VAC ?200 Phi Two Hundred Setup guide

F 200
TheVACPhi Two Hundred
Stereo BeamPower Amplifier
Operation&MaintenanceInformation
Valve Amplification Company
Manual issued01/02/2009
Revised 03/11/2009, 01/21/2010

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CAUTION -SAFETYNOTICES
THEAMPLIFIERCONTAINS NOUSERSERVICEABLEPARTS.DONOT REMOVETHEBOTTOM PLATES
ORCHASSIS COVERS.LETHALVOLTAGESAREPRESENTWITHIN THECHASSIS.DONOT OPERATE
THEUNITSIFTHEYAREWET.
VACUUMTUBESBECOME HOT ENOUGHTO CAUSESERIOUSBURNS.NEVERTOUCH ATUBEWHEN
THEUNITIS ON. ITMAYTAKESEVERALMINUTESFORTHETUBESTO COOLDOWN AFTERTHEUNIT
ISSWITCHEDOFF.ITIS STRONGLY RECOMMENDEDTHATTHETUBECOVERSBELEFTIN PLACEATALL
TIMES.
Never touchatubeiftheglass isbroken.Theinternal structurescarryhighvoltageandcouldpresent
aserious,possiblylethal shock.Ifatubebreaks,unplugtheamplifier andwait30 minutes,then
removethetube.
Keepflammable objectsawayfrom theamplifier.
DONOT LEAVETHEAMPLIFIER UNATTENDED IN OPERATION.
THEAMPLIFIERIS HEAVY.ITIS ADVISABLETO HAVEASSISTANCEIN UNPACKING,MOVING,AND
SETTINGUP. BESURETO USEPROPERLIFTINGTECHNIQUESTO AVOIDBACK STRAIN AND INJURY.
BECERTAIN TO INSTALL ITIN A SECURELOCATION FROM WHICH ITCAN NOT FALL OR TIPOVER.
Provideadequateventilation -allow atleast3inches aboveandto eachside.
Donot place inacompletelyenclosed cabinet.Donot stackother equipment on topof theVAC
unit.
Donot operateon carpetoranyother surface thatmight blockair flow.

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INDEX
Introduction
Installation -Stereo
Mono Connections/ Mono Switch(option)
Operation
Installing New Output Tubes
Biasing &Checking Output TubeCondition
Replacement of Low Level Tubes
Care OfChassis
Tips andAdvice
A WordAbout Tubes inGeneral
Output Tubes
Low Level Tubes
Impedance Matching
Grounding
Tuning YourSystem
Specifications
Footnotes
Warranty&Registration Form

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INTRODUCTION
ThePhi200 isauniquepoweramplifier,andoneof themostvividanddetailedinVAC’s history,
secondonlyto thelarger Phi300.1.Featuringanewdirect-coupledinput &driver circuit,extremely
fastandvividsoundisachievedfrom both single-endedandbalancedsources.
ThePhi200 maybeused as a100+watt/channel stereoamplifier,orcanbeconnectedas a200+
watt monophonic amplifier.
ThePhi200 isdesignednot to thelatestfadbut to substance,forthehighestpossible soundquality.
Timespent familiarizing yourselfwith thismanual will bewell rewarded.

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INSTALLATION -STEREO USE
01)Install thevacuumtubes.Eachtubeoritsboxhas a“V” number,whichcorresponds to the
labels on thetopplateof theamplifier;these indicatewhere eachtubeshouldbeinstalled.
Fiteachtubeinto thematching socket.
Wheninserting andremoving tubes, handle them bytheir bases, not bytheir glass bulbs.
Notethatthere isalocatorpinon theoctal (eight contact)tubes thatindicates proper
alignment.
02)Connectinput cables,either RCA types forunbalancedsources,orbalancedXLRtypes for
balancedsources.
03)Verifythatthetwo“Balance /Single-Ended”switches are setto thesamedesiredposition.
Settheinput typeswitchto XLR (forbalancedinput)orRCA (forsingle-endedinput).
04)Ifyouramplifier isfittedwith aMONOSWITCH, ensure thatitissetto “STEREO”.
05)Connectthespeaker cables;theblackleadgoes to “-“ or“Ground”.Theredleadgoes to
“+” or“Positive”.Followthelabels fortheimpedance thatbestmatches yourloudspeakers.
06)Connecta12 volttrigger cable into thesocketon thebackpanel ifdesired;thisallowsthe
amplifier to beturnedon andoff byanexternal device.
07)Provideadequateventilation -allow atleast3inches aboveandto eachside.
08)Donot place inacompletelyenclosed cabinet.Donot stackother equipment on topof the
VAC unit.
09)Donot operateon carpetoranyother surface thatmight blockair flow.
10)Thechassis will becomehot innormal use.
11)Donot allowthechassis to touchanymetal parts,suchas theframeof anequipment rack.
Thismight createaparallel groundpath thatcoulddegradethesoundof yoursystem.
12)Connectthepower cordto thepower source indicatedon therear panel (will beeither
100,120,220, or240 voltsAC).Voltageconversionsmustbedoneatthefactoryof by
anauthorizedVAC importer.
13)Avoidpower conditioners thatfloatthegroundpin.
14)Power requirementsare approximately600 watts.Payclose attention to power quality,and

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beaware thatdifferent power cords canalter thesound.
15) Checkthebiassettingsof theoutput tubes whentheunitisfirstinstalled andwhenever a
tubeischanged.Itisalsoagoodidea to verifythesettingsperiodically,suchas once a
week. Follow thebiasprocedure outlinedlater inthismanual.
NOTES:
Donot removeandconnectinput cablesorspeaker cableswhile isamplifier isrunning.
Doing sorisksdamageto yourloudspeakers ortheamplifier.
Donot operatetheamplifier without aloudspeaker orloadresistorattached.
Donot allow anything to touchthetubes innormal operation -theybecomeveryhot.
Takecare to keepeveryone,especiallychildrenandpets,frombeingable to reachand
touchthetubes, whichbecomeextremelyhot andcause seriousinjury.
Never touchatubeiftheglass isbroken.Theinternal structurescarryhighvoltageandcould
present aserious,possiblylethal shock.Ifatubebreaks,unplugtheamplifier andwait30
minutes, thenremovethetube.
Keepflammable objectsawayfrom theamplifier.

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MONOCONNECTION - with Mono Switchoption
For200+watt mono operation:
1)SettheMONOSWITCH to “Mono”.
2)Ensure thatthetwoBALANCE/SEswitches are setidenticallyto oneanother.
3)Connecttheinput cable to either XLRconnector(balancedsource) orto either RCA
connector(unbalancedsource).
4)Connectthenegativespeaker leadto either “COMMON”binding post.
5)Connectthepositivespeaker leadto the“4-8"bindingpostassociatedwith theCommon
postselectedinstep4.Inmono operation,thiswill matchwell with speakers rangingfrom
approximately2to 8ohms.
6)Donot use the“1-2"or“2-4"binding posts.
MONOCONNECTION - without Mono Switchoption (earlyproduction units)
For200+watt mono operation:
1)Connectidentical input signals to thetwoinput jacks. Itispossible to use a“Y”adapter to
dothis, orwith twocablesifyourpreamplifer has twopairs of outputs.
2)Connectajumper wire betweenthetwobinding postslabeled“COMMON”.
3)Takenoteof yourloudspeaker’s impedance.Ifitis4or8ohms,connectajumper between
thetwobindingpostslabeled“8OHMS”;ifitis2ohms,connectajumper bewteenthetwo
binding postslabeled“4OHMS”.
4)Ifyourspeaker is4or8ohms,connectitto theCOMMONand8OHMbindingpostsof
either channel;ifyourspeaker is2ohms,connectitto theCOMMON and4OHMbinding
postsof either channel.
5)Ensure thattheBALANCE/SINGLE-ENDED switches are setidentically.

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OPERATION
Power on earlyunitsisappliedwith afront panel pushbutton switch.Notehowyou are pushing
thebutton if‘contactbounce’occurs, andyou’ll soon acquire areliable technique.
Power on later unitsisappliedthroughafront panel rocker switch.
Soundwill beginapproximately45 seconds after turnon.
Aswith all highfidelityproducts,thesoundcharacteristic of theVAC changes somewhatas itwarms
up.Weadvise againstleavingtheequipment on atall times forsafetyreasons,andbecause of the
attendant acceleration of output tubewear andpower consumption.Lifeof theoutput tubes
averages 3,000 to 8,000 hours.Forbesttubelife,turntheamplifier off whenyou are not listening.
AnytimethattheVAC Power Amplifier has not beenused forafewweeksthesoundmaybe
different.Thisisalsonormal forhighresolution audioequipment.Optimumsoundshouldreturnafter
afew hoursof operation, preferablywith anaudiosignal.
Please notethatalthoughyourVAC Systemhas beenrunfor48 hoursatthefactory,thebreak-in
timeof highresolution audioequipment isinfuriatinglylong. ThePhisoundwill continueto season
forapproximately200 hours.Theearlysoundof theamplifier will beless extended,dynamic,and
coherent.Thenthesoundwill improvenoticeably,followedbyaperiodof darker sound,finally
giving wayto thedesiredmusicality. Patience isavirtue.
Alsobeaware thatmanycomponentsdisplaytheneedforanewbreakinperiodafter being
transportedinunheatedcargoaircraft.

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INSTALLINGNEW OUTPUTTUBES
First, see theSAFETYNOTICEearlier inthemanual.
Output tubes are typeKT88.Replacement outputtubes shouldbepurchasedfromVAC. Itis
desirable thattubes beinmatchedquartetsforeachchannel,andbeclose to the"bogey"values
forthemajorparameters. Makecertainthateachtubefitsfirmlyinitssocket.
ALL POWERMUSTBEOFF.Waituntil theoldtubes havecooleddown(TUBESBECOME HOT
ENOUGHTO CAUSESERIOUSBURNSWHENIN OPERATIONANDMAYTAKESEVERALMINUTESTO
COOLDOWN).Install thenewtubes firmlyandfullyinthesockets,observingthatthetubewill only
fitinto thesocketinoneorientation,determinedbytheplastic “keyway”inthecenter of thebase.
Donot use excessiveforce. Replace thetoprods before operating theamplifier.
Adustthebiascontrolfullycounterclockwise.
Switchon theamplifier andfollowthebiasprocedure outlinedlater inthismanual.Biasmustbe
checkedandadjustedwhentheamplifier firstturnson,at60 seconds,90 seconds,twominutes,
andfiveminutes.Intheearliestchecks,setthebiassothatthemeter readabitto theleft of center.
Final setting shouldbemadeafter 15-30 minutes. Rechecknew tubes dailyforthefirstweek.
Whenever atubeischanged, thebiassettingsmustbecheckedand adjusted.
Aslight violetglowinthetubeisnot cause forconcern.Ifatanytimetheplate(theoutermostmetal
structure) of theoutput tubes beginsto glowbright orangeorredSWITCH OFF IMMEDIATELY (a
small area with adull orangeglowisnormal forcertainversionsof theKT88).Theredglowindicates
thatthetubeis"runningaway",being destroyedbyconducting excessivecurrent.Tubes mayrun
awayforseveral reasons:
1)Thetubeisnot fullyinsertedinthesocket.
2)Thetubefitslooselyinthesocketand thuscannot makecorrectcontact.Suchatubeis
unusable.
3)Thetubeisdefective.
Intheevent thattrouble isencounteredcheckconnectionsand/ortryanother tube.Stopifthe
problem persistsandconsultwith yourdealer orVAC.
Forfurther information,refer to Tips &Advice:Tubes inGeneral andTips &Advice:Output Tubes.

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CHECKINGOUTPUTTUBECONDITION
Thecondition of eachindividual KT88 output tubeshouldbecheckedwith thebuiltinindicatorLED
lights, locatedbehindeachKT88.
Proper settingisindicatedbyanLEDthatisdarkwhenno music isplaying, but lights‘with thebeat’
as music isplayed.Toachievethissetting, place theprovidedadjustment screwdriver inthebias
adjustopeningforthetubeto beset.While watchingtheassociatedLED, turnthecontrolclockwise
until theLEDlights;thenturnthecontrolslightlycounterclockwise until theLEDjustgoes out.Be
certainto stopthemusic before making thereading.
Repeattheadjustmentsifnecessary, as thetubes interactslightly.
DoNOT touchthetubes themselves, as theyare hot enoughto cause seriousburns.
NOTE:Someversionsof KT88will evidence adull orangeglowover asmall percentageof the
tube’s anode(see photo).
OutputTube Bias Adjustment:
Biassettingsitshould be checkedwhenyouinstall youramplifierand
approximatelyonce everymonththereafter.Itmustalsobe adjustedeachtime
atube isreplaced.
Allow theamplifier toreachnormaloperatingtemperature(abouttenminutes
ofwarmup should be sufficient).Mutethepreamplifierand setthebiasforthe
four KT88 tubesby referencingtheamber LEDlightsbehind eachtube.
Usingthesuppliedtool(orasmall flatbladedscrewdriver),rotateeachcontrol
in turnclockwiseuntil theassociatedLEDjustlights,thenbackup slightlyuntil the
lightjustgoesout.
Since theadjustmentscaninteractslightly,recheckall four tubes.