Audio Research LS27 Preamplifier audiobeat hi.pdfgo out of production, so let’s not count that as...
Transcript of Audio Research LS27 Preamplifier audiobeat hi.pdfgo out of production, so let’s not count that as...
Audio Research LS27 Preamplifier
by Dennis Davis, March 30, 2011 © www.theaudiobeat.com
othingshouldbesimplerthancomparinganew versionofanexistingproducttoitspredecessor, asitmakesthe“allotherthingsbeingequal”rulechild’splaytofollow.AudioResearch’sLS27linestageisjustonedigitremovedfromtheextremelysuccessfulLS26,whichIusedinmysystemfortwoyears--untiltheReference5tookitsplace.I’mnotadversetoeasyassignmentswhenthemenuincludessomethingastastyasanAudioResearchlinestage.Acomponentthat’spureplug-in-and-play,withnotoe-inorlevelingorbreak-in,leavesonlytheexerciseoftypingthereviewasachore.WiththeLS27,everythingprecedingthosekeystrokeswaspurepleasure.
TheLS27isAudioResearch’smiddle-rangelinestage,sittingbetweenthe$3995LS17andthe$11,995Reference5.(The$24,995ReferenceAnniversaryisaspecialeditionforasmallnumberofmogulsandlotterywinners.It’ssoontogooutofproduction,solet’snotcountthataspartoftheline.)At$6995,the
LS27isaseriouscomponentthataregularaudiophilecanaspiretoowningwithoutrobbingabank.ItupdatesthecosmeticlookoftheLS26’sfrontpanel,switchingoutblackforsilverhandles(thoughtheblackarestillavailable)ThereisalsoaDarthVaderversion:blackinallbutthebuttons.TheLS27alsoreplacestheoldersquare-buttonarraywithanewsetofroundbuttons,acosmetictouchfirstseenontheReferenceAnniversary.
Underthehood,thingslookverysimilartotheLS26,untilyoureyesstraytothebackofthecircuitboardandyounoticethattheunithasbecomealmostaninchandahalfdeeper.Thisisnotsurprising,astheLS26wasalreadypackedfullofcomponents,andtheLS27’supgradedparts
requiredadditionalbreathingspace.Bulkpower-supplystoragehasbeenincreased.Anewpowertransformeralongwithnewoutputandbypasscouplingcapacitorsaccountfortheaddedrealestate.Despitethesechanges,theLS27weighsinafew
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ounceslighterthanitspredecessor.ThestatedspecificationsoftheLS27,exceptforweightanddimensions,areidenticaltothoseoftheLS26.
LiketheLS26,itsreplacementremainsapureclass-Adesignwithzerofeedback.Ithasafullyregulatedsolid-statepowersupplyandahybridJFET/tubeaudiocircuitusingtwo6H30dual-triodesintheanalogstage.AswiththeLS26,ithasthreeselectablelevelsettingsforeachinput,witharecommendationthatthehighestsettingbeusedforbestperformance.IfoundthistobetoohighforanyofthecartridgesIuse,butthelowersettingsadjustforanyphonostage/cartridgecombination.
TheLS27alsosportsachoiceofbalancedorsingleendedinputsandoutputs,withatotalofeightinputchoices.Unlikewithmostlinestages,aright-leftbalancecontrol,aphaseinversionswitch,amono/stereoswitch,andatube-hourcounterarealsoincluded.Forme,abalancecontrolisessential,andIsuspectmostaudiophilesdonothavecustom-builtlisteningroomsthatneednotweakingofright-leftbalance.
AllofthesefunctionsmaybecontrolledwiththeubiquitousAudioResearchremote.TheLS27alsoincludesaprocessorpass-throughforhome-theateruse.AudioResearchstatesthatallofthesefunctionsarecontrolledbyanewmicroprocessor,althoughIcouldnotdetectanydifferenceinapplication.Indeed,withtheexceptionofthetube-hourcounter,IcouldcontrolallotherfunctionswhetherIwasusingtheLS26,LS27orReference5remote.Thatistosaythattheyallworkedflawlesslyandintuitively.
AudioResearchlongagodispensedwithattachedpowercords,andtheLS27hasa15-ampIECinlet.Ahigh-qualitypowercordshipswiththeunitforthosenotinclinedtobuyanadd-onpowercord.
ThelinestagearrivedfromAudioResearchwithabout200hoursloggedon.Beforelisteningtoit,Iranitinanother50hoursorsousinga
burn-inCD.AudioResearchnowpacksallofitstubeelectronicswithanoticethatthedevice
continuesbreakinginuntilsomewherearoundthe600-hourmark.Isuspectthatthisvariesbyunit,withthemoreexpensivemodelsandtheirlargercapacitorsbreakinginmoreslowly.IhavelistenedtootherAudioResearchmodelsstartingfromscratchandknowthatthebiggestchangesoccurinthefirstcouplehundredhours,soIfeltconfidentthatthisunitwasgoodtogoat250hours.Aftertheadditionalbreak-intime,IlistenedtoawiderangeofmusicbeforecomparingtheLS27toitspredecessor.
udioResearchlinestagesallshareaverystrong familysonicresemblance.Theyarealsothe productsofoneoftheindustry’smostconsistenttrickle-downprograms.EachnewReferencelinestageiseventuallyfollowedbyanewversionoftheLSlinestage,withthoseadvancesfromthetopmodelscaledbackandincorporatedintothemid-levelmodel.Sothoseaudiophileswhorefrainedfrommortgagingtheirhome
duringthereal-estatebubbletospringforaReference3waitedforthereleaseoftheLS26.NowtheLS27holdsoutpromisethattheReference5advanceshavetrickleddowntoit,notchingitupneartheperformanceoftheReference3(therewasno4,asitisconsideredanunluckynumberintheFarEast).
Amongtheirconsistentstrongpoints,AudioResearchlinestageshaveanuncannyabilitytoorganizemusicalinformationintoadeep,widesoundstage,especiallywiththebestofbothstereoandmonorecordings.Thesolidityand“youarethere”qualitiesoftheinstrumentswithinthatstageareequallyremarkable,andtheyhavedonenothingbutgetbetterbothwithintheAudioResearchrangeofproductsandviewedovertimeaseachnew
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generationofaparticularmodelappears.TheLS27isnoexceptiontothisrule.Whetherit’sreproducinglarge-scaleorchestralworkssuchasStravinsky’sFirebirdonMercury[MercurySR90226]orsmall-scalejazzensembleasexemplifiedbythestunningmonoreissueofKennyDorham’sAfro-Cuban[BlueNote/MusicMattersMMBLP-1535],thepreampwillthrowaslargeandrealisticasoundstageasyourcartridgeandphonostagecanpassontoit.
It’sthesolidityandfocusofimageswithinthatsoundstage,however,thatreallyseparatetheveryexpensiveunits,withmassivepower-supplypartsandultra-spendycapacitors,frommoreaffordablelinestages.TheLS27doesnotmatchwhattheReference5achievesinthisregard,nordoesanyotherpreamplifierinthispricerange.Theverybestunitscancastextremelyconvincingthree-dimensionalimages,inthesamewaythatadjustingthedepthoffieldofinacameraviewfinderwillcausetheimageto“pop”andtakeonathree-dimensionalquality.Youcan’tmakeasgoodanimagewithacheapTokinalensasyoucanwithtopLeicaglasswork,andthesamelimitationsapplytopreamplification.AudioResearchdoesnotmakeanyTokina-levelproducts,andtheLS27islikeagoodLeicalens,butnotthefastest-apertureversionofaparticularsize.Itcanproduceverystableimageswithinthesoundstage,ifnotachievethedivineresultsthataReference5canpulltogether.However,theLS27givesyouanawfullycloseapproximationofwhatAudioResearch’smuchmoreexpensiveReferencelinestagecandoundermostcircumstances.Onless-complexrecordedmaterial,thedifferencescanbesubtleindeed.
TheLS27performedbeautifullyinthefrequencyrangeofstringinstruments.IspentagooddealoftimelisteningtothenewCoupd’ArchetsetofviolinistJohannaMartzy’srecordings,The EMI Recordings[COUP16-23],andtheLS27performedbrilliantly.ItreproducedMartzy’suniquetone,whichisonthecoolside,withoutever
soundingharsh.ItcapturedthatcoolnesswhileatthesametimeplacedenoughairaroundtheinstrumenttomaketheserefurbishedearlyEMIrecordingssoundalmostmodern.Iplayedsome
ofthismusicforafriendanddidn’ttellhimthathewaslisteningtotheLS27insteadoftheReference5.Hewasagogatthebeautyoftherecordingandgavenothoughttotheequipment.
TheLS27wasalsoaccomplishedatrevealingsmallorlargechangesinotherequipmentinthechain.ItaccuratelycapturedthedifferencesinstringsoundbetweenLyraandKoetsucartridges,andIusedittodiscernandevaluatethedifferencesbetweenVPI’sSuper
Platterandstandard-issuealuminumplatter,andthenthedifferencesbetweenthealuminumplatterbare,witharubbermatandwithapapermat.TheLS27didnotobscureinanywaythedifferencesamongthesevariations.
ItalsowasachampatreproducingthebestofRudyVan
Gelder’sBlueNoterecordings.Theearliestoftheseareinmono,andanexceptionallinestagecanpresentanalmoststereo-likeimagewithnoneofthedrawbacksofearlystereo.KennyDorham’sAfro-Cubansoundedalarminglyreal.LiketheDorham45rpmset,AcousticSounds’remakeofNatKingCole’sgreatmonoalbumAfter Midnight[CapitolRecords/AnalogueProductionsAAPP782-45]alsothrewanincrediblemonosoundstagethatlackednothingwiththeLS27.That’snottosaythatitdoesn’tshowuptheimbalancesofpoorstereo.Itcertainlydidn’tglossoverthesedetails,anditlikewisedidn’ttampthemdown,assomeless-stellarlinestagescando.
omparedtotheLS26($5995),theLS27isdefinitely amoveupthespectrum,makingthatthousand- dollarincreaseinprice,alongwiththeimprovedpowersupplyandmoreexpensiveparts,whollyjustifiable.Iexpectedtheimprovementinsoundstagingsolidity,butIwasn’tpreparedforajumpintonalqualityandbass
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definition.However,withinminutesofaside-by-sidecomparisonofthetwounits,mylisteningpanelwaslikeagroupofOlympicjudges,declaringaclearwinfortheLS27becauseoftheseimprovements.ShelbyLynne’s“JustaLittleLovin’,”fromtheCDofthatname[LostHighway1744825],madeitclearthattheLS27hadtighteneduptheLS26’sbassand
refineditshighs.IneverconsideredtheLS26lackingintheseareasuntilthiscomparison.Extendedlisteningtothetwounitsconfirmedthisfinding,butshoweditwasmorepronounced
withsomerecordings,asIcouldnotreproducethesignificantdifferenceswithmostmaterial.OnoneofmyfavoritetestLPsforthequalityoftheupperfrequencies,SalvatoreAccardo’sDiabolus In Musica[DeutscheGrammophonDGG4776492],thedifferencesbetweenthewayinwhichthetwounitsinterpretedtheviolin,cymbalsandtriangleweresubtle,confirmingthattheLS26wasnoslouchinthisdepartment.Butwithafewmoderndigitalrecordings,suchastheShelbyLynne,theimprovementsinthenewunitwereobvious.
SimilarsubtleenhancementsweredetectedinareaswheretheLS26wasalreadyquitestrong.Bothunitshaveaverylownoisefloor,andthisgivesrisetoacuteretrievaloflow-leveldetailandnotableclarity.Likethepriormodel,theLS27soundedunforcedanddeliveredannaturalentréetotheflowofrecordedmusic--anuncommonabilityforallbutafewlinestagesinthispricerange.WhileIhadthebenefitofauditioningtheLS27withamuchmoreexpensivephonostage,IsuspectthattheLS27alongwithAudioResearch’snewPH8willbeamatchmadeinheaven. oifyoucan’taffordtoinvestmoremoneyin yourhi-fisystemthanyouhavetiedupinyour Maserati,theLS27maywellbetheidealheartofasystemyoucanlivewithforthelonghaul.It’sanextremelyversatileandmusicallinestagethatissurelyonetobeatinitspricerange.AudioResearchcontinuestopullonerabbitoutofthehatafteranother.
Price:$6995
Warranty: Threeyearspartsandlabor.
AudioResearchCorporation3900AnnapolisLaneNorth,Plymouth,Minnesota55447(763)577-9700
www.audioresearch.com
Associated Equipment
Analog:VPITNT-6turntablewithrimdriveandSDSspeedcontroller,VPI12.7tonearm,LyraSkalaandTitanMonocartridges,KoetsuCoralcartridge,AudioResearchReferencePhono2phonostage.
Digital:AudioResearchReferenceCD7CDplayer.
Preamplifier: AudioResearchReference5.
Power amplifier: AudioResearchReference110.
Loudspeakers:Kharma3.2withEnigmafilterandwiringupgrade.
Interconnects:NordostValhalla.
Speaker cables:NordostFrey.
Power conditioners:QuantumQBase8andQX4.
Power cords:NordostValhalla.
Equipment rack, platforms and accessories:BillyBagsequipmentrackmodifiedwitha4”mapleplatform,StillpointsUltraisolators,StillpointsComponentStands,FurutecGTXD-RhodiumACoutlet.
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