McIntosh C38 User manual

C38
SYSTEM
CONTROL
CENTER

IMPORTANT
SAFETY
INSTRUCTIONS
THESE
INSTRUCTIONS
ARETOPROTECT
YOUANDTHE
MclNTOSH
INSTRUMENT.
BESURETO
FAMILIARIZE
YOURSELF
WITHTHEM
1.Readallinstructions- Readthesafetyandoperatinginstructionsbeforeoperatingtheinstrument.
2.RetainInstructions- Retainthesafetyandoperatinginstructionsforfuturereference.
3.Heedwarnings- Adheretowarningsandoperatinginstructions.
4.FollowInstructions- Followalloperatinganduseinstructions.
WARN ING:TO REDUCE RISK OF FIRE OR ELECTRICALSHOCK, DONOT EXPOSE THIS IN-
STRUMENTTORAINORMOISTURE.
5.PowerSources- Connectthepowersupplyonlytothetypedescribedintheoperatinginstructions
orasmarkedontheunit.
6.Power-CordProtection- Routepower-supplycordssothattheyarenotlikelytobewalkedonor
pinchedbyitemsplaceduponoragainstthem,payingparticularattentiontocordsatplugs,
conveniencereceptacles,andthepointwheretheyexitfromtheinstrument.
7.Ventilation- Locatetheinstrumentforproperventilation.Forexample,theinstrumentshouldnot
beplacedona bed,sofa,rug,orsimilarsurfacethatmayblockventilationopenings;or,placed
ina built-ininstallation,suchasa bookcaseorcabinet,thatmayimpedetheflowofairthrough
theventilationopenings.
8.Heat- Locatetheinstrumentawayfromheatsourcessuchasradiators,heatregisters,stoves,or
otherappliance(includingamplifiers)thatproduceheat.
9.WallorCabinetMounting- Mounttheinstrumentina wallorcabinetonlyasdescribedintheowner's
manual.
10.WaterandMoisture- Donotusetheinstrumentnearwater- forexample,neara bathtub,washbowl,
kitchensink,laundrytub,ina wetbasement,orneara swimmingpool,etc.
11.Cleaning- Cleantheinstrumentbydustingwitha drycloth.Cleanthepanelwitha clothmoistened
witha windowcleaner.
12.ObjectandLiquidEntry- Donotpermitobjectstofallandliquidstospillintotheinstrumentthrough
enclosureopenings.
13.NonusePeriods- UnplugthepowercordfromtheACpoweroutletwhenleftunusedfora longperiod
oftime.
14.DamageRequiringService- Servicemustbeperformedbyqualifiedservicepersonnelwhen:
A.Thepowersupplycordortheplughasbeendamaged;or
B.Objectshavefallen,orliquidhasbeenspilledintotheinstrument;or
C.Theinstrumenthasbeenexposedtorain;or
D.Theinstrumentdoesnotappeartooperatenormallyorexhibitsa markedchangeinperformance;
or
E.Theinstrumenthasbeendropped,ortheenclosuredamaged.
15.Servicing- Donotattempttoservicebeyondthatdescribedintheoperatinginstructions.Allother
serviceshouldbereferredtoqualifiedservicepersonnel.
16.GroundingorPolarization- Donotdefeattheinherentdesignfeaturesofthepolarizedplug.Non-
polarizedlinecordadaptorswilldefeatthesafetyprovidedbythepolarizedACplug.
17. CAUTION:TOPREVENTELECTRICALSHOCKDONOTUSETHIS(POLARIZED)PLUG
WITHANEXTENSIONCORD,RECEPTACLEOROTHEROUTLETUNLESSTHEBLADESCAN
BEFULLYINSERTEDTOPREVENTBLADEEXPOSURE.
ATTENTION:POURPREVENIR LES CHOCSELECTRIQUES PAS UTILISERCETTE
FICHEPOLARISEEAVECUNPROLONGATEUR,UNEPRISEDECOURANTOUUNEAUTRE
SORTIEDECOURANT,SAUFSILESLAMESPEUVENTETREINSEREESA FONDSANSEN
LAISSERAUCUNEPARTIEA DECOUVERT.
Thelightningflashwitharrowhead,withinanequilateraltriangle,isintendedtoalertthe
usertothepresenceofuninsulated"dangerousvoltage"withintheproduct'senclosure
thatmaybeofsufficientmagnitudetoconstitutea riskofelectricshocktopersons.
Copyright1992© by
McintoshLaboratoryInc.
CAUTION:TO PREVENT THE RISK OF ELECTRIC SHOCK,DONOT
REMOVECOVER(ORBACK).NOUSER-SERVICABLEPARTSINSIDE.
REFERSERVICINGTOQUALIFIEDPERSONNEL.
Theexclamationpointwithinanequilateraltriangleisintendedtoalerttheusertothe
presenceofimportantoperatingandmaintenance(servicing)instructionsintheliterature
accompanyingtheappliance.
WARNING:THISUNITISCAPABLEOFPRODUCINGHIGHSOUND
PRESSURELEVELS.CONTINUEDEXPOSURETOHIGHSOUND
PRESSURELEVELSCANCAUSEPERMANENTHEARINGIMPAIRMENT
ORLOSS.USERCAUTIONISADVISEDANDEARPROTECTIONIS
RECOMMENDEDWHENPLAYINGATHIGHVOLUMES.
2

YourdecisiontoownthispieceofMcintoshStereoEquipmentranksyouattheverytopamong
discriminatingmusiclisteners.Younowhave"TheBest".TheMcintoshdedicationto"Quality",is
assurancethatyouwillreceivethousandsofhoursofmusicalenjoymentfromthisunit.
Pleasetakea shorttimetoreadtheinformationinthismanual.Wewantyoutobeasfamiliaras
possiblewithallthefeaturesandfunctionsofyournewpieceofMcintosh.Thiswillensurethatyou
receivealltheperformancebenefitsthisinstrumentcanofferyou,andthatitwillbecomea highlyvalued
partofyourhomemusicsystem.
Theserialnumber,purchasedate,andMcintoshLaboratoryServiceContractnumberare
importanttoyouforpossibleinsuranceclaimorfutureservice.Recordthisinformationhere.
SERVICECONTRACT4
INTRODUCTION. 5
HOWTOINSTALLTHEC38. . .6
FRONTPANELCONTROLS,SWITCHESANDPUSHBUTTONS6,7,8
HR38HANDHELDREMOTECONTROLLER8,9
THEREARPANELANDHOWTOMAKECONNECTIONS9,10,11,12,13
SPECIFICATIONS14
PERFORMANCECHARTS..15
TECHNICALDESCRIPTION16,17
INSTALLATIONDIAGRAM:.18
3
THANK
YOU
TABLEOF
CONTENTS
PurchaseDate
ServiceContractNumber
SerialNumber
Uponapplication,McintoshLaboratoryprovidesa ServiceContracttotheoriginalpurchaser.
YourMcintoshAuthorizedServiceAgencycanexpediterepairswhenyouprovidetheSer-
viceContractwiththeinstrumentforrepair.

TAKEADVANTAGEOF3 YEARSOFCONTRACTSERVICE.. .
FILLINTHEAPPLICATIONNOW.
YourC38SystemControlCenterwillgiveyoumanyyearsofsatisfactoryperformance.Ifyou
haveanyquestions,pleasecontact,
McintoshLaboratoryInc.
2ChambersStreet
Binghamton,NewYork13903-2699
Phone:[phone]
AnapplicationforA THREEYEARSERVICECONTRACTisincludedwiththismanual.
Thetermsofthecontractare:
1.Iftheinstrumentcoveredbythiscontractbecomesdefective,Mcintoshwillprovideallparts,
materials,andlaborneededtoreturnthemeasuredperformanceoftheinstrumenttothe
originalperformancelimitsfreeofanycharge.Theservicecontractdoesnotcoverany
shippingcoststoandfromtheauthorizedserviceagencyorthefactory.
2.AnyMcintoshauthorizedserviceagencywillrepairallMcintoshinstrumentsatnormal
servicerates.Toreceivethefreeserviceunderthetermsoftheservicecontract,theser-
vicecontractcertificatemustaccompanytheinstrumentwhentakentotheserviceagency.
3.Alwayshaveservicedonebya Mcintoshauthorizedserviceagency.Ifthe instrument is
modified or damaged as a result of unauthorized repair the service contract will be cancell-
ed. Damagebyimproperuseormishandlingisnotcoveredbytheservicecontract.
4.Theservicecontractisissuedtoyouastheoriginalpurchaser.Toprotectyoufrom
misrepresentationthiscontractcannotbetransferredtoa secondowner.
5.UnitsinoperationoutsidetheUnitedStatesandCanadaarenotcoveredbytheMcintosh
FactoryServiceContract,irrespectiveoftheplaceofpurchase.Norareunitsacquired
outsidetheUSAandCanada,thepurchasersofwhichshouldconsultwiththeirdealer
toascertainwhat,ifany,servicecontractorwarrantymaybeavailablelocally.
MclNTOSH
THREEYEAR
SERVICE
CONTRACT
4

McintoshLaboratoryhasearneda worldwidereputationforitstechnicalcontributionsfor
improvedsoundreproduction.Mcintoshproductsincorporateanadvancedleveloftechnical
innovationsthathaveintegrityprovenbytime.TheMcintosh"Classic"designisalsorecogniz-
edasthemostoutstandingintheindustry.
Mcintoshproductsaredesignedtobemaximumuserfriendly,soanyonecanenjoyusing
them.AnotherMcintoshdesignpolicyistoprovideproductsthatareeasytomaintain.The
legendaryreliabilityofMcintoshproductsisa matterofrecordsince1949.
TheC38,RemoteControlled,SystemControlCenterisa perfectexampleofa simple,yet
elegantinstrumentwhichwillallowyoutoenjoyoutstandingmusicreproductiontogether
witha widerangeofconvenientoperatingfunctions.TheC38hasa built-incapabilityofcon-
trollingtwoseparatelisteningareas.TheLISTENsignalsaredefinedasAreaA whichisusually
themainareawhereallthesoundequipmentislocated.TheRECORDsignalsareavailable
ata pairofoutputsmarkedB,andcanbeusedfora remoteareawithitsowndedicated
poweramplifierandpairofspeakers.
Dataportsareprovidedforsevenaudioremotecontrolledaccessories.Thisfeatureallows
youtocontrola compatibleunitbytransmittingwithitshandheldremotecontrollerdirect
toa C38sensor.A dataportisalsoprovidedtocontroltheoptionalMcintoshMVS-3Video
Selectorforswitchingvideosignalsinadditiontoaudiosignals.Anotherdataportconnects
totheoptionalMcintoshHC-1HomeControllertoallowcontrolofaccessoriesorappliances.
TheconvenienceofC38remotecontroloperationisenhancedbyitscapabilityofdirectly
interfacingwiththeMcintoshCR10RemoteControlSystem.TheCR10canaddanadditional
fourremoteareasofcontrol.
Thereareeightpairsofhighlevelinputstoaccommodateallthetraditionalprogramsources
aswellasthemostrecentnewsources.A pairoflowlevelinputsisalsoprovidedthatwill
acceptsignalsfroma movingmagnetphonocartridgeina recordplayer.DigitalLogicin-
tegratedcircuitsdriveElectromagneticSwitchesonallinputsandoperatingfunctionsforthe
mostreliableanddistortionfreeswitchingavailable.
SeparateRECORDandLISTENcircuitsallowrecordingfromonesourcewhilelistening
toanother.A continuouslyvariableActiveLoudnessControlallowsloudnesscompensation
tobeselectedforanysettingofthevolumecontrol.TheLoudnessControlcircuitelements
areremovedfromthecircuitpathwhenthecontrolisintheflatorfullycounterclockwise
position.
BassandTrebletonecontrolsprovide12dBofboostorcut.Atthecenter"FlatResponse"
ordetentpositionofthetonecontrols,alltonecontrolcircuitelementsareremovedfrom
thesignalpath.
TwoSignalProcessorloopsareprovided.OneisforListensignalsandoneisforRecord
signals.Powersupplyvoltageregulatorcircuitsmaintainstableoperationeventhoughthe
ACpowerlinemayvary.Doubleshieldingofthepowertransformercompletelyisolatesitfrom
theaudiocircuits.Thiseliminatestheneedfora clumsyoutboardpowertransformerused
bysomelesssophisticateddesigns.
Frontpanelpushbuttonscontroltwoswitchedoutputsaswellastwopairsofspeakers
whenanoptionalSCR3switchingrelayisadded.
TheMcintoshC38"ClassicGlass"frontpanelhasallcontrol,switchandpushbutton
nomenclatureilluminated.
5
INTRODUCTION

TheC38canbeplaceduprightona tableorshelf,standingonitsownplasticfeet.Itcan
alsobeinstalledinanoptionalMcintoshL72equipmentcabinet.Followthemountinginstruc-
tionsenclosedwiththeL72cabinet.
TheC38canalsobecustominstalledina pieceoffurnitureorcabinetofyourchoice.
TherequiredpanelcutoutandunitdimensionsareshownonPage18ofthismanual.
AlwaysprovideadequateventilationforyourC38,eventhoughitdevelopsverylittleheat.
Cooloperationinsuresthelongestpossibleoperatinglifeforanyelectronicinstrument.Do
notinstallyourC38directlyabovea heatgeneratingcomponentsuchasa highpowered
amplifier.Ina systemstack,thepoweramplifiershouldalwaysbeatthetop.Ifallthecom-
ponentsareinstalledina singlecabinet,a quietrunningventilationfancanbea definiteasset
inmaintainingallthesystemcomponentsatthecoolestpossibletemperatures.
Acustomcabinetinstallationshouldallowthefollowingrecommendedminimumspacing
dimensionsforcooloperation.Allowatleast1 1/2inches(3.8cm)abovetheunitsoairflow
isnotobstructed.Allow17inches(43.2cm)depthbehindthemountingpanel,whichincludes
clearanceforconnectors.Allow1 1/8inches(2.9cm)infrontofthemountingpanelforknob
clearance.
The back cover of this manual folds out to show photographs of the front and rear
panels of the C38. Fold it out to assist you in identifying and locating the front panel
controls, switches, pushbuttons, and the rear panel connectors. The letters and
numbers on the photographs refer to the information that follows.
A.BASSANDTREBLE
Provide12dBboostandcut,withneutralflatresponseatthecenterdetentposition.The
BassandTreblecontrolsaffectonlytheMAIN,SWITCHED1 and2 andBALANCED(Area
A)outputs.
B.RECORD
SelectstheprogramsignalthatwillfeedtheTAPE1,TAPE2,TAPE3 andAreaB OUT-
PUTjacks.
C.INFRAREDSENSOR
ThisIRsensoracceptscommandsfromtheHR38handheldremotecontroller.
D.LISTEN
SelectstheprogramsignalthatfeedstheMAIN,SWITCHED1 and2,andBALANCED
(AreaA)outputs.
E.VOLUME
AdjuststhevolumelevelattheMAIN,SWITCHED1 and2,ANDBALANCED(AreaA)
outputs.ThevolumelevelcanbecontrolledbymanuallyadjustingtheVOLUMEknob,orpress-
ingtheappropriate(Up)or(Down)buttonontheHR38handheldRemoteController.
ThevolumeleveliscontrolledinremoteAreaB byusingtheHR38transmittingtoa
wallmountedIRsensororbya WK-1keypad.
TheTAPEOUTPUTandAreaB volumelevelsarenotaffectedbytheC38frontpanel
VOLUMEcontrolsettings.
TURNONCHARACTERISTICS
AreaA:TheProgramsignalandvolumesettingslastusedwillbeineffect.
AreaB:TheTunersignalswillautomaticallybeselectedwithvolumeat50dBbelowmaximum.
6
FRONTPANEL
CONTROLS,
SWITCHES
AND
PUSHSBUTTONS
HOWTO
INSTALL
THEC38

FandG.LOUD(loudness)andBALANCE(concentriccontrols)
BALANCEcontrol,(largeouterknob),adjuststhevolumeofthechannelsrelativetoeach
other.TheBALANCEcontrolaffectsonlytheMAIN,SWITCHED1 and2,andBALANCED(Area
A)outputs.
L,(Left):Turnthecontroltothelefttoaccenttheleftchannelbyreducingthevolume
oftherightchannel.
R,(Right):Turnthecontroltotherighttoaccenttherightchannelbyreducingthevolume
oftheleftchannel.
LOUDnesscontrol,(smallinnerknob),providesfrequencyresponsecontouredtocompen-
sateforthebehaviorofthehumanearatsofterlisteninglevels.Atthefullycounterclockwise
detentposition,thefrequencyresponseisperfectlyflatandtheloudnesscircuitcomponents
areremovedfromthesignalpath.Turnthecontrolclockwisetomodifythefrequencyresponse
inthecorrectproportionrequiredforsofterlisteninglevels.Thecompensatedfrequency
responseisnotaffectedbychangesinthevolumecontrolsettings.Firstadjustthevolume
forthedesiredlisteninglevel,thenadjusttheLoudnessControltothesettingyoupersonally
prefer.
TheLoudnessControlaffectsonlytheMAIN,SWITCHED1 and2,andBALANCED(Area
A)outputs.
NOTE: The flat frequency response setting of the LOUDness Control is at the fully COUNTER
CLOCKWISE position, not at the center or 12 o'clock position where the Balance Control is
neutral.
THESIXPUSHBUTTONSAREPRESSANDRELEASE,WITHREDLEDINDICATORSTOSHOW
THESELECTEDOPERATINGMODES.
H.RECordLOCK
PresstheRECordLOCKbuttontotemporarilydisabletheAreaB IRsensorsotheunit
cannotbecontrolledbytheHandHeldHR38.AnexampleofthisfeatureallowstheC38to
besetuptorecorda programontape,withoutdangerofsomeoneaccidentallychanging
thepreviouslymadesettings.TheredLEDabovethepushbuttonwillblinkonandofftoin-
dicatetheRECordLOCKfunctionisoperating.
I.MONOphonic
PresstheMONObuttontoaddtheleftandrightchannelsignalstogetherformonoopera-
tion.TheMAIN,SWITCHED1 and2,andBALANCED(AreaA)outputswillallbemono.A
redLEDabovetheMONOpushbuttonwilllighttoindicatetheMONOmodeofoperation.
MONOoperationdoesnotaffecttheTAPEandAreaB outputs,whicharealwaysstereo.
J.MUTE
PresstheMUTEbuttontoturnoffthesignalsattheMAIN,SWITCHED1 and2,and
BALANCED(AreaA)outputs.A redLEDabovetheMUTEpushbuttonwillblinkonandoff
toindicatesignalsaremuted.PressMUTEagaintorestorenormalsound.TheTAPEandArea
BoutputsarenotaffectedbythefrontpanelMUTEpushbutton.
AreaB canbemutedbypressingtheMUTEpushbuttonontheHR38,wheninArea
B,andtransmittingtotheIRsensorlocatedinthatarea.
K.HEADPHONES
Plugina pairoflowimpedancedynamicheadphonestothisjackforheadphonelistening.
L.SPEAKERS1 AND2
PressSPEAKERS1 toturnontherearpanelSWITCHED1 OUTPUTjacks.Theseout-
putsallowyoutoswitchC38signalstootherpoweramplifiersoraccessories.Pressthepush-
7
FRONTPANEL
CONTROLS,
SWITCHES
AND
PUSHBUTTONS

buttonagaintoturnthesignalsoff.A redLEDwilllighttoindicatewhichoutputsareturnedon.
IftheoptionalSCR-3SwitchingRelayisbeingusedwiththeC38,thepairofspeakers
connectedtotheSpeaker1 terminalswillbeturnedONorOFFwiththeSPEAKERS1
pushbutton.
PressSPEAKERS2 toturnonoroff,thesecondsetofoutputsorspeakerterminals
ina similarmanner.
TheSPEAKERS1 and2 pushbuttonshavenoeffectontheMAIN,BALANCED,AreaB
orTAPEoutputs.
M.POWER
PressthePOWERpushbuttontoturntheC38systemoninAreaA.Pressagaintoturn
off.TheentireC38frontpanelnomenclaturewillilluminatewhenthepowerison.
TurnonAreaB anditsdedicatedpoweramplifierbypressingtheHR38POWERpushbut-
tonwheninAreaB whereitsareaIRsensorislocated.WhenAreaB firstcomeson,the
Tunersignalswillautomaticallybeselectedata volumelevel50dBbelowmaximum.Allthe
programaccessoryunitsconnectedtotheC38SwitchedACoutletwillalsoturnon,allowing
youtoselectanydesiredsignal.
TheC38frontpanelwillbeilluminated,buttheMAINorAreaA willbeinMutemode.To
restoreoperationinAreaA,pressthePOWERbuttoneitherontheC38frontpanelorwith
theHR38.AreaA canbeturnedononlyinAreaA.
ALL THE ABOVE OPERATING FUNCTIONS CAN BE PERFORMED AT THE C38 FRONT PANEL,
AS WELL AS BY PUSHBUTTONS ON THE HR38 HAND HELD REMOTE CONTROLLER.
ThedescriptionsbelowoftheHR38
pushbuttonsrefertothenumbersonthe
photograph.
1.Selectanyoftheeightprogramlisten
signalsources.
2.SelecteitherTunerstationpresets,orrelay
operationontheHC-1HomeController.First
presstheHOMEpushbuttonandthenpress
thedesirednumberbutton0 through9 within
5secondstoactivaterelaysintheHC-1.
3.Selectadditionalaudio/videoprogram
signalsourceswhentheoptionalMcintosh
MVS-3Audio/VideoSelectorisadded.You
mustfirstpresstheC38VIDEOinput
pushbuttonbeforepressinganyofthefive
pushbuttonsthatoperatetheMVS-3.
4.SelectTunerfunctions,AM,FM,Search
orSeek.
5.SelectCDPlayer,CDChangerorTapeRecorderfunctions.
Whenusinga McintoshsingleplayCDplayer,thefunctionsareSTOP,BACKTRACK,NEXT
TRACKandPLAY.
8
FRONTPANEL
CONTROLS,
SWITCHES
AND
PUSHBUTTONS
HR38
HANDHELD
REMOTE
CONTROLLER

Whenusinga McintoshCDChanger,thefunctionsareSTOP,BACKTRACK,NEXTTRACK
andPLAY.IntheSTOPposition,BACKTRACKselectswhichdisctoplay,andNEXTTRACK
selectstheSINGLEdisc.
Whenusinga compatibleTapeRecorder,thefunctionsareSTOP,FASTREWIND,FASTFOR-
WARDandPLAY.
6.PressHOMEtooperateHC-1HomeControllerfunctions,thenwithinfiveseconds,press
apushbuttonfrom0 through9 tooperatethedesiredrelaysontheHC-1.
7.PressSYSOFFtoturntheentireC38systemOFFfromeitherAreaA orAreaB.
8.PressPOWERtoturnonthemainsysteminAreaA.PressinAreaB toturnonjustremote
AreaB.
9.SelectSwitchedOutputs1 or2,andSpeakers1 or2,(whenoptionalSCR-3isbeingused).
10.Presstomutesignals.
11.Press(Up)toraisevolume,and(Down)tolowervolume.
HOWTOINSTALLBATTERIESINTHEHR38HANDHELDREMOTECONTROLLER
Slideopenthebatterycompartment.InserttwotypeAAbatteriesintothecompartment,
makingsuretoobservethebatterypolaritiesindicatedinthebatterycompartment.
Whenthebatteriesarenearingexhaustion,theeffectiverangeoftheremotecontroller
decreases,andMAYevenfailtooperate.Inthiscase,replacebothbatterieswithfreshones.
NOTE:
1.Donotmixoldandnewbatteries.UseONLYbatteriesthatarenew.
2.Makesurebothbatteriesareofthesametypeandidentical.
3.Topreventdamagecausedbypossiblebatteryleakage,removethebatteriesfromtheremote
controllerifitisnotgoingtobeusedforanextendedperiodoftime.
4.Neverdismantlebatteriesordisposeofthem ina fire,astheymayexplode.Disposeof
oldbatteriesinanapprovedmethodforpropersafety.
UsehighqualitycablestointerconnecttheC38withitsassociatedequipment.Quality
cableswillensurethebestpossibleperformancefromyourMcintoshstereosystem.Your
Mcintoshdealercanadviseyouonthetypeandlengthsofcablesbestsuitedforyour
installation.
LISTENOUTPUTFUNCTIONS
1.BALANCEDOUTPUTS(AreaA Only)
Connecta cablewithanXLRtypebalancedconnectorfromeachoftheC38BALANC-
EDOUTPUTjackstothebalancedinputjacksofa poweramplifier.
Usingbalancedconnectorsandcablescanreducenoiseorinterferencebyasmuch
as40dBespeciallyifthecablesarequitelong.Iftwoseparatemonopoweramplifiersare
usedina stereosystem,usingbalancedcablescanreducethepossibilityofhumpickup.
IfcablelengthsbetweentheC38anda stereopoweramplifierareonemeterorless,regular
unbalancedcablesareusuallyperfectlyadequate.
BalancedJackPinConfiguration:
Pin1.SystemGround
Pin2.+ Output
Pin3.- Output
9
HR38HANDHELD
REMOTE
CONTROLLER
THEREARPANEL
AND
HOWTOMAKE
CONNECTIONS

2.SWITCHED1 and2 OUTPUTS(AreaA only)
Twoadditionalpoweramplifiersoraccessorycomponentscanbeconnectedtothe
SWITCHED1 and2 Outputs.Audiosignalsarefedtotheseoutputsonlywhentheappropriate
frontpanelSPEAKERS1 or2 pushbuttonsarepressed.Thisswitchingcapabilityisuseful
whenadditionalpoweramplifiersareusedtofeedremoteareaspeakers.
Connecta pairofshieldedcablesfromeitheroneorbothpairsofSWITCHEDOUTPUT
jackstotheinputjacksofeitheroneortwopoweramplifiers.
3.MAINOUTPUTS(Unbalanced)
Connecta pairofshieldedcablesfromtheMAINoutputstotheinputsofa poweramplifier.
SignalsarefedtotheMAINoutputswhenevertheC38isonandoperating.
4.AREAB OUTPUT
WhateversignalisselectedbytheRECORDinputselectorswitchalsoappearsatthe
AreaB outputjackswhenAreaB isON.Thissignalcanbefedtoanotherpoweramplifier
connectedtoa pairofspeakersina remotearea.ThevolumelevelinAreaB iscontrolled
onlybytheHR38transmittingtoa wallmountedIRsensor,orbytheWK-1keypad.
5.(LISTEN)PROCESSORFROMANDTO
AnexternalsignalprocessorcanbeaddedtotheC38whichwillaffectonlythe(LISTEN)
MAIN,SWITCHED1 and2,(AreaA)outputs.ThePROCESSORFROMjackshavebuilt-in
switchingcontactsthatallownormalsignalstopassthroughwhennocablesareconnected.
Whenanexternalsignalprocessorisproperlyconnected,theprogramsignalswillfeedto
theprocessorfromtheC38PROCESSORTOjacks,andreturntotheC38atthePROCESSOR
FROMjacks.
Connecta pairofcablesfromtheexternalprocessorOutputjackstotheC38LISTEN
PROCESSORFROMjacks.ConnectanotherpairofcablesfromtheexternalprocessorInput
jackstotheC38LISTENPROCESSORTOjacks.
WHEN AN EXTERNAL SIGNAL PROCESSOR IS CONNECTED TO THE C38 LISTEN PRO-
CESSOR JACKS, THE PROCESSOR MUST BE TURNED ON AND OPERATING, OR IN BYPASS
MODE, FOR A PROGRAM TO BE HEARD THROUGH THE SYSTEM IN AREA A.
RECORDOUTPUTFUNCTIONS
6.TAPEOUTPUTS1,2,AND3
Theseoutputsprovidesignalstofeedasmanyasthreeseparatetaperecorders.The
programthatappearsattheTAPEOUTPUTSisdeterminedbythesettingofthefrontpanel
RECORDSwitch.
(The program signal selected by the RECORD Switch also appears at the Area B output jacks
when Area B is ON.)
Connecta pairofcablesfromtheC38TAPE1 OUTPUTStothehighlevelinputsofa
taperecorder.Connectcablestoa secondandthirdtaperecorderina similarmannerfrom
TAPE2 and3 OUTPUTS.
7.(RECORD)PROCESSORFROMandTO
AnexternalsignalprocessorcanbeconnectedtotheC38whichwillaffectonlythe
TAPERECORDandAreaB Outputs.ThePROCESSORFROMjackshavebuilt-inswitching
contactsthatallownormalsignalstopassthroughtotheTAPEOUTPUTSwhennocables
areconnected.Whenanexternalprocessorisproperlyconnected,theRECORDsignalswill
feedtotheprocessorfromtheC38PROCESSORTOjacks,andreturntotheC38atthePRO-
CESSORFROMjacks.
10
THEREARPANEL
AND
HOWTOMAKE
CONNECTIONS

Connecta pairofcablesfromtheprocessoroutputjackstotheC38RECORDPRO-
CESSORFROMjacks.Connectanotherpairofcablesfromtheprocessorinputjackstothe
C38RECORDPROCESSORTOjacks.
WHEN AN EXTERNAL SIGNAL PROCESSOR IS CONNECTED TO THE C38 RECORD PRO-
CESSOR jacks, THE PROCESSOR MUST BE TURNED ON AND OPERATING, OR IN BYPASS
MODE, FOR A PROGRAM TO BE FED TO THE TAPE OUTPUTS OR AREA B OUTPUTS.
AUDIOINPUTS
8.VIDEO
Usetheseinputsforaudiosignalsfromaccessoriessuchasa LaserDiscplayer,VCR,
TVreceiverorMVS-3Audio/VideoSelector.Connecta pairofcablesfromthevideoaccessory
outputstotheC38VIDEOinputs.
WhentheVIDEOinputsareselected,dataisalsoavailableattheVIDEODataportto
feedtheoptionalMVS-3VideoSelectorforswitchingfiveadditionalaudio/videosignals.
9.TAPE1,2 and3
AtotalofthreetaperecorderscanbeconnectedtotheC38.TheseparateLISTENand
RECORDselectorswitchesallowrecording,andlisteningtotheoriginalsignalormonitoring
therecordedsignalfroma threeheadrecorder.TheTAPEinputscanalsobeusedforother
accessoryaudioequipmentwithsimilaroutputlevels.
Connecta pairofcablesfromtheoutputsofa taperecordertotheappropriate1,2 or
3,C38TAPEinputs.(ConnectthetaperecorderOutputsasindicatedinStep6 above.)
IF MORE THAN ONE TAPE RECORDER IS CONNECTED FOR BOTH RECORD AND
PLAYBACK, MAKE CERTAIN THAT THE INPUTS AND OUTPUTS OF EACH RECORDER ARE
CONNECTED TO THE SAME MATCHING NUMBER JACKS.
When a C38 is connected to a CR10 Remote Control System, only TAPE 1 and TAPE
2can be accessed from the CR 10.
10.TUNER
Connecta pairofcablesfromtheoutputsofa tunertotheC38TUNERinputs.Connect
theControlcablefromtheC38TUNERCONTROLconnectortothematchingconnectoron
aMcintoshtuner.ThisallowsyoutocontroltuneroperationwiththeHR38handheldremote
controllerora WK-1keypad.
11.CD1andCD2
Connecta pairofcablesfromtheoutputsofa CDplayertoeitherpairofC38CDIN-
PUTS.Forexample,CD1inputscouldbeusedfora singlediscplayer,andCD2inputsfor
aCDchanger.
When a C38 is connected to a CR 10 Remote Control System, only CD2 can be selected
from the CR 10.
12and13.PH/AUX(PHono/AUXiliary)
BoththePHonoandAuxiliaryinputsareselectedbythesamepositiononthefrontpanel
LISTENandRECORDselectorswitches.EitherthePHonoInputs,ortheAuxiliarycanbe
used,butnotbothatthesametime.Whena pairofcablesisconnectedtotheAuxiliary
inputjacks,thePHonosectionisautomaticallybypassed.
Auxiliary:Connecta pairofcablesfromtheaudiooutputsofanaccessoryunittothe
C38AUXinputs.
To use the PHono inputs, FIRST remove any cables connected to the AUX inputs.
11
THEREARPANEL
AND
HOWTOMAKE
CONNECTIONS

PHono:Connecta pairofcablesfroma recordplayerwitha movingmagnettypephono
cartridgetothePHinputs.
14.GND(Ground)
Ifthephonoplayerbeingusedhasa separateGroundlead,connectittotheGND
terminal.
15.CD1andCD2CONTROL
ConnectControlcablesfromtheC38CD1andCD2CONTROLconnectorstothemat-
chingconnectorsona McintoshCDplayerandchanger.Thisconnectionallowsyoutocon-
troltheCDunitsfromtheHR38ora WK-1wallmountedKeypad.
ConnectcablesfromtheC38,CD1orCD2DATAPORTStotheDataInputsona CD
playerandchanger.TheseconnectionsallowyoutocontroltheCDunitswiththeirownhand
heldremotecontrollerstransmittingdirectlytotheC38frontpanelorremoteIRsensors.
16.TOMULTI-ROOMCONTROLLER
This25pinconnectorallowsyoutoadda McintoshCR10RemoteControlSystem.The
CR10canprovideasmanyasfouradditionalremotecontrolledlisteningareas,fora total
ofsix.AdditionalCR10unitscanalsobecascadedforevenmorecontrolareas.EachCR10
addsthecapabilityoffourareas.
AllprogramsignalsourcesconnectedtotheC38,exceptforTape3 andCD1,areavailable
forselectionbya CR10.
17.TUNERCONTROL
Connecta controlcablefromtheC38TUNERCONTROLjacktothematchingjackon
aMcintoshtuner.ThisconnectionallowsyoutooperatethetunerwiththeHR38orWK-1
wallmountedKeypad.
18.SCR(OptionalSpeakerControlrelay)
TheMcintoshSCR-3SPEAKERCONTROLRELAYprovidescapabilityforswitchingtwo
pairsofspeakersusingthefrontpanelSPEAKERS1 and2 pushbuttons.TheSCR-3alsoin-
cludestwohighcurrentACoutletswitha totalcurrentcapacityof1800wattstooperateac-
cessorycomponentssuchaslargepoweramplifiers.Theseoutletsturnonandoffwiththe
C38POWERswitchandcanbeusedwhentheaccessorycomponentsdemandmorecur-
rentthanthe1400wattratingoftherearpanelACoutletscontrolledbytheC 38Powerswitch.
PlugtheninepincomputertypeconnectorfromtheSCR-3intotheSCRsocketonthe
C38rearpanel.PlugtheheavyACcablefromtheSCR-3intoa walloutlet.
DO NOT PLUG THE SCR-3 HEAVY AC CABLE INTO ANY OF THE C38 REAR PANEL AC
OUTLETS.
AC power control for additional accessories can be accommodated by adding the
optional Mcintosh R612 or PC-2 AC Power Controller.
19.EXTERNALSENSORS,AREAA andAREAB
Acoaxialconnectorisprovidedfora remoteIRsensortocontrolAreaA,inaddition
tothebuilt-infrontpanelsensor.TheexternalsensorcanbeeithertheR649wallmounted
sensor,ortheWK-1Keypad.
AcoaxialconnectorisalsoprovidedforanIRsensororkeypadforremotecontrolinAreaB.
ThewallmountedR649IRsensorandtheWK-1keypadhavea statusindicatorbuiltin.
AredLEDlightswheneverthesystemisonandoperating.TheLEDwillblinkonandoffwhen
theareaismuted.
12
THEREARPANEL
AND
HOWTOMAKE
CONNECTIONS

BoththeIRsensorandthekeypadconnecttotheC38EXTERNALSENSORSwitha single
R659/UorRG6coaxialcable.TheC38IRpowersupplywillallowconnectinguptofourIR
sensorsorkeypadsinparallelonthesamecoaxialline.
20.DATAPORTS
Ninedataoutputportsareprovided.Theseallowcontrolofcompatibleremotecontrolled
accessorieswiththeirownhandheldcontrollerstransmittingdirectlytoa C38IRsensor.
TheVIDEOportallowsdatatobefedtoanoptionalMcintoshMVS-3Audio/VideoSelector
forswitchingfiveadditionalaudio/videosignals.
AHOMEportallowsdatatobefedtoanoptionalMcintoshHC-1HomeControllerforcon-
trolofexternalaccessoriesorappliances.
21.POWERCONTROL
Thisconnectorsuppliesa Logic1 controlsignaltofeedtoa PowerControlInputona com-
patibleaccessorytoturnonandoffitsACpower.
22.ACOUTLETS(TOTALOFFOUR)
AnUNSWITCHEDACoutletstaysonatalltimeswhentheC38isconnectedtoa liveAC
walloutlet.Thisoutletcanbeusedforanaccessorythatstaysonallthetimesuchasa
clockorVCRthatmaybeprogrammedtorecordwhenthemainsystemisturnedoff.
ASWITCHEDACoutletturnsonwhenevertheC38isturnedonineitherAreaA orArea
B,andcanbeusedtopoweranyaudioorvideoaccessoryusedinthesystem.Toexpand
thesingleACswitchedoutletcapability,a powercontrollersuchastheR612orPC-2can
beused.
AREAA PWRAMPturnsonACtothepoweramplifierconnectedforuseintheMain,Area
AwhenevertheC38isturnedon.
AREAB PWRAMPturnsonACtothepoweramplifierconnectedtotheAreaB Outputs.
TheAreaB amplifiercanonlybeturnedonbytheHR38orWK-1keypadinAreaB.
TOTALCURRENTCAPACITYOFC38REARPANELACOUTLETSIS1400WATTS
13
THEREARPANEL
AND
HOWTOMAKE
CONNECTIONS

PERFORMANCELIMITS
Performancelimitsarethemaximum
deviationfromperfectionpermittedbya
Mcintoshinstrument.Wepromiseyouthat
whenyoupurchasea newC38froma
McintoshfranchisedDealer,itwillbe
capableofperformanceatorbetterthan
theselimits.
FREQUENCYRESPONSE
+0,-0.5dBfrom20Hzto20,000Hz
RATEDOUTPUT
2.5VatMAIN,SWITCHED1 and2,
BALANCEDandAreaB Outputs
OUTPUTIMPEDANCE
600ohmsforMAIN,SWITCHED1 and2,
BALANCEDandAreaB Outputs
MAXIMUMOUTPUTVOLTAGE
8Vfrom20Hzto20,000HzatMAIN,
SWITCHED1 and2,BALANCEDandArea
BOutputs
TOTALHARMONICDISTORTION
0.002%maximumfrom20Hzto
20,000Hzatratedoutput
SENSITIVITY
Phono:2.5mVfor2.5Vratedoutput,
(0.5mVIHF)
HighLevel:250mVfor2.5Vratedoutput,
(50mVIHF)
SIGNAL-TO-NOISERATIO,A-WEIGHTED
Phono:90dBbelow10mVinput,
(84dBIHF)
HighLevel:105dBbelowratedoutput,
(95dBIHF)
MAXIMUMINPUTSIGNAL
Phono:90mV
HighLevel:10V
INPUTIMPEDANCE
Phono:47Kohmsand65pFcapacitance
HighLevel:22Kohms
VOLTAGEGAIN
PhonotoTape:40dB
PhonotoMain:60dB
HighLeveltoTape:0dB
HighLeveltoMain:20dB
TONECONTROLS
BassandTreblevariable,12dBboostto
12dBcut
ACPOWEROUTLETS
(TOTAL CURRENT CAPACITY OF ALL
FOUR OUTLETS IS 1400 WATTS)
OneUnswitched
OneSwitchedforAreaA poweramplifier
OneSwitchedforAreaB poweramplifier
OneSwitchedforaccessories
POWERREQUIREMENTS
120V,50/60HZ,25Watts
MECHANICALINFORMATION
SIZE
FrontPanel:171/2inches(44.5cm)wide,
by5 3/8inches(13.7cm)high
Depthbehindmountingpanelincluding
clearanceforconnectors:17inches
(43.2cm)
KnobclearancerequiredinfrontofMoun-
tingPanel:1 1/8inches(2.9cm)
FINISH
FrontPanelisglass,withgold/teal
nomenclatureillumination.Thechassisis
black.
WEIGHT
20pounds(9.1Kg)net,35pounds(15.9Kg)
inshippingcarton
14
SPECIFICATIONS

ToneControlResponse
ControlAtMinimum,CenterAndMaximum LoudnessControlResponse
FREQUENCYINHERTZ FREQUENCYINHERTZ
RMSOutputVolts
%HARMONICDISTORTION
HarmonicDistortionvsFrequency
AtRatedOutput
FREQUENCYINHERTZ
15
PERFORMANCE
CHARTS
%HARMONICDISTORTION
HarmonicDistortionvsVoltageOut
TunerInToMainOut
RESPONSEINdB RESPONSEINdB

LOGICDRIVENCONTROL
AllInputs,Outputs,CD,Tuner,SCRandVideoselectorlinesarecontrolledbylogiccircuits
intheC38.ThislogicischangedbyfrontpanelswitchesorbytwomicroprocessorIRdecoders,
oneforLISTEN/MAIN(AreaA),andoneforRECORD(AreaB).Thesemicroprocessorsare
programmedwithexclusiveMcintoshsoftware.TheyreceivedatafromtheC38frontpanel
IRsensor,orfromexternalIRsensorsandprovidethecommandsignalsforallswitching
functionsandvolumecontrol.A thirdmicroprocessordecodestheCD1,CD2andTUNER
Controlcommands.
ThelogiccircuitsactivateElectro-Magneticswitchesforthefinalstepinallsignalswitching.
ELECTRO-MAGNETICSWITCHING
AllsignalswitchingintheC38isdonebyELECTRO-MAGNETICmethods.ELECTRO-
MAGNETICswitchingisanoldandproventechnologythathasbeenupgradedwithmodern
materialsandmanufacturingtechniques.
Eachswitchconsistsofa sealedglasstubefilledwithaninertoxygenfreeatmosphere,
withtinyleadsprotrudingfromeitherend.Theseleadsextendintothetubeandoverlapone
anotherwitha separationofa fewthousandthsofaninch.Theleadsaremadefroma ferrous
materialthatisinfluencedbya magneticfield.Theyarefirstplatedwithgoldasa basematerial,
thenwithrhodiumandruthenium.Rutheniumisthebestcontactmaterialknown.Theglass
assemblyisthenplacedinthecenterofa multi-layercoilofcopperwire.Theentireassembly
ismoldedtogetherina toughshockabsorbingplastic.Theswitchandcoilconnectionsex-
tendfromthebottomintheformofprintedcircuitboardterminals.
Whena DCvoltageisappliedtothecoil,currentflowsandcreatesa magneticfield.The
forceofthefieldcausestheleadstobendandcontactoneanotherinsidethesealedglass
tube.Theinertoxygenfreeatmosphereeliminatescorrosionofthecontacts,insuringa low
resistance,distortionfreeswitch.TheswitchingcontrolsignalscomefromtheC38logic
circuits.
PHONOPREAMPLIFIER
Thephonopreamplifierusesa hightechnologyintegratedcircuitoperationalamplifierthat
hasanextremelywidefrequencyrangecapability.Itsdifferentialinputstagehasbeenop-
timizedforlownoiseandlowdistortion.Theopenloopgainforthiscircuitis100,000.With
highopenloopgain,a largeamountofnegativefeedbackcanbeusedaroundthispreamplifier
sectiontoreducenoiseanddistortiontoanextremelylowvalue.Thefeedbacknetworkalso
providesprecisionRIAAfrequencyequalizationwhichfollowstherequiredresponsecurve
veryaccuratelythroughouttheentireaudiorange.Thenetworkuses1%tolerancemetalfilm
resistorsand5%tolerancepolypropylenecapacitors.
Toachievelow-noiseperformance,itisessentialthatthefeedbacknetworkhaveverylow
impedance.A circuitdesignofthistypeactsasa smallpoweramplifier.Thispreamplifier
sectionwillactuallyproducemorethan100milliwattsoutputpower.Thisextramarginofper-
formanceresultsina phonopreamplifierwithextremelylowdistortionandnoise.
Thispreamplifiercircuithasa verywidedynamicrange.Itwillacceptupto90millivolts
ofinputsignalwithoutoverload.Thisisfargreaterthanthemaximumoutputvoltagecapability
ofanycurrentmodelmagneticphonocartridge.
Thesensitivityofthiscircuitis2.5millivoltsfor2.5voltsatthemainoutput.Thegainis
40dBat1000Hz.A signalinputof10millivoltsresultsin1 voltattheTapeOutputs.TheTape
Outputsourceimpedanceofthephonopreamplifierislessthan100ohms,andwilldrive
aloadimpedanceof1000ohmsorhigher.
16
TECHNICAL
DESCRIPTION

LOUDNESSAMPLIFIER
Highlevelsignalsfeedintothepreamplifierpasttheinputandmodeswitching,through
thevolumecontrolandthenintotheloudnessamplifier.TheC38usesanactiveloudness
controlcircuitdesign.Anintegratedcircuitoperationalamplifierisusedwithtwoseparatefeed-
backcircuits.Onefeedbackloophasflatfrequencyresponse,andtheotherloophasloudness
compensation.A potentiometerplacedbetweenthesetwofeedbackloopsmakesitpossible
toselectanydegreeoffrequencyresponsefromflat,tofullloudnesscompensation.The
overallgainoftheloudnesscircuitis20dB,whichremainsconstantatmidfrequencies,
regardlessofthepositionoftheloudnesscontrol.Thebassandtreblecompensationincrease
fromthereferencegain,andthedesiredamountofloudnesscompensationcanbeselected
atanyvolumecontrolsetting.
TONECONTROLAMPLIFIER
Thetonecontrolamplifieruseshightechnologyintegratedcircuitoperationalamplifiers.
Theoutputstageshavebeenoptimizedforoptimumtransientperformanceandminimum
distortion.Anothersetofoperationalamplifiersisarrangedina circuitconfigurationequivalent
toseriestunedcircuits.Theseriestunedcircuitscanbeinsertedintoeithertheinput,or
thefeedbackloopbymeansofa potentiometer.Theproperchoiceofcircuitcomponents
resultsina 12dBboostorcutatthedesiredbassandtreblefrequencies.Whenthetone
controlpotentiometersareattheircenterordetentpositions,alltonecontrolelementsare
removedfromthesignalpath,andthefrequencyresponseisperfectlyflat.
SYSTEMEXPANSIONCAPABILITY
Audiobufferanddataswitchesfeedallrequireddataandsignalstoa rearpanel25pin
subminiature"D"connectorforsystemexpansion.A McintoshCR10RemoteControlsystem
canbeaddedusingthisconnectortoaddthecapabilityofcontrollinguptofouradditional
remoteareas.
17
TECHNICAL
DESCRIPTION

C38CUSTOMMOUNTING
17.1/2"
444mm
-BOTTOMOFCUTOUTANDTOP
OFSUPPORTSHELFMUST
COINCIDE
6X 1/2
WOODSCREW
ANDWASHER
18
INSTALLATION
DIAGRAM
SUPPORTSHELF
6-32X 3/8
MACHINESCREW
ANDWASHER
(SIDEVIEW) MOUNTINGBRACKET
ATBOTHSIDESOF
REARPANEL
OUTLINEOFUNIT
ALLOWATOTALOF17"(43.2cm)
FORADEQUATECLEARANCEOFTHE
VARIOUSCONNECTORSTHATMAYBEUSED
MOUNTINGSURFACE
ENDCAPS
ARE
5.3/8"
136.9mm
4.7/8"
123.8mm
PANEL
HEIGHT
IS
5.5/16"
134.9mm
EDGEOFCUTOUT
17"
433.4mm
SUPPORTSHELF
OUTLINEOFFRONTPANEL