ALLNIC AUDIO L?1500 User manual




ALLNICAUDIO
L‐1500LINESTAGEPREAMPLIFIER
OWNER’SMANUAL

ALLNIC AUDIO
L-1500 LINE STAGE PREAMPLIFIER
ThankyouforpurchasingthisAllnicAudioL‐1500LineStagePreamplifier.
WearecertainyourtrustinAllnicAudioandHammertoneAudio,aswellas
yourappreciationforthesoundofthishigh‐qualitydevice,willbe
rewardedbyitsexcellentoperationforyearstocome.

PleasereadthisentiremanualbeforeyouconnecttheL‐1500Preamplifier
totheothercomponentsofyoursystemandthewalloutlet.
2

TABLEOFCONTENTS:
___________________________________________________________________
INTRODUCING THE L-1500 LINE STAGE PREAMPLIFIER 4
___________________________________________________________________
WHAT’S IN THE BOX? 5
___________________________________________________________________
SAFETY 5
___________________________________________________________________
CLEANING
Chassis
Connectors 5
___________________________________________________________________
INITIAL SET-UP
Location, Location, Location
Power Connection
Inputs
Outputs
Phase Switch
Remote Control 5
___________________________________________________________________
INITIAL POWER ON 7
___________________________________________________________________
OPERATION 7
___________________________________________________________________
TUBES 8
___________________________________________________________________
SPECIFICATIONS 8
___________________________________________________________________
WARRANTY 9
___________________________________________________________________
FIGURES 10

PleasereadaboutSAFETYbeforeyouattempttousetheL‐1500
Preamplifier‐wecareaboutourcustomersandtheequipment,andwe
wantyoutoenjoythisproductforalongtime!

3

INTRODUCINGTHEL‐1500PREAMPLIFIER

TheL‐1500isAllnicAudio’smid‐linepreamplifiermodel,
justunderthetopofthelineL‐4000.LikeallAllnicAudio
products,itusesPermalloy(Ironandnickelalloy)forits
transformercores.AllnicisgratefultoMr.G.W.Elmenof
WesternElectricforinventingPermalloyfortransformer
coreuse,andinsodoing,providinganenormousservice
torecordedmusiclistenerseverywhere.
TheL‐1500hasthefollowingfeatures:

•Singlegainstage–Asinglegainstagecircuituses
onlyonetubeforamplification(“gain”).This
reproducesapurer,moredetailed,morespacious
andmoredynamicsoundthanmultigainstages.

•Lineoutputtransformercoupling–TheL‐1500is
“transformercoupled”.Intubeampcircuitry,there
aretwocouplingmethods;oneiscapacitorcoupling
andtheotheristransformercoupling.Capacitor
couplingisthetraditional,lowcostmethod.Itis
somewhatstablebuttransfersonlyvoltage,not
wattage(i.e.,notrealenergy).Withtransformer
coupling,about90%ofrealwattageistransferred
(thereisstillatransformerlossofabout10%of
wattage–voltageisnotaffected).

Transformercouplingissuperiortocapacitor
coupling.However,alltheadvantagesof
transformercouplingdependonthequalityofthe
transformerandonthechoiceoftubes.AllnicAudio
manufacturesitsowntransformersanduseswhatit
viewstobethebestcorematerial,Permalloy.Allnic
Audio'sunprecedented,wide(16Hz‐75kHz,‐3db),
lowdistortional,andultra‐flexible(upto50kHz
squarewaveresponse)outputtransformerhelps
AllnicAudiotorealizetheidealtransformercoupled
preamplifier.Ofcourse,gaintubesarealsocarefully
selectedforthreecriticalfactorsforfunctionwith
thePermalloycoreoutputtransformers:highgm,
lowinternalresistanceandhighmu.

•Constantandlowoutputimpedance–Oneofthe
benefitsoftransformercouplingisthatitfacilitates
constantlowoutputimpedance.Lowoutput
impedanceiscriticaltothedesignofagood
preamplifier.TheL‐1500hasa150ohm(150Ω)constant
outputimpedanceatallfrequencies.Incapacitor
coupling(C‐Rcoupling),a“cathodefollower
circuit"isusuallyusedtoloweroutput
impedance.Unfortunately,thismethodof
loweringoutputimpedanceisaccompaniedby
highdistortionandhasan"L"shapedoutput
impedancecurve.Pleasecomparethetwographs
below,especiallyforlowfrequencyresponse.

•Advancedtubetechnologyvoltageregulation‐For
quieterandmoredynamicoperation,theL‐1500has
anultrahighspeedautomaticvoltageregulation
circuit,utilizingvacuumtubes.Thisalsoprotectsthe
amplifyingtubesfromchangeintheAClinesupply
andcopeswithanyabrupt,internalcurrentdemand.

•Newvacuumtubedampingtechnology–Allnic
Audio’spatented"AbsorbGELtubedamper"
technologypreventsharmfulvibrationsfrom
reachingthesignal/gaintubesand,therefore,
preventsmicrophonicnoisepropagationinthetubes.
TheAllnicAudioAbsorbGeldampertechnology
effectivelysolvesaproblemthatplaguesmosttube
amplificationsystems.Providedothertube
componentsdonotintroducemicrophonicnoiseinto
yoursystem,withtheAbsorbGeldampingsystem,
youwillenjoyadegreeoftransparentsoundthatwill
surpriseandpleaseyou.

•Precisionattenuatorvolumecontrol–TheL‐1500
doesnotemployadigitalICvolumecontroloralow‐
costcarbonfilmvolumecontrolwithamotor.Allnic
Audiohasdevelopedaprecisionoilclutched
motorizedattenuator;theL‐1500hasno(±0db)
channelunbalanceatanyvolumelevel.

•PureClassAoperation

•AsareallAllnicAudioproducts,theL‐1500isfully
RoHS(EUReductionofHazardousSubstances
regulation)compliantinconstructionandmaterials.
4

WHAT’SINTHEBOX?

Pleasecheckthattheshippingboxcontainsthefollowing:

•One(1)AllnicL‐1500preamplifier–innatural
aluminumorblack,dependingonyourorder
specification
•One(1)powercord
•One(1)Owner’sManual

Note:

1) TheL‐1500shipswiththetubesinstalled.
2) TheL‐1500willworkwithmostIECtype
aftermarketpowercords.Ofcourse,onlyyoucan
determinethepowercordthatworksmost
synergisticallywiththeL‐1500inyoursystem.

Weadvisethatyoukeeptheboxandotherpacking
materialsthatyourL‐1500camein.Itwillbeusefulifyou
sellyourL‐1500orintheunlikelyeventyouneedtoshipit
forservice.

SAFETY

•Disconnectthepowercordbypullingtheplug,not
thecable.
•Keepthepowercordawayfromanyheatsource.
•Keeptheunitawayfromliquids–donotallowany
liquidtoentertheinterioroftheunit.
•Whentheunitismovedfromacoldtoawarm
environment,allowsufficienttimeforany
condensationtoevaporatebeforepluggingtheunit
intoanACconnection.
•Donotattemptanyrepairs.
•Seethenoteson“Location,Location,Location”.
CLEANING

A. Chassisandglass

Useonlyasoft,lint‐freeclothdampenedslightlywith
wateronly(NOcleaningfluids!)tocleanthefaceplate,
meterglassandchassis.

B. Connectors

Youmayuseanygoodqualitycontactcleaner
recommendedforsuchapplicationstocleanthecontacts
fromtimetotimeasyoudeemappropriate.

INITIALSET‐UP

A.LOCATION,LOCATION,LOCATION

Likeallaudioproductsusingtubes,theAllnicAudioL‐
1500needstobeplacedonasolidstandinalocation
thatprovidesforgoodaircirculationaroundthe
preamplifier.

•DONOTcovertheventilationslotsinthetopof
thechassis.
•DONOTplacetheunitoncarpetorfoam.
•DONOTsubjecttheunittoknocksandshocksas
youmoveitaround.Thisadviceismeant
particularlyforthosewhomaywanttoplacethe
L‐1500onsomekindofafter‐marketisolation
feetorsimilardevices.Droppingonesideofthe


Output
Impedance
Frequency
(Allnic LCR Output Impedance Curve) Frequency
(Traditional CR Type Output Impedance Curve)
Output
Impedance
5

L‐1500,orthewholeunit,isnotagoodthingto
do.
•DONOTplacetheunitnearastronglightorheat
source.
•DONOTplaceanythingheavyontheunit.
•DONOTallowrubberorvinylmaterialstoreston
theunit’schassisforlongperiodsoftime.This
coulddiscolourthemetal.

•DOplacetheunitonashelforstandthatisstable
andnotsubjecttovibrationorsuddenshock.
•DOconsiderusingahighqualitypowercordand
inter‐connects,bothinputsandoutputs.TheL‐
1500isahighlysensitivepieceofelectronic
equipmentdesignedforneutralityandwilloutput
whatyouputintoit.
•DOtrytoplacetheL‐1500awayfrommajor
sourcesofRFIandEMI;thoughwellshielded,theL‐
1500willfunctionbestawayfromlargepower
transformersandothersourcesofsuch
interference.

B.POWERCONNECTION

TheL‐1500usesastandardthreeprongmaleIEC
connectionforACinput.Youneedtouseapowercordwith
afemalethreeprongIECconnectoratoneend.

TotheleftoftheIECconnector(facingthebackoftheunit
asinFigure1),thereisapoweron‐offswitch.Leavethis
switchintheOFFposition–thatmeanstheswitchis
pressed“down”atthebottom‐whileyoumakeallinitial
connections.

TheL‐1500youhavepurchasedissetinternallyforAC
110/120volt–60HZoperation.Thereisnowaytochange
thistoanotherACsettingwithoutreturnoftheunittothe
factoryforre‐wiring,attheowner’scost,including
transportbothdirections.

C.INPUTS

Therearefive(5)inputs.Line1andLine2arebalanced
connections(XLRtypeconnectors).Theremaining3line
inputsareRCAtypesingle‐endedconnections.Noneofthe
inputsisintendedespeciallyforconnectiontoany
particulardevice.
NOPHONOSTAGE‐TheL‐1500isalinestage
preamplifieranddoesNOThaveabuiltinphonopre‐
amplifiersection.Youwillneedaphonopre‐amplifierif
youwanttouseaturntablewiththeL‐1500.Youcan
connectyourphonopre‐amplifiertoanyofthefive
inputs,providedyouhavetheappropriatetypesof
connectionsoradaptors.

TheL‐1500hasbeendesignedandmanufacturedtowork
mostsynergisticallywithAllnicAudiophono
preamplifiers,pre‐preamplifiersandequalization
products.

D.OUTPUTS

TheL‐1500isequippedwiththreepairsofoutputs.Two
(2)oftheoutputsrequirebalancedconnectors(XLR
type);one(1)pairisunbalanced,usingRCAtype
connectors.

Oneofthepairsofbalancedoutputsisa“RecordOut”.It
isastraightpass‐through,isnotaffectedbytheL‐1500’s
circuitry,andprovidesnogain.

Theothertwopairsofoutputsareintendedfor
connectiontoapoweramplifier.OnthebackoftheL‐
1500thereisaswitchtoselecteitherbalancedorsingle‐
endedRCAconnectiontoyouramplifier.Theoutput
selectionswitchisjustbelowthePhaseswitch(seeFigure
1).Pleasesettheoutputselectionswitchtothetypeof
outputconnectionyouareusing.Ifyousettheswitchto
“balanced”andthenconnectyourcablestotheRCA
connections,audiblehumwillbeintroduced.

Youmayuseboththebalancedandsingle‐endedRCA
outputsatthesametime,forexample,ifyourunone
pairtoyourstereoamplifierandtheothertoa(orapair
of)poweredsubwoofer(s).Insuchacase,settheoutput
selectionswitchtounbalanced(RCA).Thiswillavoidthe
introductionofhum.

E.PHASESWITCH

Abovetheoutputselectionswitch,thereisaphase
switch.Thisswitchisa180degreephaseswitch;phaseis
eithernormalorinvertedonehundredpercent,
dependingontheswitchposition.Oninitialconnection,
settheswitchtonormal.Dependingonthephaseyour
6

sourcesoutputandtheirfacilitieswithregardtophase,you
maywanttoswitchtoinvertedphasesometimes.Phase
issuesgenerallywillresultinlackofbassand/orfocusof
thestereoimage.

REMOTECONTROL

Theremotecontrolprovidestheabilitytoremotely:

PowertheL‐1500onandoff(itisa“toggle”typeswitch)
usingthebuttonlabeled“POWER”.
Selectthelinesourceinputusingeitherthenumbered
buttonsortheupanddownarrowbuttonsaboveand
belowtheCHANNELlabel.
•Controlthevolumelevelusingtheup(louder)and
down(quieter)arrowbuttonsaboveandbelowthe
VOLUMElabel.
•MutethevolumeusingthebuttonlabeledMUTE,
locatedbetweentheCHANNELandVOLUMEarrow
buttons.DepressingthisMUTEbuttonwillrunthe
volumecontroldowntozero.Toraisethevolume
againaftermuting,presstheMUTEbuttontotake
thevolumeleveltowhereitwaspriortomuting.

INITIALPOWER‐ON

OnceyouhaveyourL‐1500inplace,allconnectionshave
beenmadetoyoursourcesandyourstereoamplifieror
mono‐blocksand/orsubwoofer(s),pressthepowerswitch
ontherearpanelofthechassistothe“on”position–that
meanstheswitchis“down”atthetop.

PLEASENOTE–CAUTION!

1)Youmayneedtodepressthepowerswitchonthe
rearofthechassisseveraltimes(wait30seconds
orsobetweeneachtry),fortheL‐1500topowerup
internally(beforeyouturnontheunitfromthe
frontpanelortheremotecontrol).Theboot
systeminsidetheunitneedstorecognizethe
remotecontrolandsynchronizewithit;thisiswhat
accountsforthepossiblenecessityofseveraltries
withtherearswitch.Whenthatoperationis
successful,theeventsdescribedjustabovewill
occur.Unsuccessfulboot‐upsmayresultinsomeof
thefrontLED’sglowingfaintlyifthepowerswitch
onthefrontpanelofthechassisisinthe“on”
position,butthismaybeignored.
2)Besureyouhavemanuallyturnedthevolume
controlonthefrontpaneltotheextreme
counter‐clockwiseposition(minimumvolume).
OPERATION

WhentheAllnicL‐1500haspoweredupinternallyand
youhaveeitherdepressedthefarlefthandbutton
marked“power”onthefrontpanel,orpressedthe
powerbuttonontheremotecontrol,thefollowingwill
happenonthefrontpanel:

Thelightabovethe“power”buttonwillilluminate.
Themeteronthefarlefthandofthefrontpanel,labeled
“current”willilluminate.Anyofthefivenumberedline
sourcelightsthataredepressedwillilluminate.After
aboutforty(40)seconds,thelightabovethe
“operate”/”mute”buttonwillilluminate.TheL‐1500has
a“softstart”delayforthetubesinordertoextendtube
life.

TheAllnicAudioL‐1500isnowreadyforoperation.At
thispoint,youcanpoweronyourstereopoweramplifier
ormono‐blocks.

Toavoidsurgestothespeakers,itisbesttochangefrom
inputtoinputonlywiththe“operate”buttonsettomute
(thelightabovethebuttonwillnotbeilluminatedwhen
thebuttonisinthe“mute”position).

Fromthispointon,operationisstraight‐forward.All
functionsarecontrolledfromthefrontpanelorthe
remotecontrol.Ofcourse,BECAREFULaboutdifferences
ingainbetweenyoursources.Generally,discplayersand
tunerswillhavegreatergainthanphono‐stages.That
meansthevolumesettingforlisteningtoyourturntable
mightbetoohighforlisteningtoCD’s.

Whenyouarefinishedlistening,turnoffyourstereo
poweramplifierormono‐blockamplifiers.Thenturnoff
theL‐1500,usingtheremotecontrolordepressingthe
powerswitchonthefrontpanel.Thepowerswitchon
therearpanelshouldstayinthe“on”position–thiswill
keepkeycircuitrywarm,andyourL‐1500willbereadyto
playwhenthesoft‐startturnsontheL‐1500nexttime
youwanttolisten.Turnoffyoursourceslast.
7

THECURRENTMETER

Thisilluminatedmeterindicatesthecurrentsupplytothe
gaintubesintheL‐1500.Itisanindicatoroffailureor
damagetothefunctionoftheunit.Theneedleshouldbe
betweenthetwoparallellinesjustleftofcentreonthe
meterface.AnyfailureofthetubesorcircuitsintheL‐1500
isindicatedbythemeterneedlemovingoutfrombetween
thesetwoparallellines.Youneedtoswitchthemeterand
checkbothchannelstoascertainwhathasoccurred(Use
thetoggleswitchlocatedonthebottomofthechassis,
behindthebottomleft‐handcorneroftheL‐1500front
panel,toswitchthemeterbetweentherightandleft
channels–toggletotheleftisleftchannelandvice‐versa).

Iftheneedlehasmovedtotheleftoftheparallellineson
onechannelonly,itmeansthattheE810Ftubeforthat
channelisfailing.
Iftheneedlehasmovedtotheleftoftheparallellineson
bothchannels,itmeansbothE810F’sarefailing.
Iftheneedlemovestotherightoftheparallellines,it
meansthatoneortheotherofthevoltageregulatortubes
(7233or6485)isfailing.Inthiscase,theneedlewillalways
betotherightoftheparallellinesonbothchannels.

Inthecaseofanyfailureindicatedbythemeter,please
contactHammertoneAudioforassistance.

TUBES

TheL‐1500usesthefollowingtubes(seeFigure4):

Two(2)xE810F
One(1)x7233
One(1)x6485

Allconsequencesofchangingorattemptingtochange
tubesarebornebytheuserunlessbyexpressagreement
betweentheownerandHammertoneAudio.AllnicAudio
andHammertoneAudioarenotliableinanyway
whatsoeverforanyinjuryorlossincurredbytheuserorfor
damagetotheL‐1500,anyofitsparts,ortubesor
replacementtubesresultingfromtheuserchangingor
attemptingtochangetubes.

SPECIFICATIONS
FORTHEALLNICAUDIOL‐1500LINESTAGEPRE‐
AMPLIFIER

Inputs:Linelevel×5pairs
(Balanced×2,Unbalanced×3)

Outputs:Balanced×1pair
Unbalanced×1pair

InputImpedance:Unbalanced10kΩ
Balanced20kΩ

FrequencyRange:20Hz~20kHz(FLAT)
16Hz~75kHz(‐3dB)

VoltageGain:+20dB

THD(1kHz):Output0.3V,0.06%
Output1.0V,0.15%

S/NRatio:90dB(CCIR,1kHz)

MaximumOutput:15VRMS(Non‐clipping)

OutputImpedance:150ΩConstant

PowerConsumption:30Wat110/120V/60Hz

Tubes:E810F(orD3a)×2(gainstage,
leftandrightchannels–there
arenoequivalentstothese
tubes)
7233(noequivalent)×1
(VoltageRegulator)
6485(similarto6AH6,6AH6WA,
6AH6S,CV2521)×1(Voltage
Regulator)

Fuse:AC3A,250V

Dimensions:430mm(16.9291inches)(W)
300mm(11.811inches)(D)
120mm(4.72441inches)(H)

Weight:9kg(19.8lbs)unpacked.
Shippingweightinoriginal
materialsis12.7kg.(28lbs)
8











WARRANTY

AllAllnicAudioamplifierproductsarewarrantedagainstmaterialsandmanufacturingdefects
forparts,excludingtubes,andlabourfortwo(2)yearsfromdateofpurchase.Tubesare
warrantedagainstmaterialsandmanufacturingdefectsforone(1)yearfromdateofpurchase.
Thewarrantyistransferableforthebalanceoftheoriginalpurchaser’swarrantyperiod,
provided,asstatedbelow,nounauthorizedrepairsormodificationshavebeenperformedon
theproduct.Dateofpurchaseisthedateindicatedontheinvoicefortheproductissuedby
HammertoneAudio.

Forthewarrantytobevalid,adefectiveproductmustbereturnedtoHammertoneAudiofor
servicepriortoanyunauthorizedattempttorepair.AnyrepairworkonanAllnicAudioproduct
notspecificallyauthorizedbyHammertoneAudiowillvoidthewarrantyontheproduct.























9

Figure1–L‐1500RearPanelView
Figure2–L‐1500RemoteControl
Figure3–L‐1500FrontPanelView



10



Figure4–L‐1500InternalView
11

12