McIntosh MX 114 User manual

PREAMPLIFIER
FMTUNER
STEREO
MX 114
PRICE$1.25

PREAMPLIFIER
FMTUNER
STEREO
I I
MX 114
CONTENTS
GENERALDESCRIPTION2
TECHNICALDESCRIPTION3-5
BLOCKDIAGRAM6
SPECIFICATIONS7
INA HURRY8
CABINETINSTALLATION9
CONNECTIONS10-11
FRONTPANELCONTROLS12-13
BALANCING14
USINGYOURSTEREO15
GUARANTEE16
TheMclntosh"willtoperfection"requiresthatweprobe
constantlyintotheunknowntobringtheperformanceofour
electronicequipmentclosertoperfectionthaneverbefore.
Thisrequiresa constantandrelentlesssearchforlownoise,
broadbandconservativedesignwithaneverlowerdistortion
factor.Thisisnotrequiredofordinaryequipmentofaverage
designs.Itis,forus,a costlybutworthwhilescientificand
engineeringeffort.Ourcontinuingresearchbenefitsourcus-
tomerswiththealmostcompletelackofobsolescenceand
themostreliableequipmentevermade.Italsomeansthe
lowestlong-rangecosttoyou.NearlyalloftheMclntosh
equipmentevermadeisstilluseable,orinuse,thoughit
mayhavebeenmadetwentyyearsago.
Yourpurchaseofa Mclntoshinstrument
showsthatyouarea carefuldiscriminat-
ingbuyer.Onewhoisinterestedinquality
performance,qualityengineering,quality
manufacturing,andlongtrouble-free
equipmentlife.Youcanprotectyourin-
vestmentbyspendinga fewminutesread-
ingthisowner'smanual.
Whenyouboughta Mclntosh,youbought
countlesshoursofmusicalpleasureand
superiorperformance.Enjoyit!
1

GENERALDESCRIPTION
TheMX114combinesinoneunitanex-
tremelylow-distortionpreamplifierwitha
highlysensitiveFMmultiplextuner.The
INPUTSELECTORgivesyoua choiceof
fivedifferentprogramsources.
TheMclntoshMX114isa beautifully
engineeredtuner/controlcenterforthe
fineststereosoundsystems.
TheMX114iscompletelysolidstate,with
theexceptionofthetuningindicator.The
solidstatedevicesusedintheMX114
areproductsofthelatesttechnologyof
solidstatephysics.
Theextremecareinmanufacturing,in
layoutdesignandinqualitycontrolprom-
isestheusualMclntoshextravaluesof
reliability,performance,andlonglife.
Othervaluesaddedtothistunerare:
carefulcontrolofcircuitconstantsdur-
ingtesting,very highsensitivityandex-
cellentspuriousresponserejection.
Everydesirablefeatureofa tunerand
preamplifierisincludedinthisdesign.
FMinterstationnoisesuppression(mut-
ing),tuningindicator,FMmultiplexindi-
cator,individualchannelbassandtreble
controlsandelectronicphaseswitch
haveallbeenengineeredintotheMX114.
TheMclntoshdesignedPANLOCsystem
isthefirstprofessionalinstallationtech-
niquetobeusedonstereoinstruments.
ThePANLOCsystemgivesyoueaseof
installation,operationandmaintenance.
ByreleasingthePANLOCbuttonsonthe
frontpanel,youcanslidetheMX114out
ofitsmountinguntilthesecondlatchen-
gages.Thetopmountedcontrolsfor
interstationnoisesuppression(muting),
phaseswitchingandfrontpanellighting
arenowavailable.
2

TECHNICALDESCRIPTION
FMSECTION:
TheFMconsistsoftwoseparatemodu-
larsections:
ATHERFSECTION:
ThissectionhousesthecompleteFM
front-end.
TheFMcircuitemploysthreejunc-
tionfieldeffecttransistors,twoof
whichformtheveryhighfrequency
amplifierina series-fed"cascode"
typecircuit,givingmaximumgainat
minimumthermalnoise.
ThisVHFamplifierisprecededbya
double-tunedcircuitandisfollowed
bya mixercircuitemployingthethird
junctionfieldeffecttransistoranda
single-tunedcircuit.
TheFMlocaloscillatorisdesigned
forminimumresponsetotempera-
turevariations,makingautomaticfre-
quencycontrolunnecessary.The
driftrateislessthan10partsper
megahertzperdegreecentigrade.
TheRFcircuitsoftheMX114are
completelyshieldedandexceedthe
FCCrequirementsforsuppressionof
oscillatorradiation.
Eithera 300ohmor75ohmantenna
maybeusedwiththeMX114.
AVHFtelevisionantennawhichis
suitableforFMreceptioncanbecon-
nectedtotheMX114.Formaximum
performancewerecommenda good
FMyagiorlog-periodicantennawith
rotator.
BTHEFM-IFANDDETECTOR
SECTION:
Thissectionemploystwointegrated
circuitdevices,eachcapableofam-
plifyingtheintermediatefrequency
signalfromthemixerbya thousand
times(60db).Lumpedselectivityin
theformoftwosetsofquadruple-
tunedbandpassfiltersinsuregood
intermediatefrequencyskirtselectiv-
ity.
Thetunedcircuitsthatmakeupthe
bandpassfiltersaredesigned1or
electricalstabilityandforelectrical
andmechanicalresistancetoshock
andvibration.
"Hard"limitingisaccomplishedby
theuseofthetwointegratedcircuits.
Thelimitingiscompleteatvery low
levelsofinputsignals.
AphaseorFoster-Seeleydiscrimi-
natorisusedastheFMdetector,and
isdesignedforextremelylowhar-
monicdistortionintherecovered
outputsignal.Withthe"Hard"limit-
ingpropertiesoftheprecedingtwo
stagesa lowcaptureratioisobtained.
FMSTEREOMULTIPLEXSECTION:
Themultiplexsectionusesa specialMc-
lntoshdevelopeddetectingcircuit.A par-
ticularadvantageofthiscircuitisthe
eliminationofthecriticaladjustments
necessarywithcommonlyusedmatrix-
ingcircuits.ThiscircuitdetectstheL —R
sidebandsandautomaticallymatrixes
therecoveredinformationwiththeL + R
maincarriersignaltoyieldtheleftand
rightprogramoutputwithmaximumsep-
aration.
The19KCpilotsignalisfilteredfromthe
compositestereoinputsignal,amplified
bya speciallimitingamplifier,doubled
tothe38KCcarrierfrequency,andthen
amplifiedagainbya limitingamplifier.
Thecompositesignalminusthe19KC
pilotiscombinedwiththe38KCcarrier
signalandfedtothespecialdetectorcir-
cuitmentionedabove.Balancedfullwave
detectorsareusedtocancelthe38KC
componentsintheoutput.
Athreesectionphaselinearsharpcutoff
filterrejectsSCAinterferencewithoutde-
stroyingstereoseparation.
FMmuting,automaticFMstereoswitch-
ing,andanFMstereoindicatorarealso
partofthemultiplexsection.TheFM
mutingoperatesbydetectingultra-sonic
noisewhichispresentwhentuningbe-
tweenstationsorwhenreceivinga weak
station.TheFMmutingoperatesequally
well,ofcourse,whenreceivingmonoor
stereostations.TheautomaticFMstereo
switchingactivatesthestereomultiplex
circuitswhenreceivingFMstereo.On
monoFMstationsthiscircuitisinactive
andthereforemaximumsignaltonoise
ratioisassuredatalltimes.
TheFMstereoindicatorislitwhenthe
tuningdialpointercrossesa station
broadcastingFMstereo.Thelightdoes
notindicatewhentuningbetweenthe
stations.
3

TUNINGMECHANISMandDIALDRIVE:
IntheMX114,a newtypeofmechanical
tuningassemblygivessmoothflywheel
tuning.
Bycontrollingtherelationshipofmass
andmechanicalresistance,andbydivid-
ingtheworkloadsinthedialdrivesystem,
itbecomesnearlyimpossibletodetect
anybacklash.Yet,theentiredialdriveis
amodelofmechanicalstability.
Forincreasedtuningaccuracy,a section
ofthedialpointerisilluminated.
4
Therearethreetransistorsineachchan-
nelofthephonopreamplifier.Theoutput
ofthethirdtransistorisconnectedby
anegativefeedbacklooptotheemitter
oftheinputtransistor.Thefeedbackloop
reducesnoiseanddistortion.Italsopro-
videsprecisionRIAAfrequencycompen-
sationrequiredformagneticphonograph
cartridges.Feedbackremainsineffect
evenat20Hz,wheregainishighest.The
negativefeedbackalsoprovidesa low
outputimpedanceforthetapeoutput.
Phonoinputoverloadisvirtuallyimpos-
sible.Forexample,at1000Hz,thephono
inputcanaccept150millivoltsofsignal
withoutoverload.Tenmillivoltsofsignal
atthephonoinputat1000Hzwillpro-
duce1.2voltsatthetapeoutput.More
thanadequateforrecordingontape.
Theselectorswitchconnectseitherthe
outputofthephonoamplifier,theFM
tunersectionora highlevelinputtothe
mainpreamplifier.
Thehighlevelinputimpedanceis250,-
000ohms.Thehighlevelinputfeedsdi-
rectlytothevolumecontrol.A loudness
contourcircuitisconnectedtoa tapon
thevolumecontroltoprovideloudness
compensation.Compensationcanbe
switchedinorout.Thehighlevelsignal
thenfeedstoa pairoftransistorscon-
nectedashighgainamplifiers.
Intheleftchannelthesecondtransistor
isconnectedina balancedoutputar-
rangementallowingtheleftbeinphase
ortobephasereversed.Thiscircuitpro-
videsequalamplitudesignalssothatthe
outputleveldoesnotchangewhenthe
PHONOPREAMPLIFIER

usedaroundthispairoftransistorsto
reducenoiseanddistortion.Thenega-
tivefeedbackprovidesthelowimped-
anceneededtodrivethehighlyselective
filternetworkswhichfollow.
Thefilternetworkscanbeswitchedinor
out.Thehigh-frequencyfilternetworkre-
ducestrebleresponseabove5000Hz.
Thelow-frequencyfilterreducesbassre-
sponsebelow50Hz.Theslopeofthe
filtersisselectedformaximumrejection
ofcommonlyencounterednoise.Careful
designkeepsthelossofusableprogram
materialtoa minimum.
Theoutputfromthefiltercircuitsisfed
intothebalancecontrol.Theoutputof
thebalancecontroldrivesthefirststage
ofthetonecontrolsection.Theremain-
ingtwotransistorsareconnectedasa
high-gainamplifierstage.Thehigh-gain
ofthisstageisusedtoadvantageforthe
tonecontrolnegativefeedbackcircuits.
Negativefeedbackinthetonecontrol
circuitsassureslowdistortionandaccu-
rateshapeonthetone-controlresponse
curves.Negativefeedbackismaintained
atallfrequencies,evenwiththetonecon-
trolsturnedtofullboost.Overalldistor-
tionislowatallfrequenciesincluding
frequencieswheremaximumboostoc-
curs.Thenegativefeedbackalsopro-
videsthelowimpedanceoutputrequired
forthemainpreamplifieroutputs.
CENTERCHANNELAMPLIFIER
TheL + R amplifierconsistsofa single
transistorconnectedasa voltageam-
plifier.Negativefeedbackisused
aroundthevoltageamplifiertomain-
tainlowdistortionandprovidea low
impedanceforthecenterchannel
output.
POWERSUPPLY:
ThepowersupplyoftheMX114has
receivedveryspecialdesignatten-
tion.
Twoseparaterectifiercircuitsare
used.First,a full-waverectifiersup-
pliesD.C.toallaudiocircuits.The
secondfull-waverectifiersupplies
D.C.toalltunerandmultiplex-de-
codercircuits.
Bothpowersuppliesarevery elabor-
ateindesign.Speciallyselectedtran-
sistorsandtheirassociatedcircuits
havebeendesignedtoformtwovolt-
ageregulators.Theregulatorsuse
electronicfilteringtoinsurethelow-
estpossiblebackgroundhumlevel,
maximumstability,andextremely
goodregulation.
MX 114
55

BLOCKDIAGRAM
6
PREAMPLIFIERSECTION
TUNERSECTION
POWERSUPPLY

FM
USABLESENSITIVITY:Betterthan2.5microvoltsat100%
modulation(±75kHzdeviation)forless than3%total
noiseandharmonicdistortion(IHF)
FREQUENCYRESPONSE:±1dB(fom20Hzto20,000Hz
withstandardde-emphasisand19,000Hzpilotfilter
HARMONICDISTORTION:Mono,less than0.5%at100%
modulation±75kHzdeviation
IMAGEREJECTION:Betterthan80dBat100MHzbetter
than70dBat105MHz
SPURIOUSREJECTION;Betterthan100dB
CAPTURERATIO:Betterthan1.8dB
DRIFT:Lessthan25,000Hz
HUMANDNOISE:Betterthan65dbbelow100%modu-
lation
TUNINGINDICATOR:ElectronRayforsimpleaccurate
centerofchanneltuning
STEREOINDICATOR:Stereolightactivatedby19kHz
carrieronly
PREAMPLIFIERSPECIFICATIONS
FREQUENCYRESPONSE:±0.5db20to20,000Hz
DISTORTION:Lessthan0.1%at2.5voltsoutput,20to
20,000HZ
INPUTSENSITIVITYANDIMPEDANCE:PHONO1 and
PHONO2:2 millivoltsat47,000ohmsfor2.5volts
output
AUXTAPE:.25voltsat250,000ohmsfor2.5volts
output
HUMANDNOISE:PHONO1 andPHONO2:70dBbelow
10millivoltinput:equivalenttoless than3 microvolts
attheinputterminals
AUX-TAPE:85dBbelowratedoutput
OUTPUT:MAIN:2.5voltswithratedinput.Upto10volts
canbedevelopedwithoutdistortion
SPECIFICATIONS
TAPE:2.5voltswithratedinput
L+Ft:2.0voltswithratedInput
OUTPUTIMPEDANCE:MAIN:200 ohms,designedto
operateinto47,000ohmsormore
TAPEOUTPUT:About200ohms,designedtooperate
into47,000ohmsormore
(L+ R):About1,200ohms,designedtooperateinto
47,000ohmsormore
SEMICONDUCTORCOMPLEMENT:
3FieldEffectTransistors
26SiliconPlanarTransistors
3IntegratedCircuitsandMonolithicAmplifier
13SignalDiodes
2ZenerDiodes
4Rectifiers
1TuningIndicator— 6HU6
POWERREQUIREMENTS:117/125volts,50.60Hz,30
watts.
MECHANICALSPECIFICATIONS
SIZE:Frontpanel:16incheswideby51/16incheshigh:
Chassis:15incheswideby13inchesdeep,including
PANLOCshelfandbackpanelconnectors;KnobClear-
ance:1½Inchesinfrontofmountingpanel
WEIGHT:24poundsnet,36poundsinshippingcarton
FINISH:Frontpanel:Anodizedgoldandblackwithspecial
gold/tealpanelnomenclatureillumination
CHASSIS:Chromeandblack
MOUNTING:MclntoshdevelopedprofessionalPANLOC
FACILITIES
BASSCONTROL:-20dBto+ 16dBat20Hz.Clutch
coupledcontrolsforindependentadjustmentofeach
channel
TREBLECONTROLS:±20dBat20,000Hz.Clutch
coupledcontrolsforindependentadjustmentofeach
channel
LOUDNESS:Flatresponse,orcompensatedforlowlisten-
inglevels
BALANCE:Whenprogrammaterialisoutofbalance,ro-
tationofthebalancecontrolreturnstheprogramto
naturalbalance
VOLUMECONTROL:Precision"tracked"to—60dBso
thatproperstereobalanceismaintained.ACON/OFF
switchiscoupledwiththevolumecontrol
TAPEMONITORSWITCH:Pushbutton;comparesre-
cordedtapewithprogramsourcewhilerecording
VOLTAGEAMPLIFICATION:
AUX,TAPE
ToMAINoutput20dB
ToTAPEoutput0 dB
PHONO1,PHONO2
ToMAINoutput62dB
ToTAPEoutput42dB
ACOUTLETS:
1unswitched(Red)
2switched
LFFILTER:Flat,orroll-offbelow50Hz,6 dBperoctave,
down12dBat20Hz
HFFILTER:Flat,orroll-offabove5 kHz,6 dBperoctave,
down12dBat20,000Hz
INPUTSELECTOR:6 positions:AUX(auxiliaryorspare),
TAPE.AM,FM,PHONO1,andPHONO2
MODESELECTOR:Pushbutton,STEREO,orMONO
SECONDARYCONTROLS
PHASECONTROL:Electronicallyreversephaseintheleft
channeltocorrect"outofphase"programsources
MUTINGADJUST:Modifiesthenoiserejectionthreshold
DIALSCALEINTENSITY;Modifiesthebritenessofthe
illuminationofthefrontpanel
7

INPUTSELECTOR
AUX:Anyprogramsourcerequiringflatamplification
isconnectedtotheAUXjacksonthebackpanel.
TAPE:Theoutputofa taperecorderwithitsown
electronicsisconnectedtotheTAPEjacksonthe
backpanel.
FM:ForlisteningtotheFMsectionoftheMX114.
PHONO1:Theoutputofa recordplayerorturntable
isconnectedtothePHONO1 jacksontheback
panel.
PHONO2:Theoutputofanotherrecordplayeror
turntableisconnectedtothePHONO2 jackson
thebackpanel.
TREBLE:Modifiesthehighfrequencyprogramma-
terialtosuityourtaste.Therightchannelisthe
largeknob,theleftchannelisthesmallknob.
BASS:Modifiesthelowfrequencyprogrammaterial
tosuityourtaste.Therightchannelisthelarge
knob,theleftchannelisthesmallknob.
BALANCE:Adjustsforequalloudnessineachchan-
nelwhentheprogramsourcehasunequalchannel-
to-channelvolume.
VOLUMEON/OFF:TurnstheMX114"ON"andad-
justsloudnessofthesound.
PUSHBUTTONS:
MODESELECTOR:PushINforMONO;OUTfor
STEREO.
HF:PushIN:Reduceshighfrequenciestosup-
pressunwantedrecordnoise,etc.;OUT:Flat
response.
LF:PushIN:Reduceslowfrequenciestosuppress
unwantedrumble;OUT:Flatresponse.
TAPE:PushIN:Monitortherecordedprogram
fromthetape.PushOUT:Heartheprogramthat
isbeingrecorded.
MUTING:intheINpositionthemutingisturnedon.
Weakstationsthatmaynotoverridenoiseand
interferencearesuppressedbythemutingtothe
OUTposition,themutingisturnedoff.Thisallows
conventionalFMtuningwiththenoiseandinter-
ferencepresent.Usethispositiontotuneweak
ornoisystations.
LOUDNESS:PushIN:Adjustsbassasvolumeisre-
ducedtocompensateforaveragehearinglosses
atlowvolume.
8
IFYOU'REINA HURRY

INSTALLATIONINA CABINET
TopreparetheMX114(orinstallationremovethe
plasticprotectivecovering.TurntheMX114upside
downsothatitrestsonitstopontheshippingpallet.
Removethetourplasticfeetfastenedtothebottom
ofthechassis.
Nextplacethemountingbrackets,thepartsbagand
themountingtemplateforeasyaccessibility.
Theprofessionalmountingdesigneliminatestheneed
foranyshelforbrackettosupporttheMX114.Itis
completelysupportedbyitsownmountingbrackets.
Positiontheplasticmountingtemplateoverthearea
ofthecabinetpaneltobecutoutforinstallation.
Thedesignofthemountingtemplateallowsyouto
positionorlocatethecutoutfromthefrontorrearof
thepaneltowhichtheinstrumentistobemounted.
Ifthecutoutistobelocatedfromtherearofthepanel.
thefollowingstepswillhelpyou.
Onthebackofthecabinetpanel,scribea vertical
centerlinethroughtheexactcenteroftheareainwhich
thecutoutistobemade.
Placethetemplateagainstthebackofthepaneland
matchthetemplatecenterlinewiththecenterlineonthe
cabinetpanel.
Makesurethatthereisatleast¼ inchclearancebe-
tweenthebottomofthedashedlineofthecutoutarea
onthetemplateandanyshelforbracebelowthepro-
posedcutout.
Markthetwolocatingholes("C"holesonthemount-
ingtemplate).
Drillthetwolocatingholes.Becertainthedrillisper-
pendiculartothepanel.
Nowpositionthetemplateonthefrontofthepanelby
aligningthe"C"locatingholesonthetemplatewith
thedrillholes.
Securethemountingstripstotherearofthecabinet
panelusingtwoscrewsfromthehardwarepackage.
Attachthemountingbracketstothecabinetpanelus-
ingfourscrews.
Placethetemplateoverthemountingscrews.The
mountingscrewsshouldbecenteredinthe"A"and
'B"holesonthetemplate.Thesidesofthemounting
bracketsshouldmatchtheverticaldashlinesonthe
template.Ifnecessary,loosenthescrewsandpushthe
bracketsintoalignmentandretighten.
Insertthepowercordthroughtheopening.Carefully
slidetheMX114intotheopeningsotherailson
thebottomoftheequipmentslideinthetrackofthe
mountingbrackets.Continuetoslidetheinstrumentin
untilthefrontpanelisagainstthecabinetpanel.
AtthebottomfrontcornersofthePANLOCinstruments
arethePANLOCbuttons.
Aftera PANLOCInstrumenthasbeeninstalled,de-
pressingthePANLOCbuttonswilllocktheinstrument
firmlyintheinstallation.DepressingthePANLOCbut-
ona secondtime(aswitha ball-pointpen)willrelease
theinstrument.Youcanthenslidetheinstrumentfor-
wardtotheinspection-adjustmentposition.
DepressingtheInspection-adjustmentpositionlatches
willallowtheinstrumenttobeslidcompletelyoutof
theinstallation.
VERTICALINSTALLATION
Inthehardwarepacketaretwohelicalsprings.Fasten
thespringstothesmallflangesattherearofthe
PANLOCbrackets.Theflangehasa notchanda hole
tomountthespring.ThespringsassistIntheremoval
ofverticallymountedPANLOCequipment.
DONOTUSETHESPRINGSONHORIZONTALLYMOUNTEDEQUIPMENT. 9
Insertthescrewsinthecenterholesofthecabinet
panel("B"holesonthetemplate)andtighten.The
screwheadshouldpullintothewoodslightly.(Usetwo
¾inchlongscrewsforpanelsunder½ inch,ortwo1¼
inchlongscrewsforpanelsViinchthickandlarger.)
Withthetemplateinplaceagainstthecabinetpanel,
markthe"A"and"B"drillholesandthefoursmall
holesthatidentifycornersofthecutout.Jointhecorner
markswitha pencil.Theedgeofthetemplatecanbe
usedasa straightedge.
IMPORTANT:DRILLTHE6 HOLESBEFOREMAKING
THECUTOUT
Accuratelydrillthethreeholesoneachsideofthecut-
outareawitha 3/16Inchdrill.
WiththesawontheINSIDEOFTHEPENCILLINES
carefullycutouttherectangularopening.

CONNECTINGTHEMX114
CONNECTINGA RECORDPLAYERTO
PHONO1
Connectthe"left"channeltothe"up-
per"PH1 inputjack.
Connectthe"right"channeltothe
"lower"PH1 inputjack.
PHONO2 positionisusediftworec-
ordplayersareusedina system.Con-
nectthe"left"channeltothe"upper"
PH2 inputjack.Connectthe"right"
channeltothe"lower"PH2 inputjack.
CONNECTINGA TAPERECORDERTO
RECORD
ConnecttheMX114outputjacks
markedTAPEtothehighlevelinputs
ofthetaperecorder.
CONNECTINGA TAPERECORDERFOR
PLAYBACK
Connectthe"left"channelrecorder
outputtothe"upper"TAPE1 input
jack.
Connectthe"right"channelrecorder
outputtothe"lower"TAPE1 input
jack.
CONNECTINGTHEMX114TOPOWER
AMPLIFIERS
Connecttheoutputjacksmarked
MAINtotheinputofa stereopower
amplifier.Theupperjackisconnected
totheLEFTamplifierinputjack.The
lowerjackisconnectedtotheright
amplifierinputjack.
TheoutputimpedanceattheMAINout-
putis200ohms.Longercablesthan
arenormallysuppliedcanbecon-
nectedbetweentheMX114andthe
amplifiers.Thelengthofthecableis
limitedbythecapacityofthecable.
Thetotalcapacitymustnotexceed
1000pF.Forinstance:cableswitha
capacityof25pFperfootmaybe40
feetlong;13.5pFperfootcablemay
be75feetlong.Theinputimpedance
oftheamplifiersshouldbe47,000ohms
orgreater.
CONNECTINGANFMANTENNA
Monophonicinstallationsthataresat-
isfactoryonanindoorantennamay
requiretheuseofanoutdoorantenna
forequivalentresults.Satisfactory
stereorequiresabout10timesas
muchsignalfromtheantenna.
WiththeMX114oneofthreean-
tennasystemscanbeused:(1)thein-
doordipolesuppliedwiththeMX112,
(2)anoutdoorFMantenna,or(3)a
VHF-TVantenna.Infringeareasbest
resultswillprobablybeobtainedwith
theuseofanoutdoorFMantenna.In
manyareastheindoordipoleantenna
maybesatisfactory.Theuseofa VHF-
TVantennaisalsoeffectiveinmany
installations.
CONNECTINGANINDOORDIPOLE
ANTENNA
Theflexiblefoldeddipoleantenna(300
ohm)suppliedwiththeMX114isfor
indooruseinurbanorhighstrength
signalareas.
Connectthetwoleadsfromthedipole
totheterminalsmarkedFMANT(red).
Theflexibilityofthethinflatwireas-
semblypermitsittobeplacedundera
rug,tackedbehindthestereo...or,
placedinanyotherconvenientloca-
tion.Insomecases,itmaybeneces-
saryto"position"theantennaforbest
signalreception.Thisshouldbedone
beforeitispermanentlylocatedor
tackeddown.
CONNECTINGANOUTDOORFM
ANTENNA
Anoutdoorantennaisrecommended
foroptimumperformanceinallareas.
Infringe(outlying)areas,bestresults
willbeobtainedwitha highlydirec-
tionalFMantennausedinconjunction
witha rotator.Rotatetheantennaun-
tilthebestreceptionisobtained.Con-
nectthe300ohmantennatothetermi-
nalsmarkedFMANT(red).
CONNECTINGA 75OHMCOAXIAL
ANTENNA
Anunbalanced75ohmantennacanbe
connectedtotheMX114withcoaxial
cable.Connectthecenterconductor
totheleftFMANT(Red)connector.
TheshieldisconnectedtotheGND
(black)connector.
TheMclntoshdesignedbalunmatches
the75ohminputtothetunerforopti-
mumperformance.
ACOUTLETS
Thereare2 blackACoutletsandone
redACoutlet.Thepowertotheblack
ACoutletsiscontrolledbythefront
panelswitch.Usetheseoutletsfora
tuner,taperecorder,etc.Theredre-
cepticleisonatalltimes.Usethered
outletfora turntableorrecordchanger.
Theturntableisprotectedbythisar-
rangement.Itisnecessarytoturnoff
theturntableorrecordchangerwith
itsownACswitch.

CONNECTINGTHEMX114
11

USINGTHEFRONTPANELCONTROLS
INPUTSELECTOR
INPUTSELECTOR:Selectsanyoneof
sixprogramsources:
AUX:Anyhighlevelprogramsourcere-
quiringflatamplification,suchasa tele-
visionset,isconnectedtotheinputstage
oftheMX114intheAUXposition.The
gainis20dBtotheMAINoutputs.The
gainis0 dBtotheTAPEoutputs.
TAPE:Anyself-containedtapemachine
(tapemachinehavingitsownplayback
preamplifier)isconnectedtothehigh
levelinputstageoftheMX114inthe
TAPEposition.Hasflatamplification.The
gainis20dBtotheMAINoutputs.The
gainis0 dBtotheTAPEoutputs.
FM:ConnectstheFMtunerportionofthe
MX114totheoutputjacks.
PHONO1:Connectsthebackpaneljacks
(PH1)totheMX114.Theamplification
hasbeencompensatedformagnetic
phonocartridges.Thegainis62dBto
theMAINoutputsand42dBtotheTAPE
outputs.Theinputimpedanceis47,000
ohms.
PHONO2:Connectsthebackpaneljacks
(PH2)totheMX114.Theamplification
hasbeencompensatedformagnetic
phonocartridges.Thegainis62dBto
theMAINoutputand42dBtotheTAPE
outputs.Theinputimpedanceis47,000
ohms.
BASS
TheBASSisa concentriccontrol.The
largeouterknobcontrolsthelowfre-
quencyresponseintherightchannel.
Thesmallcenterknobcontrolsthelow
frequencyresponseintheleftchannel.
Thetwoknobsarefrictioncoupled.This
permitsthem tobeadjustedtogetheror
independently.Clockwiserotationin-
creaseslowsandcounterclockwisede-
creaseslows.Positionthecontroltothe
centerpositionforflatresponse.
TREBLE
TheTREBLEisa concentriccontrol.The
outerknobcontrolsthehighfrequency
responseintherightchannel.Thesmall
centerknobcontrolsthehighfrequency
responseintheleftchannel.Thetwo
knobsarefrictioncoupled.Thispermits
themtobeadjustedtogetherorinde-
pendently.Clockwiserotationincreases
highsandcounterclockwisedecreases
highs.Flatisthecenterposition.
BALANCE
TheBALANCEcontroladjustsforun-
equalvolumeineithertheleftorright
channels.Thevolumeofeachchannel
canbevariedrelativetoeachotherwith-
outaffectingtheircombinedloudness
LEFT. . . turningthecontroltotheleft
accentstheleftchannelbyreducingthe
rightchanneloutput.
RIGHT. ..turningthecontroltotheright
accentstherightchannelbyreducing
theleftchanneloutput.
VOLUMEON/OFF
TurningtheVOLUMEtotallycounter-
clockwiseturnstheMX114OFF.The
VOLUMEcontrolregulatestheloudness
inbothchannels.TheVOLUMEcontrol
hasbeenprecisiontrackedthroughout
thelisteningrange(0to-65dB)foracccu-
ratestereobalance.
12

PUSHBUTTONS
MODESELECTOR:STEREO:Theleft
channelisheardfromtheleftloud-
speakerandtherightchannelisheard
fromtherightloudspeaker.
MONO(L+ R):Theleftandrightchan-
nelsareaddedtogetherandareheard
frombothloudspeakers.
LFFILTER:Withthepushbuttonpushed
inthelowfrequencyresponseisattenu-
atedbelow50Hz.Theslopeis6 dBper
octave.UseoftheLFfilterreducesun-
wantedlowfrequencynoisesuchas
rumble.Withthepushbuttonreleased,
theresponseoftheMX114isflat.
HFFILTER:Withthepushbuttonpushed
INthehighfrequencyresponseisattenu-
atedabove5 kHz.Theslopeis6 dBper
octave.UseoftheHFfilterreducesun-
wantedhighfrequencynoiselikehissor
scratch.Withpushbuttonreleased,the
responseoftheMX114isflat
TAPE:TheTAPEpushbuttonisusedto
monitortapeasitisbeingrecorded.With
thepushbuttonIN,therecordedtapeis
heard.Releasethebuttonandthepro-
grambeingrecordedisheard.Instan-
taneouscomparisonofrecordedmaterial
andtheprogramsourceisprovidedby
theuseoftheTAPEpushbutton.
IMPORTANT:WhentheMX114isoper-
atedwiththeTAPEpushbuttoninthe
INposition,signalfromanyothersource
willnotbeheardfromtheloudspeakers.
Whennotinusemakesurethepushbut-
tonisinthe"OUT"position.
MUTING:Mutingsuppressestheback-
groundnoiseandhissnormallyheard
betweenstations.Withthecontrolinthe
INpositionthemutingisturnedon.Weak
stationsthatmaynotoverridenoiseand
interferencearealsosuppressedbythe
muting.IntheOUTposition,themuting
isfumedoff.Thisallowsconventional
FMtuningwiththenoiseandinterfer-
encepresent.Usethispositiontotune
weakornoisystations.
LOUD:Whenthevolumeisreduced,the
musicwillseemtolosemuchofitsbass
andsomeofitstreble.Thiseffectisdue
tothesensitivitycharacteristicofhuman
hearing.Theresponseofthehumanear
tobassandtreblepitchdecreasesmore
rapidlythanitsresponsetonotescen-
teredinthemid-tonalrange.TheLOUD
controlautomaticallyprovidesthecor-
rectamountofbassandtrebleboostre-
quiredtocompensateforthischangein
responseofthehumanearatlow-loud-
nesslevels.TheLOUDconvertsthevol-
umecontroltoa loudnesscompensated
control.UsetheLOUDINtolistenatlow
volumeandstillhearfull-frequency
range.
PANLOC
MclntoshdevelopedPANLOCmounting
bringsprofessionalinstallationtech-
niquetostereo.DepressingthePANLOC
buttons(aswitha ballpointpen)will
releasetheinstrument.Itcanthenbeslid
forwardtothe"adjustment"position.In
the"adjust"positionthetoppanelcon-
trolsPHASE,MUTINGandDIALSCALE
INTENSITYcanbeadjusted.
13

BALANCINGYOURSTEREO
Theperformanceandenjoymentofa stereosystem
isgreatlyincreasedwhenthesystemisproperly
balanced.Threeofthefactorsthateffectproper
stereobalanceare:
1.Balanceoftheentiresystem.
2.Properphaseinbothchannels.
3.Equalprogramloudness.
SYSTEMBALANCE
Thebalanceofthestereosystemisaffectedby
manythingsincludingroomacoustics,furni-
tureplacement,roomshape,smalldifferences
inloudspeakers,etc.
TOADJUSTPHASE
1.SettheMODEswitchtoMONO.
2.Standabout10feetinfrontofandmidway
betweentheloudspeakers.Thesound
shouldappeartocomefromdirectlyinfront
ofyou.HavesomeoneswitchthePHASE
switch.Ifthesoundisnotdirectlyinfrontof
youwiththePHASEswitchinthe0 NOR-
MALposition,reversetheleadsonone
loudspeaker.Whenthesoundcomesfrom
themidpointbetweenthespeakerstheyare
inPHASE.
TOBALANCELOUDNESS
1.SettheMODEtoMONO.
2.Playa familiarrecording.
3.TurntheBALANCEcontroltothe12o'clock
position.
4.Whiletheprogramisplaying,standbetweenthe
twoloudspeakers.Listentoseeifthereisa dif-
ferenceinloudnessfromeitherspeaker.Bal-
ancethesystembyadjustingthecontrolson
thepoweramplifiers.Next,settheMODEse-
lectortoSTEREO.Ifthereisthena difference,
turntheBALANCEcontroltowardthespeaker
thatisnotasloud.Dothisuntilyoufindthat
pointwherethesoundisequallyloudfromboth
speakers.
14

USINGYOUR
LISTENINGTOA STEREORECORD
1.TurntheINPUTSELECTORtoPHONO1 or
PHONO2.whicheverisconnectedtotherecord
playeryouwishtohear.
2.MakecertaintheMODEPUSHBUTTONisinthe
OUTorSTEREOposition.
3.AdjusttheVOLUMEcontroltodesiredvolume.
LISTENINGTOA MONOPHONICRECORD
1.TurntheINPUTSELECTORtoPHONO1 or
PHONO2,whicheverisconnectedtotherecord
playeryouwishtohear.
2.PushtheMODEpushbuttonINtoMONO.
3.AdjusttheVOLUMEcontroltodesiredvolume.
LISTENINGTOA STEREOTAPERECORDER
TheTAPEinputisused:
1.TurntheINPUTSELECTORtoTAPE.
2.SettheMODEpushbuttontoSTEREOorMONO,
dependingontheprogramonthetape.
3.AdjusttheVOLUMEcontroltodesiredvolume.
Tomonitorwhilerecording,thetaperecorder
musthaveseparaterecordandplaybackheads.
TheTAPEpushbuttonpermitsmonitoringthe
taperecordingswhileintheprocessofrecord-
ing.WhentheTAPEpushbuttonisintheIN
positionitwillplaythesoundfromthetapeasit
passestheplaybackhead,a momentafteritis
recorded.Therecordingprocesscontinuesas
usual.WhentheTAPEpushbuttonisintheOUT
positiontheprogrambeingrecordedisheard.
LISTENINGTOFMorFMSTEREO
1.TurntheINPUTSELECTORtoFM.
2.Adjustthevolumetoa comfortablelevel.
3.Rotatethetuningknobtothestationofyour
choice.
TheMX114usesa newMclntoshdevel-
opedautomaticmono-stereoswitchingcir-
cuit.Theswitchingiselectronicwithout
switchingclicksortransients.
Thecircuitswitchessmoothlyandsilently
whenthe19KCmultiplexcarrierispresent.
WhentheSTEREOindicatorislit,thesta-
tionisbroadcastinga 19KCcarrier.This
signalcausestheautomaticcircuitto
switchtheMX114tostereo.Ifa station
isbroadcastingmonophonicFMprogram,
theSTEREOindicatorwillremainoffand
thetunerwillautomaticallyswitchto
mono.Theultrasonicmutingcircuitsup-
pressesallnoisebetweenstations.Itsup-
pressesallweakerstationsnotstrong
enoughtooverridethebackgroundnoise.
Themutingthresholdsettingdetermines
thestrengthofthesignalwhichcanbe
heardwithmutinginoperation.Themuting
thresholdiscarefullyadjustedtooptimum
atthefactory.Casualadjustmentofthe
mutingthresholdisnotrecommended.
Whiletuningyoumaynoticethatthetun-
ingindicatorwillshowa stationyetnopro-
gramisheardfromthespeakers.Themut-
ingcircuitinthetunerisrejectingthesta-
tionbecausethereisobjectionablenoise
withtheweaksignalfromthestation.Push
theMUTINGpushbuttontotheOUTposi-
tionandthestationwillbeheard.Most
programsthatcanbetunedinthismanner
areofpoorqualityduetointerferingnoise.
15
USINGYOURSTEREO

YourMX114stereopreamplifierFMtunerwillgiveyoumanyyearsof
pleasantandsatisfactoryperformance.Ifyouhaveanyquestionsconcern-
ingoperationormaintenancepleasecontactthedealerfromwhomyou
purchasedthisinstrumentor:—
GUARANTEE
MclntoshLaboratoryIncorporatedguaranteesthisequipmenttobe
capableofperformanceasadvertised.Wealsoguaranteetheme-
chanicalandelectricalworkmanshipandcomponentsofthisequip-
menttobefreeofdefectsfora periodof90daysfromdateof
purchase.Thisguaranteedoesnotextendtocomponentsdamaged
byimproperusenordoesitextendtotransportationtoandfrom
thefactory.
3YEARFACTORYSERVICECONTRACT
Anapplicationfora FREE3 YEARFACTORYSERVICECONTRACT
isincludedinthepackwiththismanual.TheFREE3 YEARFAC-
TORYSERVICECONTRACTwillbeissuedbyMclntoshLaboratory
uponreceiptofthecompletelyfilledoutapplicationform.Theterms
ofthecontractare:
1.Transportationchargesareexcluded.
2.Thisagreementisgiventotheoriginalpurchaseronlyandis
nottransferable.
3.Theapplicationforthecontractmustbefilledoutcompletely.
4.Iftheinstrumenthasbeenmodifiedordamagedbyunauthor-
izedrepairthecontractwillbecancelled.
5.Toreceivefreeservice,thecontractmustbepresentedtothe
factoryauthorizedserviceagency,whentheequipmentispre-
sentedforrepair.
IftheapplicationisnotreceivedatMclntoshLaboratory,onlythe
serviceofferedunderthestandard90dayguaranteewillapplyon
thisequipment.
16
TAKEADVANTAGEOF3 YEARSOFFREEFACTORY
SERVICEBYFILLINGINTHEAPPLICATIONNOW
CUSTOMERSERVICE
MclntoshLaboratoryInc.
2ChambersStreet
Binghamton,N.Y.13903
Ourtelephonenumberis
607-723-3512
MX 114

MclNTOSHLABORATORYINC.
2CHAMBERSST.,BINGHAMTON,N.Y.13903
607-723-3512
Designsubjecttochangewithoutnotice.
PrintedInU.S.A.
038-318