McIntosh MA6200 User manual

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THEMA 6200 INTEGRATEDAMPLIFIER

VARIOUSREGULATORYAGENCIESREQUIRETHATWEBRINGTHEFOLLOWINGINFOR-
MATIONTOYOURATTENTION.PLEASEREADITCAREFULLY.
WARNING:TOPREVENTFIREORSHOCK
HAZARD,DONOTEXPOSETHISUNITTO
RAINORMOISTURE.
TheMclntoshyouhavepurchasedisa ModelMA
6200.Ithasa serialnumberlocatedontherearpanel
ofthechassis.Recordthatserialnumberhere:
SerialNumber
Themodel,serialnumberandpurchasedateare
importanttoyouforanyfutureservice.Recordthe
purchasedatehere:
PurchaseDate
Uponapplication,MclntoshLaboratoryprovidesa
Three-YearServiceContract.YourMclntosh
authorizedServiceAgencycanexpediterepairs
whenyouprovidetheServiceContractwiththein-
strumentforrepair.Toassist,recordyourService
Contractnumberhere:
ServiceContractNumber

YourMA6200IntegratedAmplifier
willgiveyoumanyyearsofpleasantand
satisfactoryperformance.Ifyou
haveanyquestions,pleasecontact:
CUSTOMERSERVICE
MclntoshLaboratoryInc.
2ChambersStreet
Binghamton,NewYork13903-9990
Phone:[phone]
TakeAdvantageof3 years
ofContractService...
FillintheApplicationNOW.
Contents
HOWTOINSTALL...2
HOWTOCONNECT...4
THEFRONTPANELCONTROLS
ANDHOWTOUSETHEM...8
PERFORMANCELIMITS. . .12
PERFORMANCECHARTS. . .13,14
TECHNICALDESCRIPTION...15
BLOCKDIAGRAM...17
MclNTOSHTHREEYEARSERVICECONTRACT
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 Mclntosh
authorizedserviceagency.Iftheinstru-
mentismodifiedordamagedasa result
ofunauthorizedrepair,theSERVICE
CONTRACTwillbecancelled.Damage
byimproperuseormishandlingisnot
coveredbytheSERVICECONTRACT.
4.TheSERVICECONTRACTisissuedto
youastheoriginalpurchaser.Toprotect
youfrommisrepresentation,thiscon-
tractcannotbetransferredtoa second
owner.
5.ToreceivetheSERVICECONTRACT,
yourpurchasemustbemadefroma
Mclntoshfranchiseddealer.
6.Yourcompletelyfilledinapplicationfor
SERVICECONTRACTmustbepostmark-
edwithin30daysofthedateofpurchase
oftheinstrument.
7.ToreceivetheSERVICECONTRACT,all
informationontheapplicationmustbe
filledin.TheSERVICECONTRACTwill
beissuedwhenthecompletelyfilledin
applicationisreceivedbyMclntosh
LaboratoryInc.inBinghamton,NewYork.
Copyright1979© byMclntoshLaboratoryInc.
1

ThePANLOCsystemofinstallingequipmentcon-
venientlyandsecurelyisa productofMclntosh
research.BydepressingthetwoPANLOCbuttons
onthefrontpanel,theinstrumentslidecanbelock-
edfirmlyinplaceoritcanbeunlockedsothatthe
chassiscanslideforward,givingyoueasyaccessto
thetopandrearpanels.
Thetrouble-freelifeofanelectronicinstrumentis
greatlyextendedbyprovidingsufficientventilation
topreventthebuildupofhighinternaltemperatures
thatcausedeterioration.Allowenoughclearanceso
thatcoolaircanenteratthebottomofthecabinet
andbeventedfromthetop.Withadequateventila-
tiontheinstrumentcanbemountedinanyposition.
Therecommendedminimumspaceforinstallation
is15inches(38.1cm)deep,17inches(43.2cm)wide,
and6 inches(15.2cm)high.
Toinstalltheinstrumentina Mclntoshcabinet,
followtheinstructionsthatareenclosedwiththe
cabinet.Foranyothertypeofinstallationfollow
theseinstructions:
1.OpenthecartonandremovethePANLOC
brackets,hardwarepackage,andmounting
templatefromthecarton.RemovetheMA6200from
itsplasticbagandplaceitupsidedownontheship-
pingpallet;unscrewthefourplasticfeetfromthe
bottomofthechassis.
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 3/16inchbitheldperpendicularto
thepanelanddrillthesixA andB holes.Then,using
adrillbitslightlywiderthanthetipofyoursaw
blade,drilloneholeateachoftwodiagonallyop-
positecorners.Theholesshouldbarelytouchthein-
sideedgeofthepenciledoutline.Beforetakingthe
nextstep,makesurethatthesixA andB holeshave
beendrilled.
4.SawthePanelCutout
Sawcarefullyontheinsideofthepenciledlines.
Firstmakethetwolongcutsandthenthetwoshort
cuts.Aftertherectangularopeninghasbeencutout,
usea filetosquarethecornersandsmoothanyir-
regularitiesinthecutedges.
2

5.InstallMountingStrips
Inthehardwarepackageyouwillfindtwomounting
stripsandtwosetsofmachinescrews.Forpanels
thatarelessthan½ inchthick,usethe¾ inch
screws;forpanelsthataremorethan½ inchthick,
usethe1¼inchscrews.
Startingattheright-handsideofthepanel,insert
ascrewoftheproperlengthintothecenterholein
thepanel,markedB onthetemplate.Onthebackof
thepanel,aligna mountingstripwiththeholesin
thepanelandtightenthescrewuntilthescrewhead
ispulledintothewood.
Repeatthisproceduretoattachthemounting
striptotheleftsideofthepanel.
6.AttachPANLOCBrackets
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
theadjustpositionlatches.Pressthelatchesin-
ward,thispermitstheinstrumenttoslideintothe
cabinetuntilitsfrontpanelisflushwiththecabinet
panel.DepressthePANLOCbuttonsatthelowerleft
andrightcornersoftheinstrumentpaneltolockthe
unitfirmlyinthecabinet.DepressingthePANLOC
buttonsagainwillunlocktheinstrumentsothatit
canslideforwardtotheadjustposition;ifyoupress
inwardontheadjustpositionlatchesthenyoucan
removetheinstrumentfromthecabinet.
3

HowtoConnect
CONNECTINGTURNTABLETOPHONO1 AND2
Connectthecablefromthe"left"channelofthe
turntableintotheL PHONO1 INPUTjack.Connect
the"right"channelintotheR PHONO1 INPUTjack.
Connecta secondturntableinthesamemanner
tothePHONO2 INPUTjacks.Shortingplugsare
shippedinthePHONO2 INPUTjackstoeliminate
noiseifa secondturntableisnotused.Remove
theseshortingplugswhenconnectingthesecond
turntable.Keepthemforpossiblefutureuse.DO
NOTplugtheshortingplugsintoanoutputjackas
thismaypreventoperationoftheMA6200.
GROUNDCONNECTION
Asinglegroundpostisprovided.Groundsforturn-
tables,recordchangers,tapedecks,etc.aretobe
connectedtothispost.Theleftandrightprogram
cablesandthegroundwirefromthatsourceshould
bewoundortwistedtogether.Toavoidhummake
surethegroundwiredoesnotmakeanyconnec-
tionstotheshieldsoftheleftandrightprogram
cablesbetweentheprogramsourceandtheMA
6200.
CONNECTINGA STEREOTUNERANDAUX1 AND2
Connectthecablefromthe"left"channeltuner
outputtotheL TUNERINPUTjack.
Connectthecablefromthe"right"channeltuner
outputtotheR TUNERINPUTjack
AUX—Anyhighlevelprogramsourcesuchasa
tuner,a TVsetora taperecordercanbeconnected
totheAUX1 and2 INPUTjacks.Theconnectingpro-
cedureisthesameasforthetunerinput.
CONNECTINGTAPERECORDERS
ToRecord:
Connecta cablefromtheL TAPE1 OUTPUTjack
tothelefthighlevelinputofthetaperecorder.Con-
necta cablefromtheR TAPE1 OUTPUTjacktothe
righthighlevelinputofthetaperecorder.
Connecta secondrecorderinthesamemannerto
theTAPE2 OUTPUTjacks.
ToPlayback/Monitor:
Connecta cablefromtheleftchanneloutputofa
taperecordertotheL TAPE1 INPUTjack.Connecta
cablefromtherightchanneloutputofa tape
recordertotheR TAPE1 INPUTjack.
Connecta secondrecorderinthesamemannerto
theTAPE2 INPUTjacks.
CONNECTINGACPOWER
TheMA6200ACpowercordistobepluggedinto
a120volt50/60Hzwalloutlet.
TherearetwotypesofACpoweroutletsonthe
backpaneloftheMA6200;threeblack,andtwo
green.
ThegreenACpoweroutletsareonatalltimes.
PlugtheACpowercablesfromtheturntableintothe
greenTURNTABLEpoweroutletsontherearpanel.
Thethreeblackoutletsareswitchedonandoff
whentheamplifieristurnedonoroff.Thesearein-
tendedforequalizersandotheraccessories.
ThePOWERONpushbuttonsharesACpower
control,withtheACpowerswitchona turntable,
througha currentdetectingswitchcircuit.Onthe
rearpaneltheTURNTABLEAUTO/MANUALswitch
selectsthemodeofoperation.
WhentheswitchisintheAUTOpositionanda
turntablepluggedintooneofthegreenACpower
outlets,theACpowertothereceiverandtothe
blackACpoweroutletscanbecontrolledbythe
4

5
TO
120V50/60
Hz
POWER
SOURCE
AC
POWER
TO
TURNTABLES
CONNECTIONS
FOR
TUNERS,TURNTABLES,
AND
TAPERECORDERS
TAPE
RECORDER 1
AC
POWER
TO
TUNERS,TAPE
RECORDERS,
AND
EQUALIZERS.
TAPE
RECORDER
2
TURNTABLE
#2
TURNTABLE
#1
FM
ANTENNA
TUNER

turntableon/offswitch.WhenACpowertotheturn-
tableisturnedon,automaticallytheinstrumentand
theSWITCHEDblackACpoweroutletsareturned
on.Thesystemwillremainonuntiltheturntableis
turnedoff.ThePOWERONpushbuttoncontrolsthe
ACpowerforanysourceotherthantheturntable.
IntheMANUALpositiononlythePOWERON
pushbuttonwillturnACpoweronoroff.
Someturntableshaveelectroniccircuitsthat
drawcurrentallthetime.Tousetheseturntablesthe
AUTO/MANUALswitchmustbeintheMANUAL
position.WiththeAUTO/MANUALswitchinthe
MANUALposition,ACpowertothesystemwillbe
controlledbythefrontpanelPOWERpushbuttononly.
FUSES
A5-ampfuseprotectstheMA6200circuits.The
fusedoesnotprotectadditionalequipmentcon-
nectedtotherearpanelACpoweroutlets.A one
ampfuseprotectstheturntableautooncircuit.If
thisfusefails,powertothegreenoutletswillbein-
terrupted.
CONNECTINGLOUDSPEAKERSFORSTEREO
Allspeakersareconnectedtothepushconnec-
torsontherearpanel.Whenstereospeakershave
beenconnectedtotheproperpushconnectors,the
correspondingfrontpanelpushbuttonsturnthe
speakersonoroff.
Selectionofthepropergaugewiretoconnectthe
loudspeakerspreservesthequalityofsoundrepro-
ductionforwhichtheloudspeakershavebeende-
signed.Ifundersizewireisused,resistanceisadded
totheamplifier/loudspeakercombinationwhich
adverselyaffectstheperformance.Addedresis-
tancecausesreductionofdampingcharacteristics,
modificationoffrequencyresponseandreductionin
poweroutput.
Uselampcord,bellwire,orwirewithsimilartype
ofinsulationtoconnectthespeakerstotheam-
plifier.Inallcases,theleadstoandfromthespeaker
shouldbetwinconductorortwistedtogether.When
using8 ohmspeakersandforthenormallyshort
distancesofunder30feetbetweentheamplifierand
speaker,No.18wireorlargercanbeused.For
distancesover30feetbetweentheamplifierand
speakeruselargerdiameterwire.Selectthecorrect
sizewireforthewirelengthfromthechart.Itis
recommendedthattheDCresistanceofthespeaker
leadsbelessthan5%ofthespeakerimpedance.Up
to10%canbetolerated.Resistanceoftheleads
shouldbecomputedforthelengthofwirebothto
andfromthespeakerorspeakers.
Formultiplespeakeroperation,runseparate
leadsfromtheamplifiertothespeakers.
CONNECTINGONELOUDSPEAKERFORMONO
TheleftandrightoutputsoftheMAC6200mustcon-
necttoseparateloudspeakers.Donotparallelthe
outputconnectionsfora singleloudspeaker.Ifthe
leftandrightoutputsareconnectedtogetherex-
cessiveheatisgeneratedinthepoweramplifiers
whichcausesdamageeventhoughtheMODE
SELECTORpushbuttonisintheMONOposition.If
youwishtodrivea singleloudspeaker,putthe
MODESELECTORinMONOandconnecttheloud-
speakertotheleftortherightspeakerpushconnec-
torsonly.Itisnotnecessarytoconnecta loadtothe
otherchanneloutput.
CONNECTINGA MclNTOSHEQUALIZER
OntheJUMPERpanel,removethejumpersbet-
weenthePREAMPOUTjacksandpowerAMPINput
jacks.Theenvironmentalequalizerisconnectedbet-
weenthesejacks.Usestandardshieldedcables.
ConnectthePREAMPOUTtotheinputofthe
equalizer.Connecttheoutputoftheequalizertothe
powerAMPINputjack.
MAXIMUMWIRELENGTHS
Wire
Gauge
22
20
18
16
14
12
10
For4 OhmLoad
Feet
6
10
15
25
40
60
100
Meters
1.8
3.1
4.6
7.6
12.2
18.3
30.5
For8 OhmLoad
Feet
12
20
30
50
80
120
200
Meters
3.7
6.1
9.1
15.2
24.4
36.6
66.0
Wirelengthsaboverepresentthewireresistanceequalto5%
ofthespeakerimpedance.
6
Connecttheleadsfromtheleftmainloudspeaker
totheSPEAKER1 LeftandCommonpushconnec-
tors.Connecttheleadfromtherightmain
loudspeakertotheSPEAKER1 RightandCommon
pushconnectors.Connecttheleadsfroma second
leftloudspeakertotheSPEAKER2 LeftandCom-
monpushconnectors.Connecttheleadfroma se-
condrightloudspeakertotheSPEAKER2 Rightand
Commonpushconnectors.Connecttheleadsfrom
athirdleftloudspeakertotheSPEAKER3 Leftand
Commonpushconnectors.Connecttheleadfroma
thirdrightloudspeakertotheSPEAKER3 Rightand
Commonpushconnectors.
ThepushconnectorontheMA6200willacceptup
to16gaugewire.Whenlargerwireisuseditwillbe
necessarytosplicea shortlengthof16gaugewire
totheendsoftheheavierwiretomakeconnections.
Asimilararrangementmayberequiredtoconnectat
thespeakers.

SPEAKERSYSTEM
#1
LEFTRIGHT
LEFT
SPEAKERSYSTEM
#2
RIGHT
LEFT
SPEAKERSYSTEM
#3
RIGHT
CUSTOM
ENVIRONMENTAL
EQUALIZER
CONNECTIONS
FOR
ENVIRONMENTAL
EQUALIZER
AND
LOUDSPEAKERS
7

TheFrontPanelControlsand
HowtouseThem
INPUTSELECTOR
TheINPUTSELECTORIsa fivepositionswitch
thatconnectsthechoseninputprogramtothepro-
percircuitsintheMA6200.
AUX1:Connectstothehighlevelinput,anyout-
putfroma highlevelprogramsourcerequiringflat
amplification.Sucha sourcecouldbea television
set,playbackfromanothertaperecorder,anaddi-
tionaltuner,etc.
responsehasbeenshapedaccordingtotheRIAA
standardtocompensateforthecharacteristicsofa
magneticphonocartridge.
PHONO2:SameasPHONO1 butfora second
phonosystem.
MODESELECTOR
TheMODESELECTORfacilitatestheaccuratead-
justmentofa stereosystemforsomedifferences
causedbyroomacoustics,loudspeakerplacement
andtheothercomponentsusedinthesystem.
TheMODESELECTORswitchconnectsthepro-
gramtotheloudspeakerinsevenways:
LtoL andR:Connectstheleftprogramtoboth
loudspeakers.
RtoL andR:Connectstherightprogramtoboth
loudspeakers.
AUX2:SameasAUX1 butfora secondhighlevel
programsource.
TUNER:ConnectstheoutputfromanyAM,FMor
MPXFMtunertothehighlevelinputstage.Inthe
TUNERpositiontheMA6200hasflatamplification.
PHONO1:Connectstheoutputofanymagnetic
phonocartridgetothelowlevelinputstage.The
8

STEREOREV:Connectstheleftprogramtothe
rightloudspeakerandtherightprogramtotheleft
loudspeaker.
STEREO:Connectstheleftprogramtotheleft
loudspeakerandtherightprogramtotheright
loudspeaker.
MONO(L+ R):Addstheleftandrightprograms
togetherandconnectstobothloudspeakers.
L+ R toL:Connectstheleftplusrightprogramto
theleftloudspeakeronly.
L+ R toR:Connectstheleftplusrightprogramto
therightloudspeakeronly.
VOLUMECONTROL
TheVOLUMEcontrol
isa precisionstepcon-
trolmanufacturedfor
MclntoshLaboratory.It
has32stepswitha 70
dBrange,plusvolume
off.Leftandrightchan-
neltrackingarewithin
1dB.Thisextremeaccuracyisobtainedthrough
specialelectronicallycontrolledresistanceelement
trimming.
BALANCEand
LOUDnessCONTROLS
TheBALANCEand
LOUDnesscontrolsare
concentric.TheBAL-
ANCEcontrol[large
outerknob]adjustsfor
equalvolumeofeither
theleftorrightchan-
nels.Thevolumeofthechannelscanbevaried
relativetoeachother.
left.. . turningthecontroltotheleftaccentstheleft
channelbyreducingtherightchanneloutput.
right. . . turningthecontroltotherightaccentsthe
rightchannelbyreducingtheleftchanneloutput.
TheLOUDnesscontrol[smallcenterknob]in-
creasesbothbassandtreblefrequenciesofboth
channelsasitisturnedclockwise.Adjustmentof
theLOUDnesscontrolallowslife-likefrequency
balancewhenplayingmusicsoftly.Itsfrequency
responsecontourisaccuratelymodeledafterthe
familyof"EqualLoudness"curvesidentifiedby
FletcherandMunson.
Theloudnesscircuitryiscompletelyindependent
ofthevolumecontrol.Therefore,anydesired
amountofcompensationcanbeintroduced
regardlessofvolumecontrolposition.
Frequencyresponseisflatandthereisno
loudnesscompensationwhentheknobisturnedful-
lycounter-clockwisetothe"flat"position.
EQUALIZERFREQUENCYCONTROLS
EachoffiveEQUALIZERFREQUENCYcontrols
modifiesupwardordownwardthetonebalanceofa
bandoffrequenciescenteredonthefrequency
markedabovethecontrol.Theflatpositionofthe
controlhasa detentforeasyreference.Eachcontrol
provides12dBboostorcutatthespecifiedcenter
frequency.
UsetheEQUALIZERFREQUENCYcontrolsto
modifythesoundandtonebalanceofprogram
material.Herearesomesuggestionsfromwhichto
start:
ProblemEqualizerCorrection
BasstooweakRaise30and/or150
MalevocalistneedsreinforcingRaise150
FemalevocalistreinforcingRaise500
HumonprogramReduce30
Violins,trumpetsdullRaise1500
Drum"brushes"notaudibleRaise10K
HEADPHONEJACKS
ThefrontpanelHEADPHONEjackshavebeen
designedtofeedlowimpedancedynamichead-
phones.Electrostaticheadphonesgenerallyrequire
higherpowerthandynamicheadphones.Theymust
beconnectedtothespeakerpushconnectorsonthe
rearpanel.
PlugheadphonesintoeitherfrontpanelHEAD-
PHONEjack.AdjustthefrontpanelVOLUMEcontrol
forcomfortableheadphonelistening.
Signaltotheheadphonejacksisnotaffectedby
theSPEAKERswitches.
TAPEPUSHBUTTONS
IMPORTANT:WhentheMA6200isoperatedwith
eitherMONITORpushbuttonattheinposition,the
programheardwillbethatfromthetaperecorders
only.Signalfromanyothersourcewillnotbeheard
fromtheloudspeakers.Tohearanyothersource,
makesuretheMONITORpushbuttonsareOUT.
TheMONITORswitchesaremechanicallyin-
terlockedtopreventsimultaneousmonitoringfrom
twotaperecorders.Ifonebuttonisattheinposi-
tion,itmustbepushedagaintoreleaseittotheout
positionbeforetheotherbuttoncanbepushed.
9

TheMA6200isdesignedsoitmaybeusedwith
twotaperecorders.Thefourleftpushbuttonscon-
trolthesignaloutputoftheserecorders.Theypermit
recordingstobemonitoredastheyarebeingrecord-
ed,orcopyingoftapesfromonerecordertoanother
whilelisteningtoa separateprogramortheplay-
backofeitherrecorder.
MONITORTAPE1 pushbuttonout:Theprogram
sourceasselectedbytheINPUTSELECTORisfed
tothepoweramplifiersandheardthroughthe
loudspeakers;pushbuttonin:Signalfroma tape
recorderpluggedintoINPUTSTAPE1 isfedtothe
poweramplifiersandheardthroughtheloud-
speakers.
MONITORTAPE2 Pushbutton:Functionssimilar-
lytomonitorTape1.Italsocontrolstheprogram
froma taperecorderpluggedintothefrontpanel
TAPEjacks.Whena taperecorderispluggedinto
thefrontjacksthetapeinputcircuitistransferred
fromtherearTAPE2 INjacktothefrontjack.The
taperecorderpluggedintotheTAPE2 INjackonthe
rearpanelisautomaticallydisconnected.
TAPECOPYT1T2pushbuttonin:connectsthe
outputfromtaperecorder1 totheinputoftape
recorder2 withoutaffectingtheprogrambeing
heardfromthespeakers.Inthispositiona copyof
theprogramontaperecorder1 canbemadeontape
recorder2.TomonitortheoriginaluseMONITOR
TAPE1 pushbuttonandtomonitorthecopyuse
MONITORTAPE2 pushbutton.
TAPECOPYT2T1pushbuttonin:connectsthe
outputfromtaperecorder2 totheinputoftape
recorder1 withoutaffectingtheprogrambeing
heardfromthespeakers.Inthispositiona copyof
theprogramonrecorder2 canbemadeonrecorder
1.TomonitortheoriginaluseMONITORTAPE2
pushbuttonandtomonitorthecopyuseMONITOR
TAPE1 pushbutton.
TAPERECORDERFRONTPANELCONNECTION
Inputandoutputfacilitiesareavailableatthe
TAPEIN-OUTjacksonthefrontpanel.Thesefront
paneljacksmakeconnectionswithouthavingtoget
attherearpanel.Whenusingthefrontpaneljacks,
therearTAPE2 INjackisautomaticallydiscon-
nected.A metalshielded1/4inchstereophoneplug
isusedforbestshielding.Connectionsfollowthein-
dustrystandardsandaretip:leftsignal,ring:right
signal,andsleeve:commonground.
SPEAKERS1,2 and3 PUSHBUTTONS
Wheneachofthesepushbuttonsispushedin,a
pairofloudspeakersisconnectedtothepower
amplifieroutputs.Speaker1,2 and3 maybe
selectedoneata time,anycombinationorallat
once.
POWERONPUSHBUTTON
ThePOWERONpushbuttonsharesACpower
control,througha currentdetectingswitchcircuit,
withtheACpowerswitchona turntable.Ontherear
paneltheTURNTABLEAUTO/MANUALswitch
selectsthemodeofoperation.
WhentheswitchisintheAUTOpositionanda
turntableispluggedintooneofthegreenACpower
outletstheACpowertotheMA6200andtotheblack
ACpoweroutletscanbecontrolledbytheturntable
on/offswitch.WhenACpowertotheturntableis
turnedon,automaticallytheMA6200andtheSWIT-
CHEDblackACpoweroutletsareturnedon.The
systemwillremainonuntiltheturntableisturned
off.ThePOWERONpushbuttonswitchparallelsthe
automaticturntablepowercontrolfeature.The
POWERONpushbuttonisusedtoturnonandoff
powerwhentheturntableisnotused.ThePOWER
ONpushbuttonmustbeoutorofffortheturntable
tocontroltheACpower.
IntheMANUALpositiononlythePOWERON
pushbuttonwillturntheMA6200andblackoutlet
ACpoweronandoff.
POWERGUARDINDICATORLAMPS
POWERGUARDassuresthatthepoweramplifier
sectionoftheMA6200cannotbeoverdriven,thus
amplifieroutputclippingiseliminated.Clippingis
causedwhentheamplifierisaskedtoproducemore
poweroutputthanitcandeliverwithlowdistortion.
Amplifiersarecapableofdeliveringlargequantities
10

ofpowerwhenthey
aredriventoclipping
andcanhavemore
than40%harmonic
distortion.Theextra
energycontentofthe
clippedsignalwill
damagemostspeak-
ers.A Mclntoshad-
vancementhelpsto
protectyourspeaker
fromthiskindofdamage.TheMA6200hasa builtin
"waveformcomparator"thatcomparesthewave
shapeoftheinputsignalwiththeoutputsignal.If
thenon-linearitybetweenthetwosignalsexceeds
0.5%thePOWERGUARDcircuitoperates.Opera-
tionisindicatedwhentheredlimitindicatorsturn
on.Aslongastheamplifieroperateswithout
overloadthenormalindicatorilluminates.
PUSHBUTTONINDICATORLAMPS
Theseareeightredindicatorlampsabovethe
pushbuttonswitches.Theyindicatethefunction
selectedbythecorrespondingpushbutton.Thesein-
dicatorsarealsoconnectedtoaninternalthermal
overloadprotectorcircuit.Intheeventofhighinter-
naltemperaturestheseindicatorswillextinguish
andoutputpowerwillbedisconnectedfromthe
loudspeaker.Whentheunitcoolsnormaloperation
willberestored.
11

PerformanceLimits
WepromiseyouthattheMA6200youbuymustbe
capableofperformanceatorexceedingtheselimits
atthetimeofpurchaseoryougetyourmoneyback.
MclntoshPERFORMANCELIMITSarethemaximum
departurefromperfectionpermittedfora Mclntosh
instrument.
PERFORMANCE
Mclntoshaudiopowerratingsareinaccordance
withtheFederalTradeCommissionRegulationof
November4,1974concerningpoweroutputclaims
foramplifiersusedinhomeentertainmentproducts.
POWEROUTPUT
100Wattsminimumsinewavecontinuous
averagepoweroutputperchannel,bothchannels
operatinginto4 ohms,20Hzto20kHz,withnomore
than.05%totalHarmonicDistortion.
75Wattsminimumsinewavecontinuousaverage
poweroutputperchannel,bothchannelsoperating
into8 ohms,20Hzto20kHz,withnomorethan.05%
totalHarmonicDistortion.
OUTPUTLOADIMPEDANCE
4ohms,8 ohms.
RATEDPOWERBAND
20Hzto20kHz
TOTALHARMONICDISTORTION
.05%maximumatanypowerlevelfrom250
milliwattstoratedpowerperchannel,20Hzto
20kHz,bothchannelsoperating.
INTERMODULATIONDISTORTION
.05%maximumatanypowerlevelfrom250
milliwattstoratedpowerperchannelwithboth
channelsoperatingforanycombinationoffrequen-
cies20Hzto20kHz.
FREQUENCYRESPONSE
20Hzto20kHz+0,-0.5dBatratedpower
HUMANDNOISE
PowerAmp:105dBA,100dBunweighted,
belowratedoutput
Tape& AuxInput:100dBA,95dBunweighted,
belowratedoutput
PhonoInput:85dBA,80dBunweighted,
below10mVinput
DAMPINGFACTOR
Greaterthan30
INPUTSENSITIVITYANDIMPEDANCE
PowerAmp:2.5Volts22,000ohms
Tape& Aux:250mV100,000ohms
Phono:2 mV47,000ohms,100pf
TAPEOUTPUT
Aux,Tape:250mVwithratedinput
Phono:250mVwithratedinput
PROGRAMEQUALIZER
±12dBat30,150,500,1,500,and10,000Hz
POWERREQUIREMENT
120Volts,50/60Hz,0.5to4 amps(50to400watts).
SEMICONDUCTORCOMPLEMENT
42Transistors
13IntegratedCircuits
25Diodes
1SiliconControlledRectifier
MECHANICALINFORMATION
SIZE:FrontPanelmeasures16incheswide(40.6
cm)by5 7/16incheshigh(13.8cm).Chassis
measures143/4incheswide(37.5cm)by4 13/16in-
cheshigh(12.2cm)by13inchesdeep(33.0cm),in-
cludingPANLOCshelfandbackpanelconnectors.
Knobclearancerequiredis1 1/4inches(3.2cm)in
frontofthemountingpanel.
FINISH:Frontpanelisanodizedgoldandblack
withspecialgold/tealnomenclatureillumination.
Chassisisblack.
MOUNTING:ExclusiveMclntoshdevelopedpro-
fessionalPANLOC
WEIGHT:30pounds(13.6kg)net.42pounds(19.1
kg)inshippingcarton
12

PerformanceCharts
POWEROUTPUTSECTION
HARMONICDISTORTIONVSPOWER
RL= 8 OHMS,BOTHCHANNELSOPERATING
POWEROUTPUTINWATTS
100
1k
POWEROUTPUTSECTION
BOTHCHANNELSOPERATING
.05%THDPOWERBANDWIDTH
10
100 1k
FREQUENCYHz
10k
100k
INTERMODULATIONDISTORTION
vs.
POWEROUTPUT
8OHMOUTPUT
INPUTFREQUENCIES60HzAND7 kHz
INPUTRATIO:4.1
OUTPUTSIGNALWAVEFORMSHOWINGACTION
OFPOWERGUARDTOELIMINATEOUTPUTSIGNAL
CLIPPING.AMPLIFIERINPUTISOVERDRIVENBY
20dBFORBOTHOSCILLOGRAMTRACES.
POWEROUTPUTINEQUIVALENTAVERAGEWATTS
TIME
13
0.1
.08
.06
.04
-02
0
0.1
1
10
HARMONICDISTORTION
IN
PERCENT
120
100
80
60
40
20
0
POWEROUTPUT
IN
WATTS
RMS
INTERMODULATIONDISTORTION
IN
PERCENT
.3
.2
.1
0
.11 10100
OUTPUT
SIGNAL
AMPLITUDE

LOUDNESSRESPONSE
201001k10k20k
FREQUENCYINHERTZ
FREQUENCYRESPONSEOF
EQUALIZERFREQUENCYCONTROLS
SETATMAXIMUMANDMINIMUM
20
15
10
5
0
-5
-10
-15
-20
201001k10k20k
FREQUENCYINHERTZ
PHONOEQUALIZATION(RIAA)RESPONSE
100
1k
FREQUENCYINHERTZ
10k20k
14
20
15
10
5
0
RESPONSE
INdB
20
10
0
-10
-20
RESPONSE
INdB
RESPONSE
INdB

TechnicalDescription
AUDIOSECTION
EachchanneloftheMA6200hasfourbasicsec-
tions.Theyare:phonopreamplifier,highleveland
loudnessamplifier,equalizeramplifier,andpower
amplifier.
PHONOPREAMPLIFIER
Thephonopreamplifierusesa hightechnologyin-
tegratedcircuitoperationalamplifier.Itsdifferential
inputstagehasbeenoptimizedforlownoiseand
lowdistortionperformance.Openloopgainofthis
integratedcircuitis100,000.Withhighopenloop
gaina largeamountofnegativefeedbackcanbeus-
edaroundthephonopreamplifiertofurtherreduce
noiseanddistortion.Thefeedbacknetworkalsopro-
videsprecisionRIAAfrequencycompensation.The
networkuses1%metalfilmresistorsand5%poly
filmcapacitors.Toachievelownoiseperformanceit
isessentialthatthefeedbacknetworkbeverylow
impedance.Asa consequence,thepreamplifier
mustbecapableofoperatingasa poweramplifierto
drivethisimpedance.Theactualpoweroutput
capabilityofthispreamplifierstageismorethan100
milliwatts,a greatmarginbeyondthatwhichisre-
quired.
Inputsensitivityofthephonopreamplifieris2
millivolts.Thegainoftheamplifieris42dBat1000
Hz.Thephonopreamplifierhasa verywidedynamic
range.At1000Hzthephonoinputcircuitwillaccept
100millivoltswithoutoverload,a voltagefargreater
thantheoutputofanycurrentmagneticphonocar-
tridge.Phonoinputoverloadthereforeisvirtuallyim-
possible.A signallevelof10millivoltsatthephono
inputat1000Hzwillproduce1.2voltsatthetape
output.Thetapeoutputhasa sourceimpedanceof
200ohms.Formostefficientsignaltransferthetape
outputshouldoperateintoa loadimpedanceof
5,000ohmsorgreater.
HIGHLEVELAMPLIFIER
Attheinputtothehighlevelorloudnessamplifier
thesignalpassesthroughthemodeswitch,then
throughthevolumecontrol,andintotheamplifier.In
thepastloudnesscontrolshavetypicallyusedsim-
plepassivecircuitsconnectedtoa taponthe
volumecontrol.Asa consequence,compensation
accuracywasdependentonmanyvariablessuchas
volumecontrolpositionanddifferencesininput
level.TheMA6200usesactivecircuitry.Thesame
typeofintegratedcircuitoperationalamplifierthat
isusedinthephonoamplifierisusedhere.Ithas
twofeedbackloops.Onefeedbackloopisflat.The
otherfeedbackloopconformstotheFletcher-
Munsonequalloudnesscompensation.A poten-
tiometerisplacedbetweenthesetwofeedback
loopsmakingitpossibletoselectanycombination
ofthetwofroma flatresponsetofullloudnesscom-
pensation.Theoverallgainofthestageis20dBand
isnotaffectedbythepositionoftheloudnesscon-
trolatmidfrequencies.
EQUALIZERAMPLIFIER
Theequalizeramplifierisconstructedwiththe
sameoperationalamplifiersasusedinprevious
amplifiers.Fiveotheroperationalamplifiersare
eacharrangedinanactivecircuitconfigurationthat
istheequivalentofa seriestunedcircuit,oneat
eachofthefivecenterfrequencies.Eachseriestun-
edcircuitisinserted,viatheequalizercontrolpoten-
tiometer,ineithertheinputcircuitorfeedbackcir-
cuitoftheequalizeramplifiertherebyprovidinga
boostandcutcapabilityof12dBforeachbandof
frequencies.
POWERAMPLIFIER
Theinputimpedanceofthepoweramplifieris
22,000ohmsandrequires2.5voltsrmstodrivethe
amplifiertoratedoutput.Theshortjumpersonthe
rearpaneloftheMA6200connecttheequalizer
amplifieroutput[PREAMPOUT]andpoweramplifier
input[AMPIN].Attheinputofthepoweramplifier
twotransistorsareconnectedasa differential
amplifier.Thetwoinputsignalstothedifferential
amplifieraretheinputsignalandthenegativefeed-
backsignalfromthepoweramplifier.Thedifferen-
tia!amplifierpermitsthebestuseofnegativefeed-
backtomaintainlownoiseandlowdistortionperfor-
mance.Theoutputsofthedifferentialamplifierare
combinedina currentmirrortoa singleoutput.The
currentmirrorfeedsa linearvoltageamplifierwhich
inturndrivestwomediumpowerdrivertransistors.
Thedrivetransistorsfeedtheoutputstages.The
outputsectionisarrangedasa fullycomplementary
directcoupledseriespush/pullamplifier.Thepower
transistorsusedintheoutputcircuitareselectedfor
theirhighpowerdissipationcapability,widefre-
quencyresponse,andlargesafeoperatingarea.The
powertransistorsaremountedonlargeblack
anodizedheatsinkstoassurethatundernormal
operatingconditionsthetransistorswilloperateata
lowtemperature.Ifoperatingtemperaturesshould
increaseduetoa shortedspeakerorrestrictedven-
tilation,anautomaticsensingdeviceturnsthe
speakercircuitoff.Thespeakercircuitwillturnon
againwhenthetemperaturehasreturnedtoitsnor-
mallimits.Thisadditionalprotectionassuresyouof
reliabilityevenunderthemostextremeoperating
15

conditions.Tofurtherinsurereliabilitya special
poweroutputSENTRYMONITORINGCIRCUIT
preventsfailureofthepoweramplifiertransistors
duetoexcessivemismatchorshortingoftheoutput.
WhentheMA6200operatesnormallytheSENTRY
MONITORINGCIRCUIThasnoeffectonsignals
passingthroughthepoweramplifier.Ifthepower
dissipationintheoutputtransistorsshouldrise
abovenormaldesignlimitstheSENTRYMONITOR-
INGCIRCUITrestrictsthedrivetotheoutputstage
whichreducesthedissipationintheoutputtran-
sistors.TheSENTRYMONITORINGCIRCUITactsin-
stantaneouslyforanyinputsignalorloadcombina-
tion.Thisarrangementassurescircuitreliability.On-
lyMclntoshgivesyouthisdegreeofprotection.
Thedirectcoupledcomplementaryamplifiercir-
cuitholdstheoutputatDCgroundpotentialwhen
thereisnosignalinputwhicheliminatestheneed
fora couplingcapacitorintheoutput.TheMA6200
poweramplifierisalldirectcoupledtoinsuremax-
imumlowfrequencyperformance.Inmostdirect
coupledcircuits,failureofanytransistorinthe
poweramplifierwillcausea DCpotentialtoappear
intheoutput.Toassurethatnodamagingorinterfer-
ingDCappearsacrosstheoutputterminals,a
special,veryfastactingprotectorcircuitconstantly
monitorstheoutputcircuitforDC.If,atanytime,a
constantDClevelappears,thespeakersarediscon-
nected.Theprotectivecircuitreactsinmilliseconds.
Speakersremaindisconnecteduntilthecausehas
beenfixed.Undernormaloperatingconditionsthe
protectivecircuithasnoaffectontheoperationof
theoutputcircuit.ThisisanotherexampleofMcln-
toshcontinuousprotection.
occurswhenanamplifierisaskedtoexceedits
designlimitsandthecapacityofthepowersupply.
SincePOWERGUARDdoesnotbegintoworkuntil
thispointisreached,thepowercapabilityofthe
amplifierisneveraffected.
TURNONDELAY
TheMA6200hastransient-freeturnonandturn
offcharacteristics.A heavydutyrelay,time-
controlledbya transistorswitch,connectstheout-
puttothespeakers.Thecontroltothetransistor
switchisderivedfroma longtimeconstant
capacitorchargingnetworkthatturnstherelayon
approximatelytwosecondsafterthepowerswitch
isturnedon.Thesamecircuithasa shortturnoff
timeconstantandtherelaydropsoutbeforethe
amplifier'smainpowersupplyhasa chanceto
discharge.
POWERSUPPLY
Twohighcurrentpowersupplies- a positive48
voltanda negative48voltDC- areusedtodrivethe
outputpoweramplifier.Verylargefiltercapacitors,
12,000microfaradseach,areusedtostorea large
amountofenergytoprovidegoodfilteringandex-
cellentvoltageregulation.Goodlowfrequency
responseandnegligiblelowfrequencydistortionin
thepoweramplifierstagesdependsontheregula-
tionofthepowersupply.Twoadditionalelec-
tronicallyregulatedpowersuppliesareusedinthe
MA6200.A + 18voltanda - 18voltlinesupplyall
operationalamplifiers.
POWERGUARD
Amplifiersarecapableofdeliveringlargequan-
titiesofpowerwhentheyaredriventoclipping.Clip-
pingiscausedwhentheamplifierisaskedtopro-
ducemorepoweroutputthanitcandeliverwithlow
distortion.A clippedamplifiercanhavemorethan
40%harmonicdistortion.Theextraenergycontent
oftheclippedsignalwilldamagemostloud-
speakers,particularlydelicatehighfrequency
tweeters.A newMclntoshadvancementhelpspro-
tectyourspeakersfromthiskindofdamage.TheMA
6200hasa built-inwaveformcomparatorwhichcom-
paresthewaveshapeoftheinputsignalwiththe
outputsignal.Ifthedisparitybetweenthetwo
signalsexceeds0.5%[equivalentto0.5%totalhar-
monicdistortion]a redlimitindicatorilluminates.
WithanyfurtherincreaseindistortionthePOWER
GUARDcircuitwilloperate.Thiscircuitlimitsthein-
putdynamicallysothattheamplifiercannotbeover-
driven.POWERGUARDeliminatesamplifieroutput
clipping.
POWERGUARDdoesnotlimitthedynamicrange
orthepoweroutputofthepoweramplifier.Clipping
16

Block
Diagram
MclNTOSH
MA
6200INTEGRATEDAMPLIFIER
17

MclNTOSHLABORATORYINC.
2CHAMBERSST.,BINGHAMTON,N.Y.13903-2699
607-723-3512
Thecontinuousimprovementofitsproductsisthepolicyof
MclntoshLaboratoryIncorporatedwhoreservetherightto
improvedesignwithoutnotice.
PrintedinU.S.A.
039179
BE032003