McIntosh C22 User manual

STEREO
PREAMPLIFIER
C22
CONTENTS
1
1
2
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3
8
8
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9
9
10
11
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11
16
16
GENERALDESCRIPTION
TECHNICALDESCRIPTION
MechanicalSpecifications
ElectricalSpecifications
FRONTPANELINFORMATION
INSTALLATION
CONNECTIONS
ACConnections
ACPower
InputConnections
OutputConnections
LoudspeakerPhasingConnections
GroundConnection
OPERATINGINSTRUCTIONS
GUARANTEE
3-YEARFACTORYSERVICECONTRACT
OWNER'SMANUAL
C22

C22STEREOPREAMPLIFIER
GENERALDESCRIPTION
TheMclntoshC22StereophonicPream-
plifierisa controlcenterforany stereophonic
soundsystem.Toincreaseyourenjoymentof
stereo,thiscontrolcenterdoesfourjobswith
precisecontrol.
First,thecontrolcenteramplifiesweak
electricalimpulses.Astherecordrotateson
theturntable,undulationsinthegrooves
movethepickupstylusapproximatelyone
thousandthofaninch,inany direction,from
therestposition.Fromthisslightmechanical
movement,thepickupstylusgeneratesa
weakelectricalimpulseontheorderofa few
thousandthsofa volt.Toamplifyandpre-
servetheinformationinsuchanelectrical
impulse,thefinestamplifierperformanceis
required.
Second,everysoundsystemisusedina
differentacousticalenvironment.Thetone
balanceofthemusicisaffectedbyvariations
inenvironment.Also,peoplelisteningtothe
musichavevaryingideasofcorrecttonebal-
ance.Tocompensatefortheseconditions,a
high-qualitytonecontrolcenterisneeded.
Third,allstereophonicandmonophonic
records,bothdomesticandforeign,are
recordedwithspecificfrequencyequaliza-
tion.Thecontrolcentermustaccuratelycom-
pensateforthisequalizationintroducedin
therecordingprocess.
Fourth,programscanoriginatefromsev-
eralsourcessuchastuners,records,tape
machines,microphones,etc.A controlcenter
isneededtoselectandswitchthesesources
separatelyorincombination.
Allofthesejobsareperformedwithexcel-
lencebytheC22.
TheC22alsousesthenew,exclusive
MclntoshPANLOCmethodofinstallation.
ThePANLOCsystemgivesyouabsoluteease
ofinstallation,operation,andmaintenance.
PANLOCisthefirstprofessionalinstallation
techniquetobeusedonstereoinstruments.
InthePANLOCsystema metalshelfis
mountedfirst,thenthepreamplifierslides
intopositiononthisshelf.Depressingthe
PANLOCbuttonsonthefrontpanellocksthe
preamplifierfirmlyintoplacefornormal
operation.Tounlockthepreamplifier,de-
pressthefrontpanelPANLOCbuttonsa
secondtime.Thepreamplifiercannowslide
forwardtotheADJUSTposition.Thepre-
amplifierwilllockinthispositionapproxi-
mately3 inchesfromthemountingpanel.
Nowyoucanadjusttheoutputlevelcontrols,
lowfrequencytrimcontrols,tapeequaliza-
tioncontrols,phaseswitchandpilotlamp
intensityswitch.Thesecontrolsaremounted
justbehindtheC22frontpanel.Depressing
theADJUSTpositionholdinglatchesonthe
sidesofthechassisallowsthepreamplifier
tobetakenoutofthePANLOCshelf,orto
slidebackintopositionagainstthemounting
panel.
Onceyouhaveenjoyedtheoutstanding
performanceoftheC22,youwillunderstand
whyMclntoshproductshaveearnedtheir
reputationas"THEBEST."YourMclntosh
C22Stereophoniccontrolpreamplifierwill
giveyouyearsofthefinestpossibleperform-
ance,andwillbecomea highlyvaluedpartof
yourhomemusicsystem.
TECHNICALDESCRIPTION
TheC22StereophonicPreamplifiercom-
binesexcellenceinperformancewitheaseof
operation.Themostoftenusedcontrolshave
largediameterknobs.A newtypeofrocker
switchisusedforthecontrolswithsimple
on-offfunctions.TheC22hasanilluminated
frontpanelwitha lightintensityswitchto
provideconvenientreadingunderlow-level
lightingconditions.TheModeandInput
Selectorswitchpositionsarealsoilluminated.
TheC22circuitconsistsof3 amplifier
sectionsinduplicatefortheleftandright
stereochannelstogetherwitha common
powersupply.Thefirstamplifiersectionis
1

theinputpreamplifierusedtoamplifyand
equalizesignalsfromphonographpickups,
microphonesortapeheads.Skillfulcircuit
layout,propergrounding,andadequate
shieldingreducethehumsolowitisvirtually
unmeasurable.Extremecareinmanufactur-
ingcombinedwithlownoisetubes,high
specificresistivitycircuitboards,metalfilm
andwirewoundresistorsachievesnewlowin
residualnoise.
Thesecondamplifiersectionfollowsthe
mainvolumecontrol,makingitimpossibleto
overloadthehighlevelinputcircuitsorany
followingcircuits.Thesamedesigntech-
niquesasusedinthepreamplifiersection
assurelownoiseandhum.TheBASSand
TREBLEfeedback-typetonecontrolsoperate
inconnectionwiththisamplifiersection.The
controlsareswitch-typewithapproximately
4dbchangeperstep.Exceedinglylowdistor-
tionandprecisecontroloffrequencyre-
sponsecontoursareassuredusingthis
arrangement.
Frontpaneltapejacksareprovidedfor
convenientuseofanexternaltapemachine.
TheTAPEJACKswitchconnectsthejacksfor
eitherplaybackorrecordingthroughtheC22.
Thethirdsectionisthecathodefollower
output.Thesharpcutoff(18dbperoctave)
RUMBLEandHF(highfrequency)filtersare
associatedwiththissection.OUTPUTLEVEL
controlsarelocatedattheinputsofthecath-
odefollowerstoallowsimplebalanceofthe
entireamplifier-speakersystem.TheOUT-
PUTLEVELcontrolsarelocatedontopofthe
C22,behindthefrontpanel.Thesecontrols
areconvenientlyaccessiblebyreleasingthe
PANLOCbuttonsandslidingtheC22outto
theadjustposition.
Thepowersupplydeservesspecialmen-
tion.Thepowertransformerisconstructed
with"core"typegrainorientedlaminations
andmagneticshieldingforlowexternalhum-
fields.Longliferectifierswithfullwave
rectification,filtercondensersectionalizing
andcarefulgroundingaddtothehum-free
longlifecharacteristicsoftheC22.
Specialattentionhasbeengiventothe
mechanicaldesign.ThePANLOCsystemis
thefirstprofessionalinstallationtechnique
tobeusedonstereoinstruments.The
PANLOCsystemgivesyouabsoluteeaseof
installation,operationandmaintenance.The
C22maybeconvenientlyinstalledinfurni-
turecabinets,custom-builtinstallations,pro-
fessionalrelayracksoranattractivefinished
Mclntoshcabinet.
MECHANICALSPECIFICATIONS
Size:
Frontpanel;16incheswideby57/16inches
high;chassis(includingPANLOCshelf)15
incheswideby5 incheshighby13inches
deep,includingconnectors;clearancein
frontofmountingpanelincludingknobs,
1½inches.
Weight:
16poundsnet,25poundsinshippingcarton.
Finish:
Anodizedgoldandblack(frontpanel).
ELECTRICALSPECIFICATIONS
PowerRequirement:
117volts50/60cpsAC,34watts.
InputSensitivityandImpedance:
Auxiliary,Tape,Tuner1,andTuner2:0.25
volts,250,000ohms.
Phono1 andPhono2:2 millivolts,47,000
ohms.
Microphone:2.5millivolts,1 megohm.
TapeHead:2 millivolts,1 megohm.
TapeCompare:0.25volts,250,000ohms.
FrequencyResponse:
±0.5dbfrom20cpsto20,000cps.
Distortion:
Lessthan0.2%at10voltsoutput.
Lessthan.02%at3 voltsoutput.
TotalNoise:
HighLevelInputs:85dbbelowratedoutput.
LowLevelInputs:Lessthan1.5microvoltsat
inputterminals.
2

MainOutput:
2.5voltswithratedinput.
TapeOutput:
.25voltswithratedinput.
LeftPlusRightOutput:
1voltfromgeneratorimpedanceof25,000
ohms.
VoltageAmplification:
Auxiliary,Tape,Tuner1,andTuner2:
ToMainOutput,20db(10to1).
ToTapeOutput,0 db(1to1).
Phono1 andPhono2 (At1 KC):
ToMainOutput,62db(1250to1).
ToTapeOutput,42db(125to1).
Microphone:
ToMainOutput,60db(1000to1).
ToTapeOutput,40db(100to1).
TapeHead(At500cps):
ToMainOutput,62db(1250to1).
ToTapeOutput,42db(125to1).
A.C.Outlets:
1unswitched(Red)forturntableortape
machine.
4switched.
Tubes:
6each12AX7.
TapeJackSwitch:
2position,connectspaneljackstoallow
signalstobefedfromortotheC22to
recordorplaybackusinganexternal
portabletaperecorder.
BassControls:
Separatechannel11positionswitchtype,
±20dbat20cycles.
TrebleControls:
Separatechannel11positionswitchtype,
±20dbat20,000cycles.
CompensatorSwitch:
RIAAorLPrecordequalization.
TapeSwitch:
Normal,orTapeMonitor.
RumbleFilter:
50cpscutoff.
HFFilter:
5000cyclecutoff.
AdditionalSet-UpControls:
Thefollowingcontrolsarelocatedbehindthe
frontpanelonthetopoftheC22chassis.
Thesecontrolsarereadilyaccessibleby
depressingthePANLOCbuttonstoslide
theC22forwardfromthemountingpanel:
OutputLevelControls(L,L + R,andR):
Allowsthebalanceoftheentiresystemto
beconvenientlyadjusted.
LowFrequencyTrimControls(LandR):
Allowsfrequenciesbelow100cpstobe
boostedupto6 dbtocompensatefor
unequalspeakerresponse.
TapeEqualizationControls(LandR):
Adjuststapeheadinputhighfrequency
response.
PhaseSwitch:
2position,normal(0°)orreverse(180°).
PilotLampIntensitySwitch:
2position,brightordim.
FRONTPANELFACILITIES
Figure1.C22FrontPanel.
3

INPUTSELECTOR
Figure2. INPUTSELECTORswitch.
Selectanyoneofeightprogramsources
withthisswitch:
1.AUX:anyauxiliaryservicerequiringflat
amplification,suchasa televisionset,is
connectedtotheC22throughtheAUX
position.
2.TAPE:anyself-containedtapemachine
(tapemachinehavingitsownplayback
preamplifier)isconnectedtotheC22
throughtheTAPEposition.
3.TUNER1:AMandFMorMPXFMoutputs
froma stereotunerareconnectedtothe
C22throughtheTUNER1 position.
4.TUNER2:sameasTUNER1.
5.PHONO1:connectstheC22forstereo
andmonophonicoperationforrecords.
6.PHONO2:sameasPHONO1.
7.MIC:stereomicrophonesareconnected
totheC22throughtheMICposition.
8.TAPEHD:a tapedeckthatdoesnotcon-
tainitsownplaybackpreamplifieriscon-
nectedtotheC22throughtheTAPEHD
position.
MODESELECTOR
UsetheMODESELECTORto:
Listentonormalstereo(4following
andpage13.
Reversetheleftandrightarrangement
ofmusicalinstruments(3following
andpage12).
Balancetheamplifiersandloudspeak-
ersina stereosystem(6and7 follow-
ingandpage11).
Listentomonophonicsound(1and2
followingandpage13).
Listenthrubothloudspeakerstoeither
trackofa stereoprogramsource(1and
2followingandpage13).
TurntheMODESELECTORto:
1.L TOL & R: connects the "left" input to
bothloudspeakers.
2.RTOL&R:connectsthe"right"inputto
bothloudspeakers.
3. STEREO REV:connects the "left" input to
the "right" loudspeaker andthe "right"
inputtothe"left"loudspeaker.
4. STEREO: connects the "left" input tothe
"left"loudspeakerandthe"right"input
tothe"right"loudspeaker.
5.MONO(L+ R):addsthe"left"inputand
the "right" input and then connects the
L+ R programtobothamplifiersand
loudspeakers.
6.L + R TOL:connectsthe"leftplusright"
programstothe"left"loudspeakeronly.
7.L -I-R TOR:connectsthe"leftplusright"
programs tothe "right" loudspeakeronly.
VOLUME
Figure3.MODESELECTORswitch.
Figure4.VOLUMEcontrol.
UsetheVOLUMEcontroltoregulatethe
combinedvolumelevelofbothchannels.
TurningtheVOLUMEcontrolclockwisein-
creasesvolumelevel.
4

BALANCECONTROLTREBLECONTROLS
Figure5. BALANCECONTROL.
UsetheC22BALANCEcontroltobalance
unequalvolumeintheleftandrightchannels
ofa programsource.Thevolumeofeach
speakersystemrelativetotheothercanbe
varied,atthesametimetheircombined
volumelevelismaintained.
LEFT. . . turningthecontroltotheleft
accentstheleftchannelbyreducingtheright
channeloutput.
RIGHT. . . turningthecontroltotheright
accentstheright channelbyreducingthe
leftchanneloutput.
BASSCONTROLS
Figure6.BASSCONTROLS.
UsetheLEFTandRIGHTBASSCON-
TROLStoregulatebassloudnesstotheleft
andrightspeakers,respectively.Clockwise
rotationincreasesbassloudness;counter-
clockwiserotationdecreasesbassloudness.
EachswitchstepoftheBASScontrolchanges
bassloudnessapproximately4 db.
Figure7.TREBLECONTROLS.
UsetheLEFTandRIGHTTREBLECON-
TROLStoregulatetrebleloudnesstotheleft
andrightspeakers,respectively.Clockwise
rotationincreasestrebleloudness;counter-
clockwiserotationdecreasestrebleloudness.
EachswitchstepoftheTREBLEControl
changestrebleloudnessapproximately4 db.
COMP(COMPENSATION)
Figure8.COMP(COMPENSATION)switch,
UsetheCOMPswitchtocorrectforphono
equalizationintroducedbytherecording
process.AllcurrentLPandStereorecordings
useRIAAequalization.Somestereoand
earlymonorecordingsuseLPequalization.
TAPEJACKS
UsetheC22TAPEJACKStoheara pro-
gramoriginatingfroma portabletapema-
chineortorecorda programpickedupbythe
C22ona portabletapemachine.
RECORD.... connectssignalsfromthe
reartapejackstotheINPUTSELECTOR
TAPEposition.Anyprogrampickedupby
theC22isconnectedtotheportablemachine
5

forrecording.
PLAYBACK. . . TAPEinputisswitched
fromreartapejackstofrontpanel telephone
jacks(lefttapeandrighttape).Anyprogram
originatingfroma portablemachinecon-
nectedtotheC22canbeheardbyrotating
theINPUTSELECTORtotheTAPEposition.
LEFTTAPE. . . telephonejackfemale
receptaclefortheleftchannelofa portable
tapemachine.
RIGHTTAPE. . . telephonejackfemale
receptaclefortherightchannelofa portable
tapemachine.
TAPE
RUMBLE
Figure9.TAPEswitch.
UsetheC22TAPEswitchtoknowinstan-
taneously,asyouarerecording,thatthe
musiconthetapeisacceptable.TheC22
TAPEswitchmakesitpossibletoinstanta-
neouslycomparerecordedmaterialwiththe
sourcesignal.Tapejacksonthebackpanel
accepta signalfroma taperecorderwitha
monitorheadandpreamplifier.
NORMAL. . . theprogramsourceisfed
throughthepoweramplifiersandtheloud-
speakers.
MONITOR. . . thesignalsourcebecomes
themonitoredprogramfromtherecorded
tapeandisfedthroughthepoweramplifiers
andloudspeakers.
POWER
TheC22andfourblackreceptacleson
thebackpanelareturnedonandoffbythe
POWERswitch.
Figure10.RUMBLEfilterswitch.
UsetheC22RUMBLEfiltertoreducelow-
frequencynoisecreatedbya turntableor
recordchangerandacousticallycoupled
feedback.
FLAT. . . filterdisconnected.
FILTER. . . low-frequencyrumblenoise
below50cpscreatedbya turntableor
recordchangerandacousticallycoupled
feedbackarereducedwhentheRUMBLE
filterbuttonispushedtotheFILTERposition.
H.F.(HIGH-FREQUENCYFILTER)
Figure11.H.F.(High-FrequencyFilter)switch.
Thisswitchminimizessurfacenoisewhen
reproducingold,badlywornrecordings.
FLAT. . . filterdisconnected.
FILTER. . . rollsoffresponsesharplyat
5KC.
.6

LOUDNESS
Figure12.LOUDNESSswitch.
UsetheLOUDNESSswitchintheCOM-
PENSATEDpositiontolistenatlowvolume
andstillhearfull-frequencyrange.Whenyou
turndownthevolume,themusicwillseemto
losemuchofitsbassandsomeofitstreble.
Thiseffectisduetothesensitivitycharacter-
isticsofhumanhearing.Theresponseofthe
humaneartobassandtreblepitchde-
creasesmorerapidlythanitsresponseto
notescenteredinthemidtonalrange.The
LOUDNESSswitchautomaticallyprovides
thecorrectamountofbassandtrebleboost
requiredtocompensateforthischangein
responseofthehumanearatlow-loudness
levels.WhentheLOUDNESSswitchismoved
totheCOMPENSATEDposition,itconverts
thevolumecontroltoa loudnesscom-
pensatedcontrol.
CONTROLSBEHINDTHEFRONTPANEL
DepressingthePANLOCbuttonsallows
theC22toslideforwardtoa pointapproxi-
mately3 inchesfromthemountingpanel.In
thisposition,additionalcontrolsontopofthe
C22chassisareavailable;thePHASEswitch,
LOWFREQUENCYTRIMCONTROLS,OUT-
PUTLEVELCONTROLS,TAPEEQUALIZA-
TIONCONTROLS,andthePILOTLAMP
INTENSITYswitch.
PILOTLAMPINTENSITY
UsethePILOTLAMPINTENSITYtoswitch
thefrontpanelpilotlampstoDIMorBRIGHT.
TAPEEQUALIZATION
UsetheTAPEEQUALIZATIONcontrolsto
compensatefor3%tapespeedforindividual
tapeheadcharacteristics.Thesecontrols
shouldbesettoNABfornormal7.5inch
tapespeedmachines.TurningtheTAPE
EQUALIZATIONcontrolsclockwiseincreases
thetrebleresponse;turningthemcounter-
clockwisedecreasestrebleresponse.
OUTPUTLEVELCONTROLS
UsetheOUTPUTLEVELcontrolstobal-
ancetheoverallamplifier-speakersystem.
Theminimumsettingoneachcontrolre-
ducestheoutputlevelapproximately15db.
TheL + R (leftplusright)controladjustsonly
theoutputfromtheL + R outputjack.This
controlcanturntheL + R signalcom-
pletelyoff.
LOWFREQUENCYTRIMCONTROLS
Usethesecontrolstoadjustforunequal
speakerresponseatlowfrequenciesdueto
roomlocationofspeakers.Approximately
6dbofboostbelow100cyclesisavailable.
Figure13.ControlsBehindtheFrontPanel.
7

PANLOCBUTTONS
At thebottomfrontcornersarethe
PANLOCbuttons.Aftera preamplifieris
installedonthePANLOCshelf,depressing
thePANLOCbuttonswilllockthepreampli-
fierfirmlyinposition.DepressingthePANLOC
buttonsa secondtime(aswitha ball-point
pen)willreleasethepreamplifier.Thepre-
amplifiercanthenbeslidforwardtothe
inspectionandadjustmentposition.Releas-
ingtheADJUSTpositionlatchesallowsyouto
slidethepreamplifiercompletelyoutofits
mountingshelf,orbackintonormaloperat-
ingposition.ThePANLOCsystemgivesyou
absoluteeaseofinstallation,operationand
maintenance.
INSTALLATION
TheC22canbeinstalledinconventional
furniturecabinets,custombuiltinstallations
orprofessionalrelayracks.Iftheunitistobe
placedona shelfortable-top,itisrecom-
mendedthatitbehousedina Mclntosh
cabinet.TheC22installsconvenientlyfrom
thefrontofthecabinetbyslidingintoits
PANLOCshelf.
TosupporttheweightoftheC22,the
woodpanelusedtomountitshouldbeat
least¼ inchthick.
TheC22installationshouldallowapproxi-
mately14inchesbehindthefrontpanelto
mountthePANLOCshelfandallowforcon-
nectingwires.Toallowsufficientspacefor
thecirculatingair,thedesirableminimum
internalcabinetdimensionsshouldbe16
inchesand5½inchesrespectively.
CONNECTING
ACCONNECTIONS
TherearefiveACoutletsontherearpanel
oftheC22(SeeFigurel4.)Thesereceptacles
havea maximumratingof660wattstotal.
Thepowertothefourblackreceptaclesis
controlledbythePOWERswitchonthefront
panel.Theredreceptacleisnotswitched.
Theredreceptacleisusedforpoweringa
turntableorrecordchanger.Thereceptacle
isnotswitchedsothattheturntablepower
willnotbeturnedoffwhiletheturntableidler
wheelisengaged.Theturntableisprotected
bythisarrangementbecauseitisnecessary
toturnofftheturntablewithitsowncontrol
switchsothatnodamagewillresulttothe
turntabledrivesystem.
Figure14.A-CConnections.
8

ACPOWER
PlugtheACpowercordin105voltto125
volt,50to60cyclepowerline.Thepower
usedbytheC22is34watts.
INPUTCONNECTIONS
TheC22provideseightseparateprogram
inputscontrolledbytheINPUTSELECTOR
switch.Oneinputfortapemonitorortape
comparisoniscontrolledbytheTAPEswitch.
Theinputprogramconnectionsshouldbe
madeinaccordancewithTable1.
Figure15.INPUTCONNECTIONS.
CONNECTION
TAPEMONITOR
(COMPARE)
AUX
TAPE
TUNER1 &
TUNER2
FUNCTION
Thetapemonitorinputacceptsa signalfroma tape
recorderwitha monitorheadandpreamplifier
Theauxiliaryinputacceptsanyauxiliaryservicerequir-
ingflatfrequencyresponse,suchasa T.V.set,tuner,
taperecorderwithitsownplaybackpreamplifier,etc.
Thetapeinputoperateswithtapemachinescontaining
theirownplaybackpreamplifier
ThetunerinputsacceptAMandFMoutputsfroma
stereotunerora pairofstereotunersorthemultiplex
outputofanadapterofmultiplextuner
INPUT
SENSITIVITY
0.25V
0.25V
0.25V
0.25V
INPUT
IMPEDANCE
250K
250K
250K
250K
Ifa phonocartridgerequireslessthan
47,000ohmsloadimpedance,a resistorcan
beaddedacrosstheterminalsofthecar-
tridgetoachievethecorrecttermination.
Thefollowingchartmaybeusedasa guide:
DesiredImpedance
47,000ohms(47K)
37,000ohms(37K)
27,000ohms(27K)
15,000ohms(15K)
6,800ohms(6.8K)
ResistorAcrossInput
NoResistor
180,000ohms(180K)
62,000ohms(62K)
22,000ohms(22K)
8,200ohms(8.2K)
CONNECTION
PHONO1 & 2
MAGNETIC
TAPEHEAD1 & 2
2-10 MV
MIC
FUNCTION
Thesejacksaretobeusedwithmagneticcartridges.. .
Thesejacksaretobeusedwitha tapedeckthatdoes
notcontainitsownplaybackpreamplifier
Thesejacksaretobeusedwithhighimpedancecrystal
ordynamicmicrophones
INPUT
SENSITIVITY
2MV
2 MV
2.5MV
INPUT
IMPEDANCE
47K
1megohm
1megohm
9

Figure16.Turntablesfeedinglow-levelinputs.
OUTPUTCONNECTIONS
There aretwo sets of outputs onthe left
halfofthebackpanel.(SeeFigure15)One
pairismarkedMAIN.Thesecondpairis
markedTAPE.
TheMAINoutputsconnecttopower
amplifiers(figure17).TheTAPEoutputfeeds
ataperecorder.
The MAIN jacks arefed from cathode
followers.Longercablesthanarenormally
suppliedcanbeconnectedbetweentheC22
andtheamplifiers.Thelengthofthecableis
limitedbythecapacityofthecable.Thetotal
capacitymustnotexceed1000mmf.For
instance:cableswitha capacityof25mmf
perfootmaybe40feetlong;13.5mmfper
footcablemaybe75feetlong.Theinput
impedanceoftheamplifiersshouldbe
50,000ohmsorgreater.
TheTAPEoutputisfedfroma cathode
follower.Theprogrammaterialfedoutofthe
TAPEoutputisnotaffectedbythesefront
panelcontrols:VOLUMEcontrol,BASScon-
trols,LFandHFfilterswitches,BALANCE
control,LOUDswitch,TAPEswitch,PHASE
switch,TREBLEcontrols,andMODESELEC-
TORswitch.
TheprogrammaterialfedoutoftheTAPE
outputisaffectedbythesefrontpanelcon-
Figure17.MAINOUTPUTConnectedto
PowerAmplifiers.
10

trols:INPUTSELECTORpositions,AUX,
TAPE,TUNER1,TUNER2,orMIC,the
MUTINGswitchandTUNINGcontrol.When
theINPUTSELECTORisturnedtoTAPEHD
thentheCOMPshouldbesettoRIAA.
Theinputimpedanceofthetaperecorder
shouldbe50,000ohmsorgreater.
AjackmarkedL + R OUTPUTislocated
nexttoMAINOUTPUTS.
Amonophonicsignalcanbedistributedto
otherroomsbyconnectinganotherpower
amplifiertothejackmarkedL + R.Thecable
connectingthisoutputtotheamplifiershould
nothavea capacityofmorethan1000mmf.
Theinputimpedanceofthepoweramplifier
connectingtothisoutputshouldnotbeless
than150.000ohms(150K).
LOUDSPEAKERPHASINGCONNECTIONS
Twopairsofscrewterminalsarelocated
onthelowerleftsectionoftheC22back
panel.Thespeakerleadsfromthe"left"
poweramplifiershouldbeconnectedtothe
screwterminalsmarkedFROMAMPLIFIER.
ThepairofterminalsmarkedTOSPEAKER
shouldbeconnectedtothe"left"loud-
speaker.
Theseconnectionsallowthefrontpanel
PHASEswitchtoreversethephaseonthe
leftloudspeaker.Thisarrangementiscon-
venientwhensettingupa stereosystem.
GROUNDCONNECTION
Asinglegroundpostisprovided.The
chassisgroundfromturntable,recordchang-
ers(motorsusedwitheach),tapedecks,
etc.,shouldbereturnedtothispost.Donot
duplicatethisgroundcircuit.Humislikelyto
beheardinthesystemifduplicateground
returnsareused.
Theleftandrightprogramcablesfrom
eachsourceshouldbetwistedtogetherand
thegroundwirefromeachsourcecanbe
woundortwistedinwiththesecables.To
avoidhum,makesurethegroundwiredoes
notmakeanyconnectionstoshieldsofthe
leftandrightchannelcablesexceptforthe
connectionprovidedwiththeC22groundpost.
OPERATINGINSTRUCTIONS
BALANCINGA STEREOSYSTEM
Theperformanceandenjoymentofa
stereosystemisgreatlyincreasedwhenthe
systemisproperlybalanced.Therearetwo
factorsthatrequirebalancing.Oneisthe
unequalprogramloudnessontheleftand
rightchannelsofa programsource.Thecon-
trolmarkedBALANCEontheC22isusedto
balanceunequalprogramloudness.Balanc-
inga programforunequalloudnessisex-
plainedunderADJUSTINGBALANCECON-
TROLTOCORRECTPROGRAMMATERIAL.
Theotherfactorthatrequiresbalancingis
systembalance.Thebalanceofthestereo
systemisaffectedbymanythingsincluding
roomacoustics,furnitureplacement,room
shape,smalldifferencesinloudspeakers,
etc.Balancingthesystemisdonebyadjust-
ingthecontrolsonthepoweramplifiers.
Tobeginbalancingthesystem,checkto
seethatthecontrolsontheamplifierare
properlyset.Iftheamplifierisa Mclntosh
MC225,settheinputswitchtoSTEREO.Turn
bothinputlevelcontrolstotheblackdotat
the12o'clockpositionofthecontrol.
Iftheamplifierisa MclntoshMC240or
MC275checktoseethatthecablesfromthe
C22arepluggedintotheSTEREOINPUT
jacks.ThensettheleverswitchtoSTEREO.
TurntheBALANCEcontroltothe0 markat
the12o'clockpositionofthecontrol.The
amplifiersarenowreadyfortherestofthe
stepstobalancingthesystem.
1.Playa familiarrecordingontherecord
player.
2.PushthetwoPANLOCbuttonstorelease
theC22fromthemountingshelf.Pullthe
C22towardyouuntilthelatchlocksen-
gageapproximately3 inchesfromthe
frontpanel.
3.TurntheINPUTSELECTORtothe
PHONOpositionintowhichtherecord
playerisconnected.
4.TurntheBASSCONTROLSandTREBLE
CONTROLSsothattheknobindicators
arecenteredbetweenthepanelmark-
ingsL andR.
5.TurntheBALANCEcontroltothecenter
or12o'clockposition.
6.PlacetheLOUDNESSswitchinthe
11

COMPENSATEDposition.
7.PlacetheTAPEswitchintheMONITOR
position.
8.PlacethePHASEswitchinthe0°position.
9.PlacetheRUMBLEfilterswitchinthe
FLATposition.
10.PlacetheH.F.cutofffilterswitchinthe
FLATposition.
11.TurntheMODESELECTORtotheL + R
TOL position.
12.Whiletheprogramisplaying,alternate
theMODESELECTORbetweentheL + R
TOR andtheL + R TOL position.On
amplifierssuchastheMC225,adjustthe
correctgaincontroluntiltheloudspeak-
ersareofequalloudness.OntheMC240
ortheMC275,turnthebalancecontrol
untiltheloudspeakersareofequal
loudness.
The stereo system isnow balanced. It will
remainbalancedthroughallmodesofopera-
tion.LeavetheC22extendedonitsPANLOC
stopsforthenextseriesofadjustments.
ADJUSTINGPHASE
1.SettheMODESELECTORtoSTEREO.
2.TurntheBASScontrolsandTREBLE
controlstostraightuppositionsothatthe
dialindicatorcentersbetweenthepanel
markingsL andR.
Standapproximately10feetinfrontof
andmidwaybetweentheloudspeakers.The
sourceofsoundshouldappeartobedirectly
infrontofyou.AlternatethePHASEswitch
between0°and180°.Ifthesoundisnot
directlyinfrontofyouinthe0°position,
reversetheleadstooneloudspeaker.The
PHASEcontrolisusedtocorrectphasein
thesourcematerialwhenevernecessary.
ADJUSTINGBALANCECONTROLAFTER
THESYSTEMHASBEENBALANCED
Whentheseinstructionshavebeencom-
pleted,theoverallsystemisbalancedandin
phase;readytodelivermaximumpleasure
andenjoyment.
Youmayheardifferencesinbalancefrom
onerecordtoanotherorfromonetapeto
another.Somerecordsortapesmaybe
recordedwithslightdifferencesbetween
channels.Thedifferencescanbecorrected
withtheBALANCEcontrolonthefrontpanel.
Ifthedifferenceisheardoneveryrecord,
thenthecartridgemayhavea verysmall
differenceinoutput.
ADJUSTINGFORSPECIALEFFECTS
HFCUTOFFFILTER
Ifyouwishtoreproduceold,badlyworn
records,youcanminimizethesurfacenoise
byswitchingtheHFcutofffiltertotheIN
position.
RUMBLEFILTER
Ifyouareusinga turntableorchanger
whichhaslow-frequencyrumblenoise,you
mayreduceitbypushingtheRUMBLEfilter
switchtotheFILTERposition.
BASSCONTROLSANDTREBLECONTROLS
Thetonebalancewhichyouhearwhen
listeningtoanorchestraisaffectedbythe
conductor'sinstructionstohismusicians,
theacousticalenvironmentinwhichyouare
listening,andyourownsubjectivehearing
interpretation.Consideringtheseconditions,
itiseasytoseewhytonebalancecontrols
playa majorroleincorrectingforthefollow-
ingfactors:
1.Eachperson'ssubjectiveideaoftone
balance.
2.Loudspeakerfrequencyresponsecharac-
teristics.
3.Loudspeakerplacementinthelistening
room.
4.Theconductor'sideaoftonebalanceat
thetimetherecordingwasmade.
5.Themicrophonefrequencyresponsechar-
acteristics.
6.Therecordingprocessinfluences.
Thesefactorscanbeconsideredas
environmentalinfluences.TheBASSCON-
TROLSandTREBLECONTROLSprovidea
degreeofcompensationforeffectsofen-
vironment.Listentoyoursystemwitheach
controlsetwiththeindicatorscentered
betweenthepanelmarkingsL andR.Ifyou
wishtoreducetrebleinrelationtobassfor
example,turntheTREBLECONTROLScoun-
terclockwiseuntilthetonebalancesounds
correct to you. These controls will modify
tonebalancewithoutintroducinganyunde-
sirableeffects.Donotbesurprisedifyou
findyourpreferenceintonechangingfrom
timetotime.
LOUDNESS
Duetoa selectiveshiftinsensitivityof
humanhearing,musicreproducedatvery
lowvolumelosesitsbassandtreble.
12

TheLOUDNESSswitchontheC22changes
theVOLUMEcontroltoa loudnesscom-
pensatedcontroltocorrectforthiseffect.
Whenyouwishtolistentomusicata greatly
reducedloudnesslevelandyethearbassand
trebleintheirproperrelationships,setthe
LOUDNESSswitchtotheINposition.
PHASE
Ifthestereosoundseemstocomefrom
eithersideoftheroominsteadofbeingdis-
tributedbetweentheloudspeakers,adjust
thePHASEcontrolto180°.Thislistening
effectisduetoreproducingsoundthatisout
ofphasefromonechanneltotheother.You
will find some records differfrom others in
this respect and that some tapes differfrom
records.
LISTENINGTOA STEREOTUNER
1.TurntheINPUTSELECTORtoTUNER
1orTUNER2.
2.TurntheMODESELECTORtoSTEREO.
3.SetthePHASEswitchto0°.
4.SettheH.F.cutofffilterswitchtoFLAT.
(Seepage12ADJUSTINGFORSPECIAL
EFFECTS.)
5.SettheRUMBLEfilterswitchtoFLAT.
(Seepage12ADJUSTINGFORSPECIAL
EFFECTS.)
6.SettheLOUDNESSswitchtoNORMAL.
(Seepage12ADJUSTINGFORSPECIAL
EFFECTS.)
7.TurntheBASSCONTROLSandTREBLE
CONTROLSsothattheindicatorsare
centeredbetweenthepanelmarkings
LandR.(Seepage12BASSANDTREBLE
CONTROLS.)
8.SettheTAPEswitchtoNORMAL.
9.AdjusttheVOLUMEcontroltothedesired
volume.
Aftera warmupofabout30seconds,turn
thetuningknobonyourtunertofindthe
stationofyourchoice.
LISTENINGTOA STEREORECORD
Tolistentostereorecords,proceedas
follows:
1.TurntheINPUTSELECTORtoPHONO1
orPHONO2,whicheverisconnectedto
thecartridgeyouwishtohear.
2.SettheMODESELECTORtoSTEREO.
3.SetthePHASEswitchto0°.
4.SettheHF cutoff filter to FLAT.(See page
12ADJUSTINGFORSPECIALEFFECTS.)
5.SettheRUMBLEfiltercontroltoFLAT.
(Seepage12ADJUSTINGFORSPECIAL
EFFECTS.)
6.SettheLOUDNESScontroltoNORMAL.
(Seepage12ADJUSTINGFORSPECIAL
EFFECTS.)
7.SettheTAPEswitchtoNORMAL.
8.SettheBASSCONTROLSandTREBLE
CONTROLSsothattheindicatorsare
centeredbetweenthepanelmarkings
LandR.(Seepage12BASSANDTREBLE
CONTROLS.)
9.AdjusttheVOLUMEcontroltothedesired
volume.
LISTENINGTOMONOPHONICRECORDS
Tolistentomonophonicrecords,proceed
asfollows:
1.TurntheINPUTSELECTORtoPHONO1 or
PHONO2,whicheverisconnectedtothe
cartridgeyouwishtohear.
2.TurntheMODESELECTORtoMONO
(L+R).
3.SetthePHASEswitchto0°.
4.SettheHFcutofffiltertoFLAT.(Seepage
12ADJUSTINGFORSPECIALEFFECTS.)
5.SettheRUMBLEfiltercontroltoFLAT.
(Seepage12ADJUSTINGFORSPECIAL
EFFECTS.)
6.SettheLOUDNESScontroltoFLAT.(See
page12ADJUSTINGFORSPECIAL
EFFECTS.)
7.SettheBASSCONTROLSandTREBLE
CONTROLSsothattheindicatorsare
centeredbetweenthepanelmarkings
LandR.(Seepage12BASSANDTREBLE
CONTROLS.)
8.AdjusttheVOLUMEcontroltothedesired
volume.
LISTENINGTOTAPEDECKS
Tolistentotapefroma tapedeck,proceed
asfollows:
1.TurntheINPUTSELECTORtoTAPEHEAD.
2.TurntheMODESELECTORtoMONO
(L+ R)orSTEREO,dependingonthe
programonthetape.
3.SetthePHASEswitchto0°.
4.SettheHFcutofffiltertoFLAT.(Seepage
12ADJUSTINGFORSPECIALEFFECTS.)
5.SettheRUMBLEfiltercontroltoFLAT.
(Seepage12ADJUSTINGFORSPECIAL
EFFECTS.)
6.SettheLOUDNESScontroltoFLAT.(See
page12ADJUSTINGFORSPECIAL
EFFECTS.)
7.SettheBASSCONTROLSandTREBLE
13

CONTROLSsothatthedialindicatorsare
centeredbetweenthepanelmarkings
LandR.
8.AdjusttheVOLUMEcontroltothedesired
volume.
LISTENINGTOA STEREOTAPEMACHINE
Astereotapemachinewithitsownplay-
backpreamplifiersshouldbepluggedinto
the AUX input orthe TAPE MONITOR input-
nottheTAPEHEADinput.
IftheTAPEinputisused,proceedasfol-
lows:
1.TurntheINPUTSELECTORtoTAPE.
2.TurntheMODESELECTORtoMONO.
(L+ R)orSTEREOdependingonthe
programonthetape.
3.SetthePHASEswitchto0°.
4.SettheHFcutofffiltertoFLAT.(See
ADJUSTINGFORSPECIALEFFECTS.)
5.SettheRUMBLEfiltercontroltoFLAT.
(Seepage12ADJUSTINGFORSPECIAL
EFFECTS.)
6.SettheLOUDNESScontroltoNORMAL.
(Seepage12ADJUSTINGFORSPECIAL
EFFECTS.)
7.SettheBASSCONTROLSandTREBLE
USINGTHEC22FRONT
Twotapemachinescanbeusedwiththe
C22StereophonicPreamplifier.Afteryou
haveconnectedyourtapemachinetothe
rearpanelofthepreamplifiersomeonemay
desiretobringi.na portablemachinetomake
acopyofoneofyourtapesortolistentoone
ofhistapesonyoursystem.WiththeC22you
nolongerhavetounplugyourpermanent
machine.TheC22issuppliedwithtwo
cables.Thecableshavephoneplugsonone
endtoplugintothefrontpaneloftheC22
andpinjacksontheotherendtopluginto
anytapemachine.(Adaptersareavailableat
anyHi-Firetailertopermitpinplugstocon-
nectwithphonejacks.)
Tolistentotheportableorsecondtape
machineplugthepinjackendofthetwoC22
cables,mentionedabove,intothetape
machineoutput.Connectthetelephone
plugsintothetelephonejacksontheC22
frontpanel.Theleftjacksuppliestheleft
channel.Therightjacksuppliestheright
channel.TurntheINPUTSELECTORswitch
toTAPE.WhentheTAPEJACKcontrolis
turnedtothePLAYBACKposition,the
permanenttapemachineoutputisdiscon-
CONTROLSsothatthedialindicatorsare
centeredbetweenthepanelmarkings
LandR.
8.AdjusttheVOLUMEcontroltothedesired
volume.
IftheAUXinputisused,turntheINPUT
SELECTORtoAUX;then,proceedthesame
asforTAPEinput.
1.SettheTAPEMONITORswitchtoMON-
ITOR.
2.TurntheMODESELECTORswitchto
MONO(L+ R).
3.SetthePHASEswitchto0°.
4.SettheHFcutofffiltertoFLAT.(Seepage
12ADJUSTINGFORSPECIALEFFECTS,)
5.SettheRUMBLEfiltercontroltoFLAT.
(Seepage12ADJUSTINGFORSPECIAL
EFFECTS.)
6.SettheLOUDNESScontroltoFLAT.(See
page12ADJUSTINGFORSPECIAL
EFFECTS.)
7.SettheBASSCONTROLSandTREBLE
CONTROLSsothatthedialindicatorsare
centeredbetweenthepanelmarkings
LandR.
8.AdjusttheVOLUMEcontroltothedesired
volume.
PANELTAPEINPUTJACKS
nectedfromtherearpanel.Theportable
tapemachineisnowconnectedandany
programoriginating in thismachine will be
heardthroughtheC22,andwillalsobe
availablefromtheC22TAPEOUTPUTto
drivethepermanenttapemachineinput.
Thisfeatureallowsyoutocopya tapefrom
theportablemachineintoyourpermanent
machine,providedyourpermanentmachine
hasitsownrecordingpreamplifier.
Torecordontheportablemachineplug
thetwophonopinplugsofthetwoC22
cablesintotheinputoftheportablemachine.
Leavethetelephoneplugsconnectedtothe
C22telephonejacksonthefrontpanel.
OperatetheTAPEJACKswitchtotheRE-
CORDposition.Thepermanenttapemachine
will be reconnected. Nowany program
pickedupbytheINPUTSELECTORswitch
willbeavailabletodrivetheportablema-
chine.Youcannowmakea copyonthe
portablemachineofanytapeplayedonthe
permanentmachine.Youcancopyanyother
programsourceontobothtapemachinesat
thesametime.
Whenrecordingfromonetapemachineto
14

theothertheonlycontrolthatiseffectiveis
theTAPEJACKswitch.(Note:Someportable
tape machines will drive theC22 eventhough
theTAPEJACKswitchisintheRECORD
position.)Thisisnota normalcircuituseand
adistortedsignalusuallyresults.Forlow-
distortionoperationfollowtherecommended
procedure.
USINGTHEC22WITHMICROPHONESFORSTEREO
Microphonesinstereomaybeusedwith
theC22.ThetwoMICchannelsamplify
microphonesignals.Theyhavea sensitivity
of2 millivoltsandaninputimpedanceof1
megohm.Forloweroutputmicrophonesin-
puttransformersshouldbeusedtoraisethe
voltageoutputtothe2 millivoltrange.
WhentheINPUTSELECTORisturnedto
theMICposition,theCOMPcontroldoesnot
operate.Alltheothercontrolsoperateand
maybeusedthesameasforanyother
programsource.
OPERATINGCURVES
15

Your C22 will give you many years of pleasant and satisfactory
performance.Ifyouhaveanyquestionsconcerningtheoper-
ationormaintenanceofthispreamplifierpleasecontact:
CustomerService
MclntoshLaboratoryInc.
2ChambersStreet
Binghamton,NewYork
Ourtelephonenumberis723-5491.
Thedirectdialareacodeis607.
GUARANTEE
MclntoshLaboratoryIncorporatedguar-periodof90daysfromdateofpurchase,
anteesthisequipmenttoperformasadver-Thisguaranteedoesnotextendtocompo-
tised.Wealsoguaranteethemechanicalandnentsdamagedbyimproperusenordoesit
electricalworkmanshipandcomponentsofextendtotransportationtoandfromthe
thisequipmenttobefreeofdefectsfora factory.
3-YEARFACTORYSERVICECONTRACT
Anapplicationfora FREE3-YEARFAC-finedinthe3-yearfactoryservicecontract.
TORYSERVICECONTRACTisincludedintheIftheapplicationisriotmailedtoMclntosh
pocketinthebackcoverofthismanual.TheLaboratory,onlytheservicesofferedunder
FREE3-YEARFACTORYSERVICECONTRACT the standard90-dayguarantee will apply on
will be issued by Mclntosh Laboratoryuponthisequipment. TAKEADVANTAGE OF3
receiptofthecompletelyfiledoutapplica-YEARSOFFREEFACTORYSERVICEBY
tionform.Thetermofthiscontractisde-FILLINGINTHEAPPLICATIONNOW.
InCanada:manufacturedunderlicenseby:
McCurdyRadioIndustries,Ltd.
22FrontStreetWest
Toronto,Canada
Designsubjecttochangewithoutnotice.
16

LABORATORYINC.
2CHAMBERSSTREET,BINGHAMTON,N.Y.
MadeinU.S.A.
Phone—AreaCode407-723-3512
Be122002
038-027