McIntosh MX113 User manual

ReadingTime:45Minutes
Price$1.25
THEMclNTOSHMX113FM/FMSTEREO-AMTUNER-PREAMPLIFIER

YourMX113AM-FM/FMstereotuner
andstereopreamplifierwillgiveyou
manyyearsofpleasantandsatisfactory
performance.Ifyouhaveanyquestions
pleasecontact—
CUSTOMERSERVICE
MclntoshLaboratoryInc.
2ChambersStreet
Binghamton,NewYork13903
Phone:[phone]
WARNING:TOPREVENTFIREOR
SHOCKHAZARD,DONOTEXPOSE
THISUNITTORAINORMOISTURE.
TakeAdvantageof3 years
ofFREEService...
FillintheApplicationNOW.
THREEYEARSERVICECONTRACT
Anapplicationfora FREETHREEYEARSERVICECONTRACTisincludedwiththismanual.
Thetermsofthecontractare:ormishandlingisnotcoveredbytheSERV-
ICECONTRACT.
1.Mclntoshwillprovideallparts,materialsand
laborneededtoreturnthemeasuredperform-
anceoftheinstrumenttotheoriginalper-
formancelimitsfreeofanycharge.The
SERVICECONTRACTdoesnotcoveranyship-
pingcoststoandfromtheauthorizedservice
agencyorthefactory.
2.AnyMclntoshauthorizedserviceagencywill
repairallMclntoshinstrumentsatnormal
servicerates.Toreceivethefreeserviceunder
thetermsoftheSERVICECONTRACT,the
SERVICECONTRACTCERTIFICATEmustac-
companytheinstrumentwhentakentothe
serviceagency.
3.Alwayshaveservicedonebya Mclntosh
authorizedserviceagency.Iftheinstrument
ismodifiedordamaged,asa resultofun-
authorizedrepairtheSERVICECONTRACT
willbecancelled.Damagebyimproperuse
4.TheSERVICECONTRACTisissuedtoyouas
theoriginalpurchaser.Toprotectyoufrom
misrepresentationthiscontractcannotbe
transferredtoa secondowner.
5.ForyourprotectionMclntoshselectsonly
dealerswhohavetechnicalcompetenceto
guidepurchasersfairly,andprovideservice
whennecessary.ToreceivetheSERVICE
CONTRACTyourpurchasemustbemade
froma Mclntoshfranchiseddealer.
6.Yourcompletelyfilledinapplicationfora
SERVICECONTRACTmustbepostmarked
within30daysofthedateofpurchaseof
theinstrument.
7.ToreceivetheSERVICECONTRACTallin-
formationontheapplicationmustbefilled
in.TheSERVICECONTRACTwillbeissued
whenthecompletelyfilledinapplication
isreceivedatMclntoshLaboratoryIncor-
poratedinBinghamton,NewYork.
Copyright© 1971byMclntoshLaboratoryInc.
CONTENTS
ServiceContract1
Installation2,3
HowtoConnect4,5
WhattheControlsDo
AndHowtoUseThem6,7
UsingthePushbuttons7
BalancingYourStereo8
ListeningtoYourStereo9
PerformanceLimitsand
Ratings10,11
PerformanceCharts12,13,14
TechnicalDescription15,16,17
BlockDiagrams18,19
StationLog20
1

Adequateventilationextendsthetrouble-freelifeof
electronicinstruments.Itisgenerallyfoundthateach10°
centigrade(18°F)riseintemperaturereducesthelifeof
electricalinsulationbyonehalf.Adequateventilationisan
inexpensiveandeffectivemeansofpreventinginsulation
breakdownthatresultsfromunnecessarilyhighoperating
temperatures.Thedirectbenefitofadequateventilation
islonger,trouble-freelife.
Allowatleast15inchesdeepx 17½incheswidex 6
incheshighformountingtheMX113.Alwaysallowforair
flowbyeitherventilationholesorspacenexttothebottom
oftheinstrumentanda meansforwarmairtoescapeat
the top.
Withadequateventilation,theMX113canbemounted
inanyposition.
TopreparetheMX113forinstallationremovethepro-
tectivecovering.TurntheMX113upsidedownsothatit
restsonitstopontheshippingpallet.Removethefour
plasticfeetfastenedtothebottomofthechassis.
Next,placethemountingbrackets,thepartsbagandthe
mountingtemplateathand.
ThePANLOCprofessionalmountingdesigneliminates
theneedforanyshelforbrackettosupporttheMX113.It
iscompletelysupportedbyitsownmountingbrackets.
Thedesignofthemountingtemplateallowsyoutoposi-
tionorlocatethecutoutfromthefrontorrearofthepanel
towhichtheinstrumentistobemounted.Positiontheplas-
ticmountingtemplateovertheareaofthepaneltobecut
outforinstallation.
Ifthecutoutistobelocatedfromthefrontofthepanel,
beginat2.Ifthecutoutistobelocatedfromtherearofthe
panel,beginhere.
1.Onthebackofthecabinetpanel,scribea verticalcen-
terlinethroughtheexactcenteroftheareainwhichthe
cutoutistobemade.
Placethetemplateagainstthebackofthepaneland
matchthetemplatecenterlinewiththecenterlineon
thecabinetpanel.
Makesurethatthereisatleast¼ inchclearancebe-
tweenthebottomofthedashedlineofthecutoutarea
onthetemplateandanyshelforbracebelowthepro-
posedcutout.
Markthetwolocatingholes("C"holesonthemounting
template).
Drillthetwolocatingholes.Becertainthedrillisper-
pendiculartothepanel.
Nowpositionthetemplateonthefrontofthepanelby
aligningthe"C"locatingholesonthetemplatewiththe
drillholes.
2.Ifthecutoutistobelocatedfromthefrontofthepanel:
Withthetemplateinplaceagainstthecabinetpanel,
markthe"A"and"B"drillholesandthefoursmall
holesthatidentifythecornersofthecutout.Jointhe
cornermarkswitha pencil.Theedgeofthetemplate
canbeusedasa straightedge.
2

IMPORTANT:DRILLTHE6 HOLESBEFOREMAKING
THECUTOUT.
Accuratelydrillthethreeholesoneachsideofthecut-
outareawitha 3/16inchdrill.
WiththesawontheINSIDEOFTHEPENCILLINES
carefullycutouttherectangularopening.
Securethemountingstripstotherearofthecabinet
panelusingtwoscrewsfromthehardwarepackage.
Insertthescrewsinthecenterholesofcabinetpanel
("B"holesonthetemplate)andtighten.Thescrewhead
shouldpullintothewoodslightly.(Usetwo¾ inchlong
screwsforpanelsunder½ inch,ortwo1¼inchlong
screwsforpanels½ inchthickandlarger.)
Attachthemountingbracketstothecabinetpanelusing
fourscrews.
Placethetemplateoverthemountingscrews.The
mountingscrewsshouldbecenteredinthe"A"and"B"
holesonthetemplate.Thesidesofthemountingbrackets
shouldmatchtheverticaldashlinesonthetemplate.If
necessary,loosenthescrewsandpushthebracketsinto
alignmentandretighten.
Insertthepowercordthroughtheopening.Carefully
slidetheMX113intotheopeningsotherailsonthebot-
tomoftheequipmentslideinthetrackofthemounting
brackets.Slidetheinstrumentinuntilitstopsattheadjust
positionlatches.Pressthelatchesinandcontinuetoslide
theinstrumentinuntilthefrontpanelisagainstthe
cabinetpanel.Atthebottomcornersofthefrontpanelare
thePANLOCbuttons.DepressingthePANLOCbuttons
willlocktheinstrumentfirmlyintheinstallation.Depress-
ingthePANLOCbuttonsa secondtimewillreleasethe
instrument.Youcanthenslidetheinstrumentforwardto
theinspection-adjustmentposition.Depressingtheinspec-
tion-adjustmentpositionlatcheswillallowtheinstrument
toslidecompletelyoutoftheinstallation.

HowtoConnect
CONNECTINGA RECORDPLAYERTOPHONO1
Connectthecablefromtheleftchanneloftherecord
playerintotheL PHONO1 inputjack.
Connectthecablefromtherightchanneloftherecord
playerintotheR PHONO1 inputjack.
PHONO2 isprovidedfortheuseofa secondrecord
player.
Connectthecablefromtheleftchanneloftherecord
playerintotheL PHONO2 inputjack.
Connectthecablefromtherightchanneloftherecord
playerintotheR PHONO2 inputjack.
AUX
Anyhighlevelprogramsourcesuchasanothertuneror
aTVsetcanbeconnectedtotheinputjacksmarkedAUX.
CONNECTINGA TAPERECORDER
ToRecord
Connecta cablefromtheL TAPEOUTPUTjacktothe
lefthighlevelinputofa taperecorder.
Connecta cablefromtheR TAPEOUTPUTjacktothe
righthighlevelinputofthetaperecorder.
ToPlayback/Monitor
Connectthecablefromtheleftchanneloutputofa tape
recordertothehighlevelinputs. . . L TAPE.
Connectthecablefromtherightchanneloutputofa
taperecordertothehighlevelinputs.. . R TAPE.
CONNECTINGTHEMX113TOPOWERAMPLIFIERS
ConnecttheMAINOUTPUTjackstotheinputofa stereo
poweramplifier.TheL jackisconnectedtotheleftampli-
fierinputjack.TheR jackisconnectedtotherightampli-
fierinputjack.
TheoutputsourceimpedanceattheMAINOUTPUTis
200ohms.Longercablesthansuppliedcanbeusedbe-
tweentheMX113andtheamplifier.Thelengthofthe
cableislimitedbythecapacityofthecable.Thetotal
capacitymustnotexceed1,000pF.Forinstance:cables
witha capacityof25pFperfootmaybe40feetlong.
13.5pFperfootcablemaybe75feetlong.Theinput
impedanceoftheamplifiersshouldbe47,000ohmsor
greater.
L+ R OUTPUT
UsetheL + R OUTPUTtofeedleftplusrightsignaltoa
separatepoweramplifierformonophonicbackground
musicorfora centerchannelspeaker.
CONNECTINGANFMANTENNA
Satisfactorystereowheremonoreceptionhasbeen
satisfactoryrequiresabouttentimesasmuchsignalfrom
theantenna.Monophonicreceptionthatissatisfactory
onanindoorantennamayrequiretheuseofanoutdoor
antennaforstereoreceptionofequivalentquality.
WiththeMX113oneofthreeantennasystemscanbe
used:(1)theindoordipolesuppliedwiththeMX113,
(2)anoutdoorFMantenna,or(3)anallchannel(UHF-VHF-
FM)antenna.Infringeareasbestresultswillprobablybe
obtainedwiththeuseofanoutdoorFMantenna.Inmany
areastheindoordipolemaybesatisfactory.
CONNECTINGANINDOORDIPOLEANTENNA
Theflexiblefoldeddipoleantenna(300ohm)supplied
withtheMX113isforindooruseinurbanorhighstrength
signalareas.
Connectthetwoleadsfromthedipoletotheterminals
markedFMANT(red).Theflexibilityofthethinflatwire
assemblypermitsittobeplacedundera rug,tackedbehind
thestereo...or,placedinanyotherconvenientlocation.
Insomecases,itmaybenecessaryto"position"thean-
tennaforbestsignalreception.Thisshouldbedonebefore
itispermanentlylocatedortackeddown.Keeptheantenna
awayfrommetalobjects.Donotattachtoa metalsurface.
CONNECTINGANOUTDOORFMANTENNA
Anoutdoorantennaisrecommendedforoptimumper-
formanceinallareas.Infringe(outlying)areas,bestresults
willbeobtainedwitha highlydirectionalFMantennaused
inconjunctionwitha rotator.Rotatetheantennauntilthe
bestreceptionisobtained.Connectthe300ohmantennato
theterminalsmarkedFMANT(red).
CONNECTINGA 75OHMCOAXIALANTENNA
Anunbalanced75ohmantennacanbeconnectedtothe
MX113withcoaxialcable.Connectthecenterconductor
totherightFMANT(red)connector.Theshieldisconnected
totheGND(black)connector.
CONNECTINGANAMANTENNA
Ahigh-qualityloopstickantennaisprovided.Itcanbe
rotatedthroughnearly180°inalldirectionsformaximum
performance,optimumsignalreceptionorminimuminter-
ference.Withthismobilityyouwillnotsufferlossofsen-
sitivityregardlessoftheangleatwhichtheinstrumentis
mounted.A backpanelantennajackisprovidedforcon-
nectinganexternalantennaifdesired.
ACPOWEROUTLETS
TherearetwoblackACpoweroutlets,andoneredAC
poweroutlet.TheACpowertotheblackoutletsiscontrolled
bythefrontpanelswitch.Usetheseoutletsfora poweram-
plifier,ortaperecorder,etc.Theredreceptableisonatall
times.Usetheredoutletfora turntableorrecordchanger.
Theturntableisprotectedbythisarrangement.Itisneces-
sarytoturnofftheturntableorrecordchangerwithits
ownACpowerswitch.
GROUNDCONNECTION
Asinglegroundpostisprovided.Groundsforturntables,
recordchangers,tapedecks,etc.shouldbeconnectedto
thispost.Theleftandrightprogramcablesandtheground
wirefromthatsourceshouldbelooselytwistedtogether.
Toavoidhum,makesurethegroundwiredoesnotmake
anycontacttotheshieldsoftheleftandrightprogram
cablesbetweentheprogramsourceandtheMX113.
4

LEFTSPEAKERRIGHTSPEAKER
TO120VACOUTLET
POWER
AMPLIFIER
TURNTABLE
TAPERECORDER
AMANTENNA
FMANTENNA
5

WhattheControlsDoandHowtoUseThem
INPUTSELECTOR
Selectanyoneoffiveprogramsources:
AUX:Connectstheoutputfromanyhighlevelprogram
sourcerequiringflatamplificationtothehighlevel
inputstage.IntheAUXpositionthegainis20dBto
theMAINoutputsand0 dBtotheTAPEoutputs.Thein-
putimpedanceis250,000ohms.
TAPE:Connectstheoutputfroma completetapere-
cordertothehighlevelinputstageoftheMX113.The
TAPEpositionhasflatamplification.Thegainis20dB
totheMAINoutputs.Thegainis0 dBtotheTAPE
outputs.
AM:ConnectstheAMtunerportionoftheMX113to
theoutputjacks.
FM:ConnectstheFMtunerportionoftheMX113to
theoutputjacks.
PHONO1:Connectstheoutputofanymagneticphono
cartridgetothelowlevelinputstage.Theresponseof
thelowlevelstageshasbeenshapedtoconformto
RIAAstandards.Thegamat1000Hzis62dBtothe
MAINoutputs;42dBtotheTAPEoutputs.Theinput
impedanceis47,000ohms.
PHONO2:SameasPHONO1
BASS
TheBASSisa concentriccontrol.Theouterknobcontrols
thelowfrequencyresponseintherightchannel.Thecenter
knobcontrolsthelowfrequencyresponseintheleftchan-
nel.Thetwoknobsarefrictioncoupled.Thispermitsthem
tobeadjustedtogetherorindependently.Clockwiserota-
tionincreaseslowsandcounterclockwisedecreaseslows.
Turnthecontroltothecenterpositionforflatresponse.
TREBLE
TheTREBLEisa concentriccontrol.Theouterknobcon-
trolsthehighfrequencyresponseintherightchannel.The
centerknobcontrolsthehighfrequencyresponseinthe
leftchannel.Thetwoknobsarefrictioncoupled.Thisper-
mitsthemtobeadjustedtogetherorindependently.
Clockwiserotationincreaseshighsandcounterclockwise
decreaseshighs.Turnthecontroltothecenterpositionfor
flatresponse.
BALANCE/LOUDNESS
TheBALANCE/LOUDNESSisa concentriccontrol.The
outerknobcontrolsthebalancebetweenchannels.The
centerknobisa switchthataddsloudnesscompensation
forlowvolumelistening.
BALANCE
TheBALANCEcontroladjustsforunequalvolumein
eithertheleftorrightchannels.Thevolumeofeachchan-
nelcanbevariedrelativetotheotherwithoutaffecting
theircombinedloudness.
LEFT. . . turningthecontroltotheleftaccentstheleft
channelbyreducingtherightchanneloutput
RIGHT. . . turningthecontroltorightaccentstheright
channelbyreducingtheleftchanneloutput.
LOUDNESS
TheLOUDNESScontrolautomaticallyprovidesthecor-
rectamountofbassrequiredtocompensateforthechange
inresponseofthehumanearatlow-loudnesslevels.
Whenthevolumeisreduced,themusicwillseemtolose
muchofitsbassandsomeofitstreble.Thiseffectisdue
tothesensitivitycharacteristicofhumanhearing.There-
sponseofthehumaneartobassandtreblepitchdecreases
6

morerapidlythanitsresponsetopitchcenteredinthemid-
tonalrange.TheLOUDNESSswitchconvertsthevolume
controltoa loudnesscompensatedcontrol.UseLOUDNESS-
INtolistenatlowvolumeandstillhearfull-frequencyrange.
VOLUMEON/OFF
TheVOLUMEcontrolregulatestheloudnessinboth
channels.TheVOLUMEcontrolhasbeenprecisiontracked
throughoutthelisteningrange(0to-65dB)foraccurate
stereobalance.Whenrotatedtothecounterclockwiseposi-
tiontheACpowertotheMX113isturnedoff.
UsingthePushbuttons
MODESELECTOR
Stereo
WiththepushbuttonattheOUTpositiontheleftchannel
isheardfromtheleftloudspeakerandtherightchannelis
heardfromtherightloudspeaker.
Mono(L+ R)
WiththepushbuttonattheINpositiontheleftandright
channelsareaddedtogetherandareheardfromboth
loudspeakers.
LFFILTER
WiththepushbuttonattheINpositionthelowfrequency
responseisattenuatedbelow50Hz.Theslopeis12dB
peroctave.UseoftheLFfilterreducesunwantedlowfre-
quencynoisesuchasrumble.Withthepushbuttonreleased,
theresponseoftheMX113isflat.
HFFILTER
WiththepushbuttonattheINpositionhighfrequency
responseisattenuatedabove5000Hz.Theslopeis12dB
peroctave.UseoftheHFfilterreducesunwantedhighfre-
quencynoiselikehissorscratch.Withthepushbuttonre-
leased,theresponseoftheMX113isflat.
TAPE
TheTAPEpushbuttonallowsinstantaneouscomparison
ofrecordedmaterialandtheprogramsource.Withthepush-
buttonattheINposition,therecordedtapeisheard.With
thepushbuttonattheOUTpositiontheprogrambeing
recordedisheard.
IMPORTANT:WhentheMX113isoperatedwiththe
TAPEpushbuttonattheINposition,signalfromany
othersourcewillnotbeheardfromtheloudspeakers.
Tohearanyotherprogramsource,thepushbuttonmust
beattheOUTposition.
MUTING
MUTINGsuppressesthebackgroundnoiseandhiss
normallyheardbetweenFMstations.Withthepushbutton
attheINpositionthemutingisturnedon.Weakstations
thatmaynotoverridenoiseandinterferencearealsosup-
pressedbythemuting.WiththepushbuttonattheOUT
position,themutingisturnedoff.Thisallowsconventional
FMtuningwiththebetweenstationnoiseandinterference
present.
SELECT
WiththeSELECTpushbuttonattheINpositiontheselec-
tivityoftheMX113isincreasedinbothFMandAM.The
sidesoftheIFcurvearecompressedwhichincreasesthe
abilityofthetunertoseparatea weak(distant)station
froma strong(local)stationonadjacentchannels.
PANLOC
MclntoshdevelopedPANLOCmountingbringsprofes-
sionalinstallationtechniquetostereo.Depressingthe
PANLOCbuttonswilllocktheinstrumentfirmlyinthe
installation.DepressingthePANLOCbuttonsa secondtime
willreleasetheinstrument.Itcanthenbepulledtoward
youtothe"adjustment"position.Inthispositionthetop
panelcontrolscanbeadjusted.
7

BalancingYourStereo
Theperformanceandenjoymentofa stereosystemis
greatlyincreasedwhenthesoundisproperlybalanced.
Thebalanceofthestereosystemisaffectedbymanythings
includingroomacoustics,furnitureplacement,roomshape,
smalldifferencesinloudspeakers,etc.Toassistyouin
balancingyourstereosysteminyourroom,hereisthe
proceduretodeterminecorrectphaseandprogramloudness.
TOADJUSTPHASE
1.Playa familiarrecord.
2.PresstheMODEpushbuttontotheMONOposition.
3.TurnBALANCEcontrolto12o'clockposition.
4.Standabout10feetinfrontofandmidwaybetweenthe
loudspeakers.Thesoundshouldappeartocomefrom
directlyinfrontofyou.Ifthesoundisnotdirectlyin
frontofyouwiththephaseswitchinthe0°NORMAL
position,reversetheleadsononeloudspeaker.When
thesoundcomesfromdirectlyinfrontofyouthe
speakersareinPHASE.UsethePHASEswitchtocorrect
foroutofphaseprogramsources.
TOBALANCELOUDNESS
1.PresstheMODEpushbuttontotheMONOposition.
2.Playa familiarrecording,
3.TurntheBALANCEcontroltothe12o'clockposition.
4.Whiletheprogramisplaying,standbetweenthetwo
loudspeakers.Listenfora differenceinloudnessbe-
tweenspeakers.Balancethesystembyadjustingthe
controlsonthepoweramplifiers.Next,settheMODE
selectortoSTEREO.Ifthereisthena differenceinloud-
nessturntheBALANCEcontroltowardthespeakerthat
isnotasloud.AdjusttheBALANCEcontroluntilthe
soundissatisfactorybetweenbothspeakers.
8