VAC Phi Beta Triode Setup guide

TheVACPhiBeta
TriodePreamplifier
Operation&MaintenanceInformation
ValveAmplificationCompany
Manualissued02/15/2008

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CAUTION
THEPREAMPLIFIER ANDPOWER SUPPLYCONTAINPOTENTIALLYLETHAL VOLTAGES,AND
TUBESTHAT BECOMEHOT IN USE.
NEVER OPERATETHEPREAMPLIFIER ORPOWER SUPPLYWITHTHECOVERSREMOVED.
DONOT REMOVETHECHASSISCOVERSEXCEPT TOCHANGETUBESORLIGHT BULBS.
BEFORE OPENINGACHASSISTOCHANGETUBESORLAMPS,DISCONNECTTHEPOWER
SUPPLYFROMACPOWER ANDTHEAUDIOCHASSISFROMALL OTHER COMPONENTS.
ALLOWITTOSITTURNEDOFF FOR30 MINUTESBEFORE REMOVINGTHECOVER.REPLACE
COVER ANDSECURELYATTACHBEFORE RECONNECTINGANDOPERATING
DONOT OPERATETHEUNITSIF THEYARE WET.
VACUUMTUBESBECOME HOT ENOUGHTOCAUSESERIOUSBURNS.NEVER TOUCHATUBE
WHENTHEUNITISON.ITMAYTAKESEVERAL MINUTESFORTHETUBESTOCOOLDOWN
AFTER THEUNITISSWITCHEDOFF.ITISSTRONGLYRECOMMENDEDTHAT THETUBECOVERS
BELEFT IN PLACEAT ALL TIMES.
THEAMPLIFIER ANDPOWER SUPPLYARE HEAVY.ITISADVISABLETOHAVEASSISTANCEIN
UNPACKING,MOVING,ANDSETTINGUP.BESURE TOUSEPROPER LIFTINGTECHNIQUESTO
AVOIDBACKSTRAINANDINJURY.BECERTAINTOINSTALL ITINASECURE LOCATIONFROM
WHICHIT CAN NOT FALL ORTIPOVER.
CONTENTS
Introduction
Installation
Inputs(backpanel)
Outputs& Grounding Switch(backpanel)
Operation
Fuses
Front Panel Controls
RemoteControl
Replacement ofTubes
CareofChassis
A WordAbout Tubes InGeneral /Locating aDefectiveTube
Warranty /RegistrationForm

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INTRODUCTION
ThePhiBetaPreamplifieristheworld'sfinestaudio preamplifierand anabsolutely unique
component.Itsunusualtopology,premiumparts,and flexibilitymakeitapleasuretohear
and operate.
Thelinestageis,ineffect,asmall Class A1poweramplifier,capableofdriving loadsaslow
asafewhundredohms.Thisisastarkcontrasttonormalpreamplifiers,whichclaim alow
output impedancebut completely collapse whenaskedtodelivercurrent.ThePhicircuit
isloafingwith anormalloadinthe10,000 to200,000 ohmrange,deliveringaneffortless,
musical performance.
Thereisnoloopfeedbackand nocouplingcapacitorsinthelinesection.All active
elementsaretriodetubes,thepurest,mostlinearamplifying devices yetinvented.Output
matchingisaccomplishedbywayofsuperboutput transformers.Asasidebenefit,different
output groundingconfigurationsarepossible,optimizingperformanceintoeitherbalanced
orsingle-endedloads,and allowing ground loopsto bebroken.
Theoptionalphonostageuses triodetubes operatingwithout loopfeedback.Gainis
moderately high,with averylownoise floor.Lowoutput MC cartridges areaccommodated
bymeansofhighqualitymatchingtransformers,whichcontributevoltagegainwithout noise,
resulting indetail thatemerges from aremarkably darkand neutral background.
Remotevolumecontrol isimplementedviaamotorizedmechanicaldevice.Thisprovides
twomajoradvantages.First,thecontrol iscompletely intuitivetouse.Second,weavoidthe
sound degradationattendant with VCAs,transistorswitches,and switchedresistorarrays.
Eachchassisisfabricatedfrom non-magneticaluminum.Theseparatepowersupply allows
e.m.f.fields,switchingtransients,and mechanicalvibrationtobeisolatedfrom theaudio
circuits.
ThePhiBetaPreamplifierisdesignednotto thelatestfadbut to substance,forthehighest
possiblesound quality.Timespent familiarizingyourselfwith thismanualwill bewell
rewarded.

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INSTALLATION
1)Provideadequateventilation.
2)Do notoperateoncarpetorany othersurfacethatmight blockairflow.
3)Thechassiswill becomewarm innormal use.
4)Do notallowthechassistotouchanymetalparts,suchastheframeofanequipment
rack.Thismight createaparallelground path thatcoulddegradethesound ofyour
system.
5)Input connectionisviasingleendedRCAjacksorXLRjacks(whichcanbefrom
balancedorunbalancedsources).Fortheinputsthatcanaccept eitherXLRorRCA
connectors,besurethattheassociatedswitchissetcorrespondingly.Connectline
levelinputs(CD, Tuner,Tape,etc.)totheappropriateRCAinput jacksontherear
panel.Note:with theexceptionofPhono (whenfitted),all inputsare"linelevel."
6)Output tothepoweramplifiercanbesingle-endedonRCAjacksorbalancedon
XLRjacks,but notboth simultaneously.Theoutput modeswitchmustbesetto
matchtheconnectionsused.IMPORTANT:READTHESECTIONON"OUTPUTS&
GROUNDINGSWITCH."
7)Output toarecordingdevice(taperecorder,CDrecorder,etc.)maybeobtained
from the“TAPEOUT”jacks.Theadjacent switchfor“TAPEOUT”mustbesetto ON.
Ifyoursystem does nothavearecorder,thisswitchshouldbesetto OFF.
8)Foroptionalphonostageonly:Connectphonocables totherearpanelMM and/or
MC inputslabeled"Phono"(both maybeusedinthesamesystem,astheyare
switchedbyacontrol onthefront panel).Connecttheground wire(s)from the
turntable(s)orphonocable(s)tothe"Ground" terminalprovidedontherearpanel.
9)Connectthepowercablefrom thepowersupply tothepreamplifier.Besureto
inserttheconnectorproperly,and fully tightenthelocking screws.
10)Connectthepowersupply tothepowersourceindicatedontherearpanel,either
100,120,220,or240 voltsAC.Thevoltageissetatthefactory.Avoidpower
conditionersthatfloattheground pin.ALWAYSconnectpowercordtocomponent
beforepluggingitintoanACoutlet.Forbestperformance,trytoroutethepower
cordaway from signal cables.

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11)Pay close attentionto powerquality,and beawarethatdifferent powercordscan
alterthesound.Thepowersupply’sbacklitmetersshowvariationinpowerline
voltageasreflectedto theaudio circuitry.
12)12 volttriggersareprovidedforcontrol ofotheraudio components.

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INPUTS(backpanel)
Inputs#1,#2,and Cinemamaybeeitherunbalancedorbalanced.Three connectionsare
possible:
1)Singleendedsignal onRCA connector.Setadjacent switchto “RCA.”
2)Balancedsignal onXLRconnector.Setadjacent switchto “BAL.”
3)SingleendedsignalonXLRconnector.Setswitchto“BAL.”Alternatively,youmaysetthe
switchto “RCA”ifand only ifthesourceis“pin2hot.”
OnepairofRCA jacksaccommodatethemonitorreturnfrom atapedeck.Ifyoudo not
haveatapedeck,these jackscanbeusedasanadditionallinelevelinput.Ifusingthetape
outputs,theTAPEOUT switchmustbesetto “ON.”
Twophonoinputsareprovidedfor"MC" and "MM" cartridges.Theground leadfrom the
turntableshouldbeconnectedto thebinding postlocatedby these jacks.
OUTPUTS& GROUNDINGSWITCH(backpanel)
OnepairofRCAjacksprovidelineleveloutput toataperecorder.Thelevelofsignalisnot
adjustedbythevolumecontrol.Ifusingthetapeoutputs,theTAPEOUTswitchmustbeset
to “ON.”
TwosetsofRCAoutput jacksareprovidedasmainoutputstopoweramplifiers.Inaddition,
two pairofXLRjackscanbeusedto driveapoweramplifier.The“OUTPUT MODE”switch
mustbesetaccordingly.Only onemodemaybeused,i.e., youcannotmixbalancedand
single-endedpoweramplifierconnections.

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OPERATION
Turnthe"Volume"control fully counterclockwise.
Muteisautomatically engagedwhenswitching ontheunit.
Allowthepreamplifiertowarmup foraminutebeforeyouun-mutetheunit; failuretowait
cancause atransient tobesent throughyourpoweramplifierthatmight cause damageto
yourloudspeakers.
PLEASEREADTHESECTIONONFRONT PANELCONTROLSBEFORE USINGTHEPREAMPLIFIER.
Aswith all highfidelityproducts,thesound characteristicoftheVACchanges somewhat
asitwarmsup.Bestsound will beachievedafterabout 15 minutes ofoperation.
AnytimethatthePhiPreamplifierhasnotbeenusedforafewweeksthesound maybe
different.Thisisalsonormalforhighresolutionaudio equipment.Optimumsound should
returnafterafewhoursofoperation,preferably with anaudio signal.
NotethatalthoughyourVACSystemhasbeenrun for48 hoursatthefactory,itwill
continueto "break in" forapproximately 150 hours.Also beawarethatmany components
displaytheneedforanewbreak inperiodafterbeingtransportedinunheatedcargo
aircraft.
FUSES
Thefuse islocatedbehindinatrayabovetheACpowerconnector;thefuse carrier
containsthefuse being used,aswell asaspare.
For220 or240 voltoperation,please use a1.0amperefuse.For100 or120 voltoperation,
thefuse shouldbe2.0amperes.
Voltageconversionsmustbeaccomplishedatthefactoryorviatheimporterforyour
country.Please consultthefactory formoreinformation.

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FRONT PANEL CONTROLS
Althoughmostofthefront panelcontrols(Volume,Power,Mute)areselfexplanatory,VAC
hasoutfittedthisunitwith several advancedfeatures whichbearfurtherdescription:
Power:Turnstheunitoff and on.
Mute:Toggles betweenthe"Mute"and "Operate"condition.Whenmuted,the
indicatorlight isilluminated.
Tape:Thisswitchselectsbetweenthesignalcomingfrom themainselector(light
out)orthesignal connectedto the“TAPEIN”jacks(light on).
Cinema:Thisswitchselectsthesourceconnectedto the“CINEMA”input jacks.
Volume(switch):
Thisswitchallowsanyinput (except Phono)tobelevelcontrolled(VARor
variable)bytherotaryVOLUMEcontrol,ortobeproducedataSET(fixed)
level.To setthisfunction,hold thetoggleswitchinthedirectionofthe
desiredsettingforfiveseconds,until theindicatorlight changes from blinking
to solidillumination.
IntheVARIABLEmode,thePhi functionsasaconventional preamplifier.
TheSETmodeallowsthecontrol ofvolumetobedeterminedentirely bythe
sourcecomponent.ThisisusefulwhenthePhiBetaPreamplifierisbeingused
asanelement ofamultichannelorhometheatersystem,with thelevelofall
5.1channelsbeing setby theplayerorthedecoder.
TheSETmodemayalsobeusedwith,forexample,aCDplayerthathasits
ownvolumecontrol.Inthisway,thePhi’svolumecontrol isbypassed.Some
audiophiles wouldconsiderthisto bea“hotrod”mode.
Note:TheTapeMonitorinput takes thesamesetting asthesourceinput.For
example,iftheSELECTORisoninput #1and #1issetup inaSETmode,
whenyouengagetheTAPEmonitoritwill alsobeintheSETmode,and the
VOLUMEcontrol will notchangethesound level.Conversely,ifinput #2isin
theVARmode,thentheTAPEmonitorwill alsobeintheVARmode,and the
volumecontrol will function. Therefore,itissuggestedthattheinput be
configuredto VARbeforerecording and monitoring isstarted.

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Phono:SelectsbetweentheMM and MC inputs.Overall phonofunctionisselected
with themainSelectorswitch(phonoisoneclickcounterclockwise from “1”
oroneclickclockwise from “6”).
PH1 istheMC phonoinput.Ithas64 dBofgain,makingitsuitableformost
lowoutput cartridges.
PH2 istheMM input,whichprovides 44 dBofgain,suitableforuse with MM
(moving magnet)and many high-output MC (moving coil)cartridges.
Optionally,PH2 may beasecond MC input.
Both PH1 and PH2 maybeconnectedinthesamesystem,sothatinessence
therearetwo phono inputs,selectablefrom thefront panel.
Selector:ThisswitchselectsbetweenIN1throughIN6and thePHONOinputs.Rotate
counterclockwise to movedownthroughtheinputs,clockwise to moveup
throughtheinputs.
Volume:Controlstheoutput levelforthePHONOinput,and any lineinput setto the
“VAR”LEVELmode.Note:itispossiblethatoneorboth channelsmaynot
shut off completely inthefully counter-clockwise position,and thatchannel
balancemay skewatwhisperlevels.
Meters:Indicatetheoperatingvoltages withintheunit.Thiswill varysomewhatdue
to fluctuationsinpowerlinevoltage.

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REMOTECONTROL
Theremotecontrol allowsforwireless adjustment ofPOWER,SELECTOR,TAPEMONITOR,
CINEMA,MUTE,and VOLUME.
Theremotewand ispoweredbytwo"AAA"batteries.These shouldbeofthealkalinetype.
Youwill needtoinstall theminthewand beforeusingtheremote.Sincebatteries canleak,
theyshouldberemovedfrom thewand ifitisnotgoingtobeusedforanextendedperiod
oftime.
Besureto observethepolarity diagram insideth battery compartment.