
WhentheCOMPANDORselectorswitchisinthe
COMPRESSposition,theRATIOcontrolisusedto
selectthereductionindynamicrangedesired.Full
counterclockwiserotationcorrespondstoa ratioof
1.0.Thecompressoroutputandinputdynamic
rangewillbethesame.SettheVOLUMEcontrolto
anormallisteninglevel.AstheRATIOcontrolis
turnedclockwise,theoutputdynamicrangebe-
comeslessthantheinputrange.SettheRATIO
controltothedesiredamountofcompression.
SwitchtheCOMPANDORselectorknobbetween
COMPRESSandOFF.A changeintheaveragelis-
tening level will usually be heard.Adjust the LEVEL
MATCHcontroluntiltheaveragelisteninglevels
matchascloselyaspossiblewhenswitchingbe-
tweenCOMPRESSandOFF.Afterthisadjustment,
youwillnoticethatwithCOMPRESSon,loud
passageswillbesofterandsoftpassageswillbe
louder.
WhentheRATIOcontrolisatthefullyclockwise
positionitcorrespondstoa ratioof2.0.Theoutput
dynamicrangeisthenonehalfoftheinputrange.
Thissettingcanbeusefultocreatehighlycompress-
edtaperecordingsparticularlyusefulinnoisyloca-
tionssuchasautomobiles,etc.
Twoexamplesforusingtheexpanderare:
1.Toreducebackgroundnoise(hum,hissor
scratch):
a.Selectthedesiredprogramsourcewiththe
12FRONTPANELCONTROLS

LISTENinputselector.
b.IncreasetheVOLUMEcontrolduringa quiet
passageoftheprogramuntilnoiseisclearlyaudible.
c.TurntheCOMPANDORselectorknobtoEX-
PAND.TheListenindicatorwilllightoverthe
COMPANDORpushbutton.
d.RotatetheRATIOcontrolclockwiseuntilthe
noiseisacceptablyreduced.
e.AdjusttheLEVELMATCHcontrolas
previouslydescribed.
2.Toimprovethesoundofrecordedorbroadcast
programmaterial:
a.SelecttheinputontheLISTENinputselector.
b.IncreasetheVOLUMEtoa satisfactorylevel.
c.TurntheCOMPANDORselectorswitchto
EXPAND.
d.RotatetheRATIOcontrolclockwiseuntilthe
dynamicrangeofthemusicissatisfactoryforyou.
Theusualpositionwillbebetween1.2and1.5.
e.AdjusttheLEVELMATCHcontrolas
previouslydescribed.
TOPPANELCONTROLS
COMPANDOR
OperationoftheLEVELMATCHandSPEEDcontrols
isexplainedonpage12.SeetheCompandorSystem
description.
MONITORAMPLIFIER
Thebuilt-inMONITORAMPLIFIERcandrivehead-
phones,loudspeakers,orprovidea lowimpedanceline
output.A toppanelinputpositionswitchselectsthein-
putfortheMONITORAMPLIFIER.Thesourcesarethe
LISTENprogramline,theRECORDprogramline,orany
highlevelEXTERNALsource.Whenusingheadphones
pluggedintothefrontpaneljacks,thenormalposition
isLISTEN.
ThemonitoramplifierLEFTandRIGHTCAINcontrols
arelocatedtotheleftoftheINPUTswitchonthetop
panel.WhentheswitchisintheLISTENposition,the
LEFTandRIGHTGAINcontrolsregulatethemonitor
volumealongwiththemainfrontpanelVOLUMEcon-
trol.WhentheINPUTswitchisintheRECORDorEX-
TERNALposition,onlytheLEFTandRIGHTGAINcon-
trolsregulatethemonitoramplifiervolume.
Themonitoramplifiercanbeusedwithany lowim-
pedancedynamicheadphones.Highimpedancehead-
phoneswillworkbutatreducedlisteninglevels.
FRONTPANELCONTROLS13

G.COMPANDOR
TheCOMPANDORpushbuttonswitchesthe
COMPANDORcircuitsbetweentheLISTEN(out
position)andRECORD(inposition)programlinesor
disconnectsthecircuitentirely.A redlightemitting
diode(LED)illuminatestoindicatewhenthecircuit
isconnectedtoeitherListenorRECord.When
neitherislit,theCOMPANDORselectorknobis
turnedtotheOFFposition.
H.RECordEQUAL
TheEQUALIZERFREQUENCYpushbuttoncon-
nectsthesecontrolstotheLISTENorRECORDpro-
gramlines.Whenthepushbuttonisout,the
EQUALIZERFREQUENCYcontrolsareconnectedto
theLISTENline,andtheredLEDindicatorabove
thebuttonisoff.Whenthepushbuttonisin,they
areconnectedtotheRECORDline.TheredLEDin-
dicatorwillbeon.Thenormalpositioniswiththe
pushbuttonout.
1.RECordMONITOR
Tomonitorwhilerecordingwitha three-head
taperecorder,settheLISTENinputselectortothe
properTAPEposition.TheRECordMONITORLED
indicatorisoffwhenlisteningtotheprogram
recordedonthetapeandonwhenlisteningtothe
programsourcebeingfedtothetaperecorder.
J.LFFILTER
TheLowFrequencyFILTERisintheLISTENpro-
gramlineonly.Whenthepushbuttonisout,the
filterisoutofthecircuitandtheredindicatorlight
willbeoff.Whenthepushbuttonisin,theLFFIL-
TERisinthecircuitandtheredlightwillbeon.
Thefilteriseffectiveforallfrequenciesbelow50Hz
andattenuatesattherateof12dBperoctave.Use
ittoreduceundesirablelowfrequencynoisesuch
asrumbleormechanicalfeedback.
K.HFFILTER
TheHighFrequencyFILTERisintheLISTENpro-
gramlineonly.Whenthepushbuttonisout,theHF
FILTERisoutofthecircuitandtheredindicator
lightisoff.Whenthepushbuttonisin,theHFFIL-
TERisinthecircuitandtheredlightison.The
filteriseffectiveforallfrequenciesabove7,000Hz
andattenuatesattherate of12dBperoctave.Use
ittoreduceundesirablehighfrequencynoisesuch
asrecordsurfacenoiseortapehiss.
L.SPEAKER/OUTPUT1 and2
TheSPEAKER/OUTPUT1 and2 pushbuttonscan
beusedtoswitchonoroffeithertheAUDIOOUT-
PUTSWITCHED1 and2 jacksorthemainand
remotespeakerswhenanoptionalSpeakerControl
Relay(SCR2)isused.
TheSWITCHED1 and2 jacksontherearpanel
oftheC 34VhavethesameprogramastheMAIN
OUTPUT.WhenoneorbothSPEAKER/OUTPUT
pushbuttonsareIN,theLISTENprogramlineiscon-
nectedtothecorrespondingpairofOUTPUTjacks
andtheLEDindicatoristurnedon.Programto
otherdevicescanbecontrolledsuchasrearchan-
neldelay,reverberation,etc.Example:connectthe
SWITCHED1 jacktotheinputofa reverberation
deviceandtheoutputofthereverberationdevice
totheinputC 34VMONITORAMPLIFIERandthe
outputoftheMONITORAMPLIFIERtoa setofrear
loudspeakers.(Themonitoramplifierswitchmustbe
intheEXTERNALposition.)Rearchannelreverbera-
tioncanthenbeswitchedonoroffbytheSPEAKER
OUTPUT1 pushbuttonwithouttheneedforanad-
ditionalamplifier.
N.POWERON
TheredpushbuttonturnstheC 34Vonoroff.
Whenthepowerison,thepanelilluminatesand
theredlightabovethispushbuttonwillgoon.The
turntablecanalsobeusedasa powerswitch.See
page10.
14PUSHBUTTONS

PERFORMANCELIMITS
Performancelimitsarethemaximumdeviationfrom
perfectionpermittedfora Mclntoshinstrument.We
promiseyouthatwhenyoupurchasea newC 34Vfrom
aMclntoshfranchiseddealer,itwillbecapableofor
canbemadecapableofperformanceatorexceeding
theselimitsoryoucanreturntheunitandgetyour
moneyback.Mclntoshistheonlymanufacturerthat
makesthisstatement.
PREAMPLIFIERSECTION
FREQUENCYRESPONSE
+0,-0.5dBfrom20Hzto20,000Hz
MAXIMUMVOLTAGEOUTPUT
10voltsfrom20Hzto20,000Hz
TOTALHARMONICDISTORTION
0.01%maximumfrom20Hzto20,000Hz
atratedoutput
SENSITIVITY
Phono-2mVfor2.5Vratedoutput
(0.4mVIHF)
HighLevel-250mVfor2.5Vratedoutput
(50mVIHF)
SIGNALTONOISERATIO,A-WEIGHTED
Phono-90dBbelow10mVinput
(84dBIHF)
HighLevel-100dBbelowratedoutput
(86dBIHF)
MAXIMUMINPUTSIGNAL
Phono-100mV
HighLevel-10volts
INPUTIMPEDANCE
Phono-47kohmsand65pfcapacitance
HighLevel-50kohms
EQUALIZATIONCONTROLS
Variable12dBboostto12dBcutatcenterfrequen-
ciesof30,150,500,1500,10kHz
COMPANDORRATIOS
From1:2compressionto2:1expansion
LFFILTER
Flatorroll-offat12dBperoctavebelow50Hz.
HFFILTER
Flatorroll-offat12dBperoctaveabove7,000Hz.
MONITORAMPLIFIERSECTION
CONTINUOUSAVERAGEPOWEROUTPUT
20wattsperchannelinto8 ohms,from20Hzto
20kHz,at0.01%maximumharmonicdistortion
FREQUENCYRESPONSE
+0 -0.2dBfrom20Hzto20,000Hz
SENSITIVITY
750mVforratedoutput(170mVIHF),inputim-
pedanceis27Kohms
SIGNALTONOISERATIO,A-WEIGHTED
100dBbelowratedoutput(87dBIHF)
GENERALINFORMATION
SEMICONDUCTORCOMPLEMENT
31BipolarTransistors
76FieldEffectTransistors
35IntegratedCircuits
107Diodes
1SiliconControlledRectifier(SCR2)
ACPOWEROUTLETS
1greenturntablecurrentsensing,100watts
2redunswitched
3blackswitched
1440wattstotalcapacity
POWERREQUIREMENTS
120volts,50/60Hz,25to85watts
MECHANICALINFORMATION
SIZE:
16-1/8incheswide(40.6cm)by5-7/16incheshigh
(13.8cm)by13inchesdeep(33cm),fromthe
mountingsurface,includingPANLOCshelfandback
panelconnectors.Knobclearancerequiredis1-1/4
inches(3.2cm)infrontofthemountingpanel.
FINISH:
Frontpanelisanodizedgoldandblackwithspecial
gold/tealnomenclatureillumination.Chassisisblack.
MOUNTING:
ExclusiveMclntoshdevelopedprofessionalPANLOC
WEIGHT:
26pounds(11.8kg)net,38pounds(17.2kg)in
shippingcarton
PERFORMANCELIMITS15

16PERFORMANCECHARTS

PERFORMANCECHARTS17

Thesimplifiedblockdiagramonpage5 andthede-
tailedblockdiagramonpages20and21showhowthe
C34Vinternalcircuitsarearranged.TheC 34Vuses
separateprogramchannels(referredtoas"program
lines"inthismanual)for"listening"and"recording".
Thisallowsyoutolistentoanyprogramsourcewhile
yourecordfromanotherorthesameprogramsource.
Themodeselector,volumecontrol,loudnesscontrol,
balancecontrol,andLFandHFfiltersareinthelisten
programlineonly.Thecompandor,thefiveequalizer
frequencycontrols,andthemonitoramplifiercanbein-
dividuallyswitchedtothelistenprogramlineorthe
recordprogramline.
PHONOAMPLIFIER
Thisamplifierusesa hightechnologyintegratedcircuit
operationalamplifier.Itsdifferentialinputstagehas
beenoptimizedforlownoiseandlowdistortionperfor-
mance.Openloopgainofthisintegratedcircuitis
100,000times.Withhighopenloopgaina large
amountofnegativefeedbackisusedaroundthephono
amplifiertofurtherreducenoiseanddistortion.The
feedbacknetworkalsoprovidesprecisionRIAAfrequen-
cycompensation.Thenetworkuses1%metalfilmresis-
torsand5%polyfilmcapacitors.Toachievelownoise
performanceitisessentialthatthefeedbacknetwork
haveverylowimpedance.Asa consequence,thepre-
amplifiermustbecapableofoperatingasa power
amplifiertodrivethisimpedance.Theactualpowerout-
putcapabilityofthispreamplifierstageismorethan100
milliwatts,a greatmarginbeyondthatwhichisre-
quired.
Inputsensitivityofthephonoamplifieris2.2milli-
volts.Thegainoftheamplifieris42dBat1000Hz.The
phonoamplifierhasa verywidedynamicrange.At
1000Hzthephonoinputcircuitwillaccept100milli-
voltswithoutoverload,a voltagefargreaterthanthe
outputofanymagneticphonocartridgepresently
available.
LISTENANDRECORDSELECTORSWITCHES
Inputswitchingisaccomplishedelectronically.Signals
fromthe7 inputsconnecttotwoarraysofFieldEffect
Transistors(FET)toperformtheswitching.Control
signalsfromthelistenandrecordselectorswitchesturn
ontheappropriateFETswitchestopasstheselectedin-
putsignals.Theotherinputsignalsareblockedbythe
"off"FETswitches.EachFETswitchusestwocascaded
FETtransistorstoprovidetherequiredisolationandpre-
ventcrosstalkbetweeninputs.TheFET"on"resistance
isverylowwhichpreventsdistortion.Theswitching
transistorsarelocatedrightattheinputjacks,sothat
signalwiringiskepttoa minimumwhicheliminates
crosstalkandnoiseproblems.
LISTENPROGRAMLINE
ThelistenprogramsignalfromtheLISTENinput
switchgoestotheCOMPANDORcontrolswitching
wheretheCOMPANDORcanbeinsertedineitherthe
listenortherecordprogrampath.TheCOMPANDOR
circuitisdescribedlater.
ThelistenprogramthengoestotheLISTENEXTER-
NALProcessorjacks.WhenanEXTERNALPROCESSOR
isused,thelistenprogramleavestheC 34Vthroughthe
EXTERNALprocessorTOjackandreturnsviatheFROM
jack.Ifa processorisnotused,thesignalpassesdirectly
throughtheswitchingcontactsInthejacks.
Thevolumecontrolisnextinthelistenpath.Itisa
stepattenuatorwithlefttorighttrackingaccuracybetter
than1 dBthroughoutitsentirerange.Suchextremely
accuratematchingisachievedthroughelectronically
controlledtrimmingoftheresistancematerialdeposited
onpairsofprintedcircuitswithinthecontrol.Sincethe
switchcommutatortouchesonlycontactpadsandnot
theactualresistanceelement,trackingaccuracyisnot
degradedwithuseasinordinaryvolumecontrols.
Theloudnesscontrolanditsamplifiersfollowthevol-
umecontrol.Inthepast,loudnesscontrolshavetypi-
callybeensimplepassivecircuitsconnectedtoa tapon
thevolumecontrol.Asa consequence,compensation
accuracywasdependentonmanyvariablessuchas
volumecontrolpositionanddifferencesintheinput
level.TheC 34Vloudnesscontrolusesactivecircuitsof
anintegratedcircuitoperationalamplifierwithtwofeed-
backloops.Onehasflatfrequencyresponse,whilethe
otherhasresponseconformingtotheFletcher-Munson
equalloudnesscontours.A potentiometerisplacedbe-
tweenthesetwofeedbackloopsmakingitpossibleto
selectanycombinationofthetwo,froma flatresponse
tofullloudnesscompensation.Theoverallgainofthe
stageis20dBatmid-frequenciesandtheaveragelisten-
ingvolumeisnotaffectedbythepositionofthe
loudnesscontrol.
Thelistenprogramsignalsnextpasstothebalance
controlandthentotheequalizeramplifiercomposedof
alownoiseoperationalamplifierwithflatresponseand
unitygain.Fiveotheroperationalamplifiersarearrang-
edincircuitconfigurationsthatareequivalenttofive
seriestunedcircuits,eachatoneoftheequalizerfre-
quencies.Theseseriestunedcircuitsareinsertedvia
controlpotentiometersintoeithertheinputcircuitor
feedbackcircuitoftheequalizeramplifiertoprovidea
boostorcutcapabilityof12dBforeachequalizerband
18TECHNICALDESCRIPTION