McIntosh C30 User manual

039493
C30
STEREO
PREAMPLIFIER

VARIOUSREGULATORYAGENCIES
REQUIRETHATWEBRINGTHE
FOLLOWINGINFORMATIONTO
YOURATTENTION.PLEASEREADIT
CAREFULLY.
WARNING:TOPREVENTFIREORSHOCK
HAZARD,DONOTEXPOSETHISUNITTO
RAINORMOISTURE.
CAUTION:TOPREVENTELECTRICSHOCK
DONOTUSETHE(POLARIZED)PLUGON
THISUNITWITHANEXTENSIONCORD,
RECEPTACLEOR OTHEROUTLETUNLESS
THEBLADESCANBEFULLYINSERTED
TOPREVENTBLADEEXPOSURE.
Theserialnumber,purchasedate,andMclntosh
LaboratoryServiceContractnumberareimportant
toyouforpossibleinsuranceclaimorfutureservice.
Recordthisinformationhere.
SerialNumber
C30
STEREO
PREAMPLIFIER
Purchasedate
ServiceContractNumber
Uponapplication,MclntoshLaboratoryprovidesa
ServiceContracttotheoriginalpurchaser.Your
MclntoshAuthorizedServiceAgencycanexpedite
repairswhenyouprovidetheServiceContractwith
theinstrumentforrepair.
039493
1

YourC 30StereoPreamplifierwill
giveyoumanyyearsofpleasantand
satisfactoryperformance.Ifyou
haveanyquestions,pleasecontact:
Contents
CUSTOMERSERVICE
MclntoshLaboratoryInc.
2ChambersStreet
Binghamton,NewYork13903-9990
Phone:[phone]
TakeAdvantageof3 years
ofContractService...
FillintheApplicationNOW.
INTRODUCTION3
INSTALLATION4&5
HOWTOCONNECT6,8 & 9
CONNECTINGDIAGRAMS...7,10& 11
THEFRONTPANELCONTROLS
andHOWTOUSETHEM. . 12,13& 14
REARPANELCONTROLS15
PERFORMANCELIMITS
andRATINGS16
PERFORMANCECHARTS17& 18
TECHNICALDESCRIPTION19& 20
BLOCKDIAGRAM22& 23
AnapplicationforA THREEYEARSERVICECONTRACTisincludedwiththismanual.
Thetermsofthecontractare:
1.Mclntoshwillprovideallparts,materials
andlaborneededtoreturnthemeasured
performanceoftheinstrumenttothe
originalperformancelimits.TheSER-
VICECONTRACTdoesnotcoverany
shippingcoststoandfromtheauthoriz-
edserviceagencyorthefactory.
2.AnyMclntoshauthorizedserviceagency
willrepairMclntoshinstrumentsatnor-
malservicerates.Toreceiveservice
underthetermsoftheSERVICECON-
TRACT,theSERVICECONTRACTCER-
TIFICATEmustbepresentedwhenthe
instrumentistakentotheserviceagency.
3.Alwayshaveservicedonebya
Mclntoshauthorizedserviceagency.If
theinstrumentismodifiedordamaged
asa resultofunauthorizedrepair,the
SERVICECONTRACTwillbecancelled.
Damagebyimproperuseormishandl-
ingisnotcoveredbytheSERVICE
CONTRACT.
4.TheSERVICECONTRACTisissuedto
youastheoriginalpurchaser.Topro-
tectyoufrommisrepresentation,this
contractcannotbetransferredtoa se-
condowner.
5.ToreceivetheSERVICECONTRACT,
yourpurchasemustbemadefroma
Mclntoshfranchiseddealer.
6.Yourcompletelyfilledinapplicationfor
theSERVICECONTRACTmustbepost-
markedwithin30daysofthedateof
purchaseoftheinstrument.
7.ToreceivetheSERVICECONTRACT,all
informationontheapplicationmustbe
filledin.TheSERVICECONTRACTwill
beissuedwhenthecompletelyfilledin
applicationisreceivedbyMclntosh
LaboratoryIncorporatedinBinghamton,
NewYork.
8.UnitsinoperationoutsidetheUnited
StatesandCanadaarenotcoveredby
theMclntoshSERVICECONTRACT,re-
gardlessoftheplaceofpurchase.Nor
areunitsacquiredoutsidetheU.S.A.
andCanada,thepurchasersofwhich
shouldconsultwiththeirdealerto
ascertainwhat,ifany,servicecontract
orwarrantymaybeavailablelocally.
Copyright1985© byMclntoshLaboratoryInc.
2
MclNTOSHTHREEYEARSERVICECONTRACT

Introduction
WhytheC 30costsmorebutitsVALUETRIPLES
otherpreamplifiers.
TheMclntoshC 30isa superbquality,highperfor-
mancestereopreamplifier.Itsdesignhasbeen
governedbyinsistenceongreatflexibility,versatili-
tyandhighperformancewithlonglife.
Thisoutstandingpreamplifierwillserveyoubest
whenyouunderstanditsfunctionsandwhatitis
designedtodo.Sometimeinvestedwiththis
manualwillbevaluableinobtainingthemostfrom
yourC 30.
TheC 30providesmanyfeaturesforyourlistening
enjoyment.Theyinclude:
1.Highlevelinputstoaccommodatethetraditional
aswellasallthelatestaudiosourcessuchascom-
pactdiscplayersandthehighqualityaudiofrom
videorecordersandlaservideodiscplayers.
2.A speciallydesignedlownoiseswitching
systemoperatestheinputs,themodecircuitsand
thetapemonitorcircuit.Thissystemusesa pairof
cascadedfieldeffecttransistors(FET).Theinput
connectingleadsarenowveryshort,onetwentieth
(1/20}oftheirpreviouslength.Theadvantagesofthis
arrangementincludes,sourcetosourceisolation,
lowerdistortion,andfreedomfromhum,noiseand
highpowerTVandradarsignals.
3.Anyoneofseveninputsourcescanbeselected
usingelectronicswitching.Theseveninputsources
areturntable,tuner,compactdiscplayer,laservideo
discplayer,televisionaudio,videotaperecorderand
oneauxiliary.
4.Electronictapemonitorswitchesfortwotape
recordersalloweithertaperecordertobeheardfrom
themainoutput.
5.A fivebandprogramequalizerpermitsthead-
justmentandimprovementoftheloudnesscontrast
ofthefivemostimportantfrequencyranges.
Musicalbalanceofsourcematerialcanbeadjusted
tocompensateforroomrecordingdifferencesor
listenerpreferences.
6.A precisionmainoutputvolumecontroliselec-
tronicallytrimmedduringmanufacturetomaintain
channelbalanceaccuracytoa fractionofa decibel
(dB).Thishighorderofaccuracyassurescontinuing
programbalanceas thelisteningvolumeis changed.
7.A precisionheadphone-lineoutputvolumecon-
trolallowsheadphone-linevolumetobeadjustedin-
dependentlyofthemainvolume.Theconstruction
andperformanceofthiscontrolisidenticaltothe
mainvolumecontrol.
8.Anactivecircuitloudnesscontroliselectrically
independentofthevolumecontrol.Closeconformi-
tytotheFletcher-Munsonequalloudnesscurves
canbeattainedregardlessofthemainvolumecon-
trolposition.
9.A bandpassfilterswitchreduceshighfrequen-
cynoiseandlowfrequencyrumbleata 12dBperoc-
taverolloffrate.
10.Frontpaneltaperecorderjacksallowsimple
plug-inofanadditionaltaperecorderwithout
disconnectingyourregularsystem.Thismakes
playbackfromorcopyingtoa portablerecordervery
convenient.
11.AnautomaticACpowercontrolcircuitcan
convenientlyturnofftheentirestereosystemwhen
theturntableturnsoff.
12.A built-inheadphoneamplifier,withtwofront
paneljacks,powerstwopairsofdynamichead-
phones.
13.Twospeakeroutputpushbuttonscontrolthe
operationoftwosetsofloudspeakers(whenused
withtheoptionalSCR-2speakercontrolrelay)ortwo
setsofpoweramplifiersconnectedtotherearpanel
1or2 outputjacks.
14.Electronicallyregulatedpowersuppliesmain-
tainstableoperationevenduringperiodsoflowor
changinglinevoltage.
15.Rearpanelswitchingsignalprocessingjacks
forbothtapeoutandmainout.A noisereduction
unitorothersignalprocessingdevicecanbecon-
nectedtoeachsection.
3

Installation
Astudyinconvenience,simplicityandsecurity.
ThePANLOCsystemofinstallingequipmentcon-
venientlyandsecurely,isa productofMclntosh
research.BydepressingthetwoPANLOCbuttons
onthefrontpanel,theinstrumentcanbelocked
firmlyinplaceoritcanbeunlockedsothatthe
chassiscanslideforward,givingyoueasyaccessto
thetopandrearpanels.
Thetrouble-freelifeofanelectronicinstrumentis
greatlyextendedbyprovidingsufficientventilation
topreventthebuild-upofhighinternaltemperatures
thatcausedeteriorationofcomponentparts.You
shouldallowenoughclearancesothatcoolaircan
enteratthebottomofthecabinetandbevented
fromthetop.Withadequateventilationtheinstru-
mentcanbemountedinanyposition.Therecom-
mendedminimumspaceforinstallationis15inches
(38.1cm)deep,17inches(43.2cm)wide,and6 in-
ches(15.2cm)high.
Toinstalltheinstrumentina Mclntoshcabinet,
followtheinstructionsthatareenclosedwiththe
cabinet.Foranyothertypeofinstallationfollow
theseinstructions:
1.UnpackfromCarton
OpenthecartonandremovethePANLOCbrackets,
hardwarepackage,andmountingtemplate.Remove
theunitfromitsplasticbagandplaceitupside
downontheshippingpallet,thenunscrewthefour
plasticfeetfromthebottomofthechassis.
2.MarktheCabinetPanel.
Placethemountingtemplateinthepositiononthe
cabinetpanelwheretheinstrumentistobeinstall-
ed,andtapeitinplace.Thebrokenlinesthatrepre-
senttheoutlineoftherectangularcutoutalsorepre-
senttheoutsidedimensionsofthechassis.Make
suretheselinesclearshelves,partitions,orany
equipment.Withthetemplateinplace,firstmarkthe
sixA andB holesandthefoursmallholesthat
locatethecornersofthecutout.Then,jointhefour
cornermarkingswithpencillines,usingtheedgeof
thetemplateasa straightedge.
3.DrillHoles
Usea drillwitha 3/16inch(5mm)bitheldperpen-
diculartothepanelanddrillthesixA andB holes.
4

Then,usinga drillbitslightlylargerthanthetipof
yoursawblade,drilloneholeateachoftwo
diagonallyoppositecorners.Theholesshouldbare-
lytouchtheinsideedgeofthepenciledoutline.
Beforetakingthenextstep,makesurethatthesixA
andB holeshavebeendrilled.
4.SawthePanelCutout
Sawcarefullyontheinsideofthepenciledlines.
Firstmakethetwolongcutsandthenthetwoshort
cuts.Aftertherectangularopeninghasbeencutout,
usea filetosquarethecornersandsmoothanyir-
regularitiesinthecutedges.
5.InstalltheMountingStrips
Inthehardwarepackageyouwillfindtwomounting
strips,andtwosetsofmachinescrews.Forpanels
thatarelessthan1/2inch(12.7mrn)thick,usethe
3/4inch(19.1mm)screws;forpanelsthataremore
than1/2inch(12.7mm)thick,usethe1-1/4inch(31.8
mm)screws.
Startingattheright-handsideofthepanel,insert
ascrewoftheproperlengthintothecenterholein
thepanel,markedB onthetemplate.Onthebackof
thepanel,aligna mountingstripwiththeholesin
thepanelandtightenthescrewuntilthescrewhead
ispulledintothewood.
Repeatthisproceduretoattachthemounting
striptotheleftsideofthepanel.
6.AttachthePANLOCBrackets
UsingtwoscrewsoftheproperlengthintheA holes
oneachside,attachthePANLOCbracketstothe
cabinetpanel;theshortflangeismountedagainst
thefront(face)ofthecabinetpanel.Thescrews
passthroughthePANLOCbracketflange,the
cabinetpanel,andthenthroughthemountingstrips
previouslymounted.
7.installtheInstrument
GuidetheACpowercordthroughthepanelopening
tothebackofthecabinet;then,slidetheinstrument
intotheopeningcarefullysothattherailsonthe
bottomofeachsideofthechassisengagethe
tracksonthemountingbrackets.Continuetoslide
theinstrumentintothecabinetuntilitisstoppedby
theintermediatepositionlatches.Pressthelatches
inward,thispermitstheinstrumenttoslideintothe
cabinetuntilitsfrontpanelisflushwiththecabinet
panel.DepressthePANLOCbuttonsatthelowerleft
andrightcornersoftheinstrumentpaneltolockthe
unitfirmlyinthecabinet.DepressingthePANLOC
buttonsagainwillunlocktheinstrumentsothatit
canslideoutwardtotheintermediateposition;if
youpressinwardontheintermediatepositionlat-
chesthenyoucanremovetheinstrumentfromthe
cabinet.
5

HowtoConnect
Rearpanelinputjacksareprovidedfora stereo
turntable,PH;a stereotuner,TUNER;a compact
discplayer,CD;a laservideodiscplayer,LASER;a
TVreceiver,TV;a videocassetterecorder,VCR;an
auxiliaryhighlevelsource,AUX,andtwostereotape
recorders,TAPE1 andTAPE2.
Rearpaneloutputjacksareprovidedtofeedtwo
taperecorders,TAPE1 andTAPE2;three2.5volt
mainoutputs,MAIN,OUTPUT1,OUTPUT2;anda
line(headphonecircuit)output,LINE.Twosetsof
jacks,EXTERNALPROCESSORS:(onesetforMAIN
andonesetforTAPE,)areprovidedtoconnectnoise
reductionorothersignalprocessingunitstothe
mainandtaperecordcircuits.
HOWTOCONNECTA TURNTABLE:
Connectthecablefromtheleftchannelofthe
turntabletotheleftPHjack.
Connectthecablefromtherightchannelofthe
turntabletotherightPHjack.TheC 30uses
automaticshortingjacksforthephonoinputs.Ifthe
inputsarenotconnected,shortingplugsarenot
needed.
HOWTOCONNECTA STEREOTUNER:
Connectthecablefromthetunerleftchannelout-
puttotheleftTUNERINPUTjack.
Connectthecablefromthetunerrightchannel
outputtotherightTUNERINPUTjack.
HOWTOCONNECTA COMPACTDISCPLAYER:
ConnectthecablefromtheCDplayerleftchannel
outputtotheleftCDINPUTjack.
ConnectthecablefromtheCDplayerrightchan-
neloutputtotherightCDINPUTjack.
HOWTOCONNECTA LASERVIDEODISCPLAYER:
Connectthecablefromthelaservideodiscplayer
leftchannelaudiooutputtotheleftLASERINPUT
jack.
Connectthecablefromthelaservideodiscplayer
rightchannelaudiooutputtotherightLASERINPUT
jack.
HOWTOCONNECTA TVMONITOR:
ConnectthecablefromtheleftchannelTVaudio
outputtotheleftchannelTVINPUTjack.
ConnectthecablefromtherightchannelTVaudio
outputtotherightchannelTVINPUTjack.
HOWTOCONNECTA VCR:
Connectthecablefromtheleftchannelvideo
cassetterecorderaudiooutputtotheleftVCRIN-
PUTjack.
Connectthecablefromtherightchannelvideo
cassetterecorderaudiooutputtotherightVCRIN-
PUTjack.
HOWTOCONNECTTAPERECORDERS
TORECORD:
Connecta cablefromtheC 30leftTAPE1 OUT-
PUTjacktothelefthighlevelinputofa tape
recorder.Connecta cablefromtheC 30rightTAPE1
OUTPUTjacktotherighthighlevelinputofa tape
recorder.
Connecta secondtaperecorderinthesameman-
nertotheTAPE2 OUTPUTjacks.
TOPLAYBACKORMONITORTAPE:
Connecta cablefroma taperecorderleftchannel
outputtotheC 30leftTAPE1 INPUTjack.Connecta
cablefroma taperecorderrightchannelOUTPUTto
theC 30rightTAPE1 INPUTjack.
Connecta secondtaperecorderinthesameman-
nertotheC 30TAPE2 INPUTjacks.
6
TAPE2 inputandoutputconnectionsarealso
availableattheTAPE2 IN-OUTjacksonthefront
panel.Whena plugisinsertedinthefrontpanel
TAPEINjack,thecircuitstotherearpanelTAPE2
INPUTSwillbedisconnected.Insertinga pluginthe
frontpanelTAPEOUTjackdoesnotdisconnectthe
rearpanelTAPE2 OUTPUT.Thus,itispossibleto
recordfromthefrontpanelTAPEOUTjackandthe
rearpanelTAPE2 OUTPUTjackatthesametime.
However,itisnotpossibletolisten(ormonitor)from
boththefrontandrearTAPE2 INPUTjacksatthe
sametime.Metalshielded1/4"stereophoneplugs
maybeused.Connectionsaretip:leftsignal,ring;
rightsignal,andsleeve:commonground.
HOWTOCONNECTAUX:
Connecttheleftchannelcablefromanyhighlevel
source(tuner,TVset,recorder,etc.)totheleftAUX
INPUTjack.Connecttherightchannelcabletothe
rightAUXINPUTjack.
FRONTPANELTAPERECORDERJACKS:

TAPE
RECORDER2
VIDEOCASSETTE
RECORDER
TV FMANTENNA
TUNER
TAPERECORDER1
ACPOWER
OTHERACSWITCHED
OUTLETSFORTV,TAPE
RECORDERS,VCR,AND
TUNER
LASERVIDEODISC
PLAYER
ACPOWER
CDPLAYER
ACPOWERTOTURNTABLE
TURNTABLE
CONNECTIONSFORTURNTABLEANDHIGHLEVELPROGRAMSOURCES
7

HOWTOCONNECT
EXTERNALSIGNALPROCESSORS:
TherearetwosetsofEXTERNALPROCESSOR
jacks.Onesetisforthemainlisteningcircuitsand
theothersetisforthetaperecordcircuits.These
jacksareusedtoconnecttoandfroma noisereduc-
tionunitortoandfromanyothersignal processing
device.
Besuretomatchlefttoleftandrighttorightchan-
nelswhenconnectingexternalprocessors.
WhenconnectionsaremadetoanEXTERNAL
PROCESSOR,thesignalpathisautomatically
brokenbytheC 30switchingjacks.TheSIGNAL
PROCESSORMUSTBETURNEDONFORTHEPRO-
GRAMTOPASSTHROUGHTHEPREAMPLIFIER
CIRCUITS,
HOWTOCONNECTTOPOWERAMPLIFIERS:
Connecta cablefromtheleftC 30MAINOUTPUT
jacktotheleftpoweramplifierINPUTjack.
Connecta cablefromtherightMAINOUTPUTjack
totherightpoweramplifierINPUTjack.
Twoadditionalstereopoweramplifiersmaybe
connectedinthesamefashiontotheOUTPUT1 and
OUTPUT2 jacks.Audiooutputsignalissuppliedto
thesejacksonlywhenthefrontpanelpushbutton
SPEAKER/OUTPUTNo.1 and/orNo.2 pushbuttons
arepressed.Thisarrangementisusefulforlarge
systemswhereseparateamplifiersand
loudspeakersareusedatremotelocations.
Additionalamplifierscanserveremoteareassuch
asselectedlivingareas,workshoporoutdoor
recreationalfacilities.Otherdevicescanbecontroll-
edsuchasa rearchannelreverberationunit.
SPEAKERCONTROLRELAY
(anoptionalaccessory)
TheSPEAKERCONTROLRELAY,orSCR,is
designedtoprovidebothspeakercontrolswitching
andhighpowerswitchedACoutlets.Tocontrol
loudspeakers,SPEAKERS1 and2 pushbuttonson
thefrontpanelmustbeused.Whenthisisdone,
OUTPUTjacks1 and2 ontheC 30arenormallynot
used.Theoperationofoutputjacksandspeaker
controlwillotherwiseinterferewitheachother.
PlugthecablefromtheSCRintotheC 30back
panelSPEAKERCONTROLRELAYreceptacle.Con-
nectthepoweramplifieroutputtotheFROM
POWERAMPLIFIERterminalsontheSCR.Observe
correctchannelidentificationaswellascorrect
polarity.TheMAINspeakers(controlledby
SPEAKER1 pushbutton)areconnectedattheTO
MAINSPEAKERterminals.TheREMOTEspeakers
(controlledbySPEAKER2 pushbutton)arecon-
nectedattheTOREMOTESPEAKERSterminals.
Again,observecorrectchannelidentificationand
polarity.
SPEAKER1 AND2 USINGTHESCR:
Whenpushbutton1 isINandpushbutton2 isOUT,
themainspeakerswillbeconnectedtothepower
amplifierviatherelaysintheSCR.Whenpushbutton
1isOUTandpushbutton2 isIN,theremote
speakerswillbeconnectedinstead.Whenboth
pushbuttons1 and2 areIN,bothsetsofspeakers
willbeconnected.
CAUTION:Whenbothsetsofspeakersarecon-
nectedatthesametime,theircombinedparallelim-
pedancemustnotbetoolowtoproperlymatchthe
poweramplifieroutputimpedance.Forexample:if
bothsetsofspeakersare8 ohms,connectionsto
thepoweramplifiermustbetothe4 ohmtap.Ifthe
amplifierdoesnothavedifferentimpedancetaps,it
mustbe ableto deliverpowerto a4 ohmloadas well
asan8 ohmload.
TheSCRalsohastwoACpoweroutletsthatpro-
videadditionalcapacityof2400wattsswitchedby
theC 30.UsetheseoutletstosupplyACpowerto
amplifiersorothercomponentswheneverthetotal
loadtobeswitchedbytheC30exceedstheratingof
1200watts.PlugtheSCRheavylinecorddirectlyin-
toa walloutlet.WhentheC 30isturnedon,power
fromtheC 30willenergizea relayintheSCRwhich
connectsthetwoSCRACoutletsdirectlytothewall
outlet.DonotplugtheC 30powercordintotheSCR
asthepreamplifiercannotfunctionwhensocon-
nected.
HOWTOCONNECTACPOWER:
PlugthepreamplifierACpowercordintoa 120
volt60Hzwalloutlet.A polarizedattachmentplugis
used.Becertainthattheplugbladescanbefullyin-
sertedintheoutlettopreventbladeexposure.See
thecautionnoticeonpage1.
ThreetypesofACpoweroutletsareprovidedon
thebackpaneloftheC 30.Sixareblack,oneisred
andoneisgreen.
Theblackoutletsareswitchedonandoffwhen
theC 30isturnedonandoff.Theseareintendedfor
poweramplifiers,CDplayers,equalizersandother
accessoriestotalingupto1200wattscapacity.
Theredoutletisonatalltimes.Forexample,a
VCRcanbepluggedintothisoutletforrecordinga
TVprogramwhenthemainsystemisnotturnedon.
ThegreenACpoweroutletisonatalltimesandis
foruseonlywitha turntable.Donotusethisoutlet
foranyotherpurpose.Theturntablecanbeusedas
apowerswitchasdescribedinthefollowingsec-
tion.
8

AGROUNDpostisprovidedtoconnectthe
groundsfromrecordchangers,tapedecks,etc.To
preventhumpick-up,theleftandrightprogram
cablesandthegroundwirefromthatsourceshould
bewoundortwistedtogether.Makesuretheground
wiredoesnotmakeanyconnectiontotheshieldsof
theleftandrightprogramcablesastheyrunbe-
tweenthesourceandtheinputofthepreamplifier.
FUSE:
A1.0AMPfuseprotectstheC 30turntablecurrent
sensingcircuitsandthegreenACturntableoutlet.
Thefusedoesnotprotectequipmentconnectedto
theblackACoutlets.Thisfusemustbereplaced
withthesametypeandrating.A 1.0AMPfastacting
orSLOBLOfusemaybeused.
9
HOWTOCONNECTPROGRAMGROUNDS:
HOWTOUSETHETURNTABLEASA POWER
SWITCH:
IfaturntableisusedwiththeC 30,itcanbeused
toturnyourentiresystemonandoff.Theturntable
mustbepluggedintothegreenACoutletattherear
oftheC 30.TheAUTO/MANUALswitchalsoatthe
rearmustbeintheAUTOposition.Whenyouswitch
onthepowertotheturntable,a specialsensorcir-
cuitwilldetectthecurrentdrainoftheturntableand
willturnontheC 30thesamewaytheredPOWER
pushbuttondoes.Theredpushbuttonmustbeinthe
OFForoutpositiontodothis.Readthesectionon
AUTO-ONSENSITIVITYonpage(14)beforeusing
thisfeature.

10
REMOTEAREA2
(CONTROLLEDBY
SPEAKER2
PUSHBUTTON)
REMOTEAREA1
(CONTROLLEDBY
SPEAKER1
PUSHBUTTON)
POWER
AMPLIFIERS
NOISEREDUCTIONPROCESSORS
TAPE MAIN
CUSTOM
ENVIRONMENTAL
EQUALIZER
(FORMAINSPEAKERS)
POWER
AMPLIFIER
MAINSPEAKERS
CONNECTIONSFOR
POWERAMPLIFIERS
ANDLOUDSPEAKERS
USINGMAINSPEAKERSAND
ENVIRONMENTALEQUALIZER.
ALSOSHOWNFORREMOTE
SPEAKERSUSINGSEPARATE
POWERAMPLIFIERSAND
CONNECTIONSFOREXTER-
NALNOISEREDUCTION
SIGNALPROCESSORS.

CONNECTIONSFOR
POWERAMPLIFIERS
ANDLOUDSPEAKERS
USINGSPEAKER
CONTROLRELAY(SCR)
11
MAINSPEAKERS
(CONTROLLEDBY
SPEAKER1 PUSHBUTTON)
REMOTE
SPEAKERS
(CONTROLLEDBY
SPEAKER2
PUSHBUTTON)
TOACLINE
POWER
AMPLIFIER

TheFrontPanelControls
andHowtoUseThem
INPUTSELECTOR:
TheINPUTselectorswitchislocatedattheupper
leftonthefrontpanel.Thisswitchselectstheinput
desiredfornormallistening.Theinputprogram
selectedwillalsoappearattheTAPEOUTPUTjacks.
MODESELECTOR:
TheMODESELECTORallowsyoutoidentifyeach
stereochannel,createmonophonicprogram
material,anddirectprogrammaterialtoonechannel
ortheother.Thisswitchcontrolsthemainoutputs
only,andnotthetapeoutputs.
Theswitchcontrolstheprograminsevenways.
LTOL&R:Connectstheleftinputtobothleftand
rightoutputcircuits.
RTOL&R:Connectstherightinputtobothleftand
rightoutputcircuits.
STEREOREV:Connectstheleftinputtotheright
outputcircuitandtherightinputtotheleftoutput
circuit.
STEREO:Connectstheleftinputto theleftoutput
circuitandtherightinputtotherightoutputcircuit.
UsethisSTEREOpositionfornormallistening.
MONO(L+R):Addstheleftandrightinputs
togethertoproducea monophonicprogramandcon-
nectstobothoutputcircuits.
L+ R TOL:Connectstheleftplusrightprogramto
theleftoutputcircuitonly.
L+ R TOR:Connectstheleftplusrightprogramto
therightoutputcircuitonly.
EQUALIZERFREQUENCYCONTROLS:
EachoffiveEQUALIZERFREQUENCYcontrols
raisesorlowerstheamplitudeofa bandoffrequen-
ciescenteredonthefrequencymarkedabovethe
control.Bothleftandrightchannelsareaffected.
Thecenter,orflatpositionofthecontrolhasa de-
tentforeasyreference.Atdetent,theequalizerband
isremovedfromthepreampcircuit.
UsetheEQUALIZERFREQUENCYcontrolsto
modifythesoundandbalanceofprogrammaterial.
Herearesomesuggestionsfromwhichtostart.
ADJUSTMENTTOEQUALIZERCORRECTION
Makea deepbass
louderRaise30
Makeallbass
louder
Reinforcevoices
Humonprogram
Brightenviolins
andtrumpets
Raise30and150
Lower150andraise500
Reduce30and150
Raise1500
EmphasizecymbalsRaise10K
HEADPHONEVOLUME:
Thiscontrolallowsindependentadjustmentof
theheadphonevolume(aswellasLINEOUTPUT)
withoutaffectingthemainlistenvolume.Themain
volumecontroldoesaffectheadphonevolumeand
mustbeturneduptoa reasonablelevelpriortoad-
justingtheheadphonevolumecontrol.
VOLUMECONTROL:
TheVOLUMEcontrolisa precisionstepcontrol
12

manufacturedforMclntoshLaboratory.Ithas32steps
witha 70dBrange,plusvolumeoff.Leftandright
channeltrackingarewithina fractionof1dB.Thisex-
tremeaccuracyisobtainedthroughspecialelec-
tronicallycontrolledresistanceelementtrimming.
BALANCEANDLOUDNESS:
TheBALANCEandLOUDNESScontrolsarecon-
centric.TheBALANCEcontrol(largeouterknob)ad-
juststhevolumeofthechannelsrelativetoeach
other.
L...turningthecontroltotheleftaccentstheleft
channelbyreducingtherightchanneloutput.
R...turningthecontroltotherightaccentsthe
rightchannelbyreducingtheleftchanneloutput.
LOUDNESS:
TheLOUDNESScontrol(smallcenterknob)pro-
videsa frequencyresponsecontourwhichcompen-
satesforthehearingcharacteristicofthehumanear
atlowerlisteninglevels.Thiscontourisaccurately
modeledafterthefamilyof"equalloudness"curves
identifiedbyFletcherandMunson.Atthefully
counterclockwisedetentedFLATposition,the
loudnesscontouriselectricallyflat.Asthecontrol
isturnedclockwise,bothbassandtreblefrequen-
ciesincreaseinthecorrectproportion.Thecontour
isnotaffectedbydifferentsettingsoftheVOLUME
control.AftersettingtheVOLUMEcontrolforthe
desiredlisteninglevel,adjusttheloudnesscontrol
forthepreferredcompensation.
TAPEPUSHBUTTONS:
IMPORTANT:WhentheC 30isoperatedwith
eitherMONITORpushbuttonattheINposition,the
programheardwillbethatfromthetaperecorders
only.Signalfromanyothersourcewillnotbeheard
fromtheloudspeakers.Tohearanyothersource,
makesuretheMONITORpushbuttonsareOUT.
TheMONITORswitchesaremechanicallyin-
terlockedtopreventsimultaneousmonitoringfrom
twotaperecorders.Ifonebuttonisattheinposi-
tion,itmustbepushedagaintoreleaseittotheout
positionbeforetheotherbuttoncanbepushed.
TheC 30isdesignedsothatitmaybeusedwith
twotaperecorders.Thefourpushbuttonstotheleft,
controlthesignaloutputoftheserecorders.They
permitrecordingstobemonitoredastheyarebeing
recorded,orcopyingoftapesfromonerecorderto
anotherwhilelisteningtoa separateprogramorthe
playbackofeitherrecorder.
MONITORTAPE1 pushbuttonout:Theprogram
sourceasselectedbytheINPUTSELECTORisfed
tothepoweramplifiersandheardthroughtheloud-
speakers;pushbuttonin:Signalfroma taperecorder
pluggedintoINPUTTAPE1 isfedtothepower
amplifiersandheardthroughtheloudspeakers.
MONITORTAPE2 pushbutton:Functionssimilar-
lytomonitorTape1.Italsocontrolstheprogram
froma taperecorderpluggedintothefrontpanel
TAPEINandOUTjacks.Whena taperecorderis
pluggedintothefrontjackstheTAPE2 INjackson
therearpanelareautomaticallydisconnected.The
TAPE2 outputsareconnectedatbothfrontandrear
jacks.
TAPECOPYT1 T2pushbuttonin:connectsthe
outputfromtaperecorder1 totheinputoftape
recorder2 withoutaffectingtheprogrambeing
heardfromthespeakers.Inthispositiona copyof
thetheprogramontaperecorder1 canbemadeon
taperecorder2.Tomonitortheoriginal,use
MONITORTAPE1 pushbuttonandtomonitorthe
copyuseMONITORTAPE2 pushbutton.Whenboth
MONITORpushbuttonsareout,youhearthepro-
gramfromtheInputSelector.
TAPECOPYT2T1pushbuttonin:connectsthe
outputfromtaperecorder2 totheinputoftape
recorder1 withoutaffectingtheprogrambeing
heardfromthespeakers.Inthispositiona copyof
thetapeprogramonrecorder2 canbemadeon
recorder1.TomonitortheoriginaluseMONITOR
TAPE2 pushbuttonandtomonitorthecopyuse
MONITORTAPE1 pushbutton.
SPEAKEROUTPUT1 AND2:
TheSPEAKER/OUTPUT1 and2 pushbuttonscan
beusedtocontroleithertheOUTPUTjacks1 and2,
orthemainandremotespeakerswhentheoptional
SPEAKERCONTROLRELAY(SCR)isconnected.
TheSPEAKER/OUTPUTpushbuttonsshouldnotbe
usedtocontrolconnectionstothe1 and2 jacksand
anSCRforspeakerswitchingatthesametime.The
operationoftheoutputjacksandthespeakercon-
trolwillinterferewitheachother.
POWERON:
ThePOWERONpushbuttonsharesACpower
control,througha currentdetectingswitchcircuit,
withtheACpowerswitchona turntable.Ontherear
paneltheTURNTABLEAUTO/MANUALswitch
selectsthemodeofoperation.Whentheswitchisin
theAUTOpositionanda turntableispluggedinto
thegreenACpoweroutlet,theACpowertothe
preampandtotheblackACpoweroutletscanbe
controlledbytheturntableon/offswitch.Whenthe
turntablepowerswitchisturnedon,thepreamplifier
andtheSWITCHEDblackACpoweroutletsareturn-
edon.Thesystemwillremainonuntiltheturntable
isturnedoff.ThePOWERONpushbuttonswitch
parallelstheautomaticturntablepowercontrol
feature.ThePOWERONpushbuttonisusedtoturn
poweronandoffwhentheturntableisnotused.The
POWERONpushbuttonmustbeoutoroffforthe
turntabletocontroltheACpower.
IntheMANUALpositiononlythePOWERON
pushbuttonwillturnpoweronorofftothe
preamplifierandtheblackACpoweroutlets.
13

FRONTPANELPUSHBUTTON
INDICATORLAMPS:
InallcasesofuseofC 30frontpanelpushbut-
tons,theINorONpositionisindicatedbya redlamp
abovetheswitch.
TAPERECORDERFRONTPANELCONNECTION:
Inputandoutputfacilitiesareavailableatthe
TAPEIN-OUTjacksonthefrontpanel.Thesefront
paneljacksmakeconnectionswithouthavingto
haveaccesstotherearpanel.Whenusingthefront
paneljacks,therearpanelTAPE2 INPUTjacksare
disconnectedautomatically.A metalshielded1/4
inchstereophoneplugisusedforbestshielding.
Connectionsfollowtheindustrystandardsandare
tip:leftsignal,ring:rightsignal,andsleeve:com-
monground.
HEADPHONES:
ThefrontpanelHEADPHONEjackhasbeen
designedtofeedlowimpedancedynamichead-
phones.Electrostaticheadphonesgenerallyrequire
higherpowerthandynamicheadphonesandare
connectedtotheoutputterminalsonthepower
amplifier.
PlugheadphonesintoeitherfrontpanelHEAD-
PHONEjack.Adjustthefrontpanelheadphone
VOLUMEcontrolforcomfortableheadphonelisten-
ing.
Themainvolumecontrolalsoaffectsheadphone
volumeandmustbeturneduptoa reasonablelevel
priortoadjustingtheheadphonevolumecontrol.
AnamplifierintheC 30providesthepowerthat
feedsboththeHEADPHONEjacksonthefront
panelandtheLINEOUTPUTjacksontherearpanel.
PANLOC:
MclntoshdevelopedPANLOCmountingbrings
professionalinstallationtechniquetohomestereo
systems.WhenthePANLOCbracketsareinstalled
inthecabinet,theunitslideseasilyinplacetothe
intermediateposition.Latchesonthesidesofthe
unitsnapintopositionatthispoint.Bypressing
thesespringlatchesinward,theyreleaseandallow
theunittoslidecompletelyintothecabinet.Then
depressthefrontpanelPANLOCbuttonstotheirIN
positiontolocktheunitintothecabinet.Depressing
thePANLOCbuttonsagaincausesthemtorelease
totheirOUTposition,allowingtheunittoberemov-
edtotheintermediateposition.Pressthein-
termediatelatchesagaintoallowtheunittobe
removedfromthecabinet.
14

RearPanelControls
AUTOMANUALSWITCH:
IntheMANUALposition,thegreenACoutletsup-
plysnormallinevoltageatalltimesandtheturn-
tableoperationhasnoeffectontheC 30operation.
IntheAUTOposition,whentheturntableturnson
andoff,itwillalsocausetheC 30andtheentire
systemtoturnonandoff.
AUTO-ONSENSITIVITY:
TheAUTO-ONSENSITIVITYcontrolislocatedon
therightrearofthebackpanel.Fornormalopera-
tionwithmostturntables,thecontrolcanbeleftat
mid-position.Someturntables,however,haveelec-
troniccircuitsthatdrawcurrentwhethertheyare
turned"off"ornot.TheC 30AUTO-ONSENSITIVITY
controlcanbeusedto"finetune"forthesmallerdif-
ferencebetweenonand"off"currents.
IfyourturntabledoesnotcontroltheAUTO-ON
featureoftheC 30correctly,useoneofthefollow-
ingprocedures:
1.Switchontheturntable.IftheC 30doesnotgo
on,orgoesonbutdoesnotstayon,rotatetheAUTO-
ONSENSITIVITYcontrolclockwisetowardsMAX
untiltheC 30goesonandstayson.Thencheckfor
properoperation.
2.Switchofftheturntable.IftheC 30doesnotgo
off,rotatetheAUTO-ONSENSITIVITYcontrol
counterclockwisetowardsMINuntilitdoesgooff.
Checkforproperoperation.
Ifthisdoesn'tcorrecttheproblem,yourturntable
probablyhaselectroniccircuitsthatdrawthesame
ornearlythesamecurrentwhetheronoroff.AUTO-
ONcontrolisnotpossiblewhenusingthisturntable.
ThegreenACoutletcanstillbeusedbutthe
AUTO/MANUALswitchmustbesetintheMANUAL
position.TheredPOWERpushbuttonmustbeused
instead.
15

PerformanceLimitsandRatings
PERFORMANCELIMITS
Performancelimitsarethemaximumdeviation
fromperfectionpermittedfora Mclntoshinstru-
ment.Wepromiseyouthatwhenyoupurchasea
newC 30froma Mclntoshfranchiseddealer,itwill
becapableoforcanbemadecapableofperfor-
manceatorexceedingtheselimitsoryoucanreturn
theunitandgetyourmoneyback.Mclntoshisthe
onlymanufacturerthatmakesthisstatement.
FREQUENCYRESPONSE
+0, -0.5dB from20Hz to 20,000Hz
MAXIMUMVOLTAGEOUTPUT
MainandTapeOutput-10Vfrom20to
20,000Hz
Line/ HeadphoneOutput-9V(1.3Vwith8 ohm
headphones)from20to20,000Hz
TOTALHARMONICDISTORTION
.007%maximumfrom20to20,000Hzat2.5Vrated
output
SENSITIVITY
Phono-2mVfor2.5Vratedoutput(0.4mVIHF)
HighLevel-200mVfor2.5Vratedoutput
(40mVIHF)
SIGNALTONOISERATIO,A-WEIGHTED
Phono-90dBbelow10mVinput(84dBIHF)
HighLevel-100dBbelowratedoutput(86dBIHF)
MAXIMUMINPUTSIGNAL
Phono-100mV
HighLevel-10V
INPUTIMPEDANCE
Phono-47kohmsand65pFcapacitance
HighLevel-22kohms
VOLTAGEGAIN
PhonotoTape-40dB
PhonotoMain-62dB
PhonotoHeadphone/ Line-68dB
(51dBwith8 ohmheadphones)
HighLeveltoTape-0dB
HighLeveltoMain-22dB
HighLeveltoHeadphone/ Line-28dB
(11dBwith8 ohmheadphones)
EQUALIZATIONCONTROL
Variable12dBboostto12dBcutatcenterfreq-
uenciesof30,150,500,1500,10kHz
LF-HFFILTER
Flatorroll-offat12dBperoctavebelow50Hzand
above7,000Hz
GeneralInformation
SEMICONDUCTORCOMPLEMENT
28BipolarTransistors
66FieldEffectTransistors
15IntegratedCircuits
91Diodes
1SiliconControlledRectifier(SCR)
ACPOWEROUTLETS
1Turntablecurrent-sensing,green,100watts
6Switched,black,and1 unswitched,red,
1200wattstotal
POWERREQUIREMENTS
120volts,50/60Hz,25watts
MechanicalInformation
SIZE
Frontpanelmeasures16incheswide(40.6cm)by
5-7/16incheshigh(13.8cm).Depthofunitfrom
mountingsurfaceis13inches(33.0cm)including
PANLOCshelfandbackpanelconnectors.Knob
clearancerequiredis1-1/4inches(3.2cm)infront
ofthemountingpanel.
FINISH
Frontpanelisanodizedgoldandblackwith
specialgold/tealnomenclatureillumination.
Chassisisblack.
MOUNTING
ExclusiveMclntoshdevelopedprofessional
PANLOC
WEIGHT
18pounds(8.2kg)net,30pounds(13.6kg)inship-
pingcarton
16

PerformanceCharts
FREQUENCYRESPONSE
AUXINTOMAINOUT
LFANDHFFILTERS
10 100 1K
FREQUENCYINHERTZ
10K 100K
10K20K
LOUDNESSCONTROLRESPONSE
FORVARIOUSCONTROL
POSITIONS
FREQUENCYINHERTZ
EQUALIZERFREQUENCYRESPONSE
CONTROLSSETATMAXIMUM
ANDMINIMUM
20
10
EQUALIZERFREQUENCYRESPONSE
CONTROLSSETATMAXIMUM
ANDMINIMUM
-10
-20
20 1001K
FREQUENCYINHERTZ
10K20K
17
0
RESPONSE
INdB
RESPONSE
INdB
20 100 1K
0
5
10
15
20
-20
-16
-12
-8
-4
0
RESPONSE
INdB

20
RIAAEQUALIZATIONCURVE
20
100
1K
FREQUENCYINHERTZ
10K20K
HARMONICDISTORTION
AUXINTOMAINOUT
18
.05
.04
.03
.02
.01
0
2345679 1012
RMSOUTPUTVOLTS
HARMONICDISTORTION
IN
PERCENT
20
10
0
-10
-20
RESPONSE
INdB