Audio Research Reference 150

Stereo Amplifierby Dennis Davis, March 1, 2012

© www.theaudiobeat.com

udioResearchhasseensomedramaticchanges overthepastfewyears.In2008,Quadrivio SGR,aprivate-equityfirmthatalreadyownedSonusFaberthroughitssubsidiaryFineSoundsSPA,acquiredthevenerableelectronicscompany.FineSoundsthenpurchasedWadiaDigitalinlate2010,combiningunderonevirtualroofthespeakercompany,thedigitalmanufacturerandthevenerablemakeroftubedelectronics.Then,inDecember2011,companyfounderWilliamZaneJohnsonpassedaway.

AudioResearchisoneoftheoldesthigh-endaudiocompaniestosurviveintothe21stcentury.Foundedin1970,thecompany’stubeequipmentwasalreadyiconicbeforeDaveWilsonbuilthisfirstspeaker,whenHarryWeisfeldwasbestknownfortheVPIBrick,andwhenthenameKrellreferredonlytoanextinctraceofadvancedbeingsfrom

theplanetAltairIV.Yet,throughalltheseyears,AudioResearchhascontinuedtogrowandthrive,maintainingacoresetofemployeesandneverrestingonitslaurels.Ifanything,theacquisitionofthecompanybyFineSoundsseemstohaveenabledtheprocessofinnovationtocontinueatafasterpace.Likeanycompanythatcontinuestogrow,AudioResearchmustdealwiththetensionbetweendeliveringproductsthataconsumer

canbesatisfiedwithoverthelonghaulwhileatthesametimestrivingtolookforwaysofconstantlyimprovingitsbrand.

AudioResearch’scurrentwaveofnewofferings(anditis

averitabletidalwave)islargelyinspiredby

theinnovationsdeveloped foritsultra-expensiveReferenceAnniversarypreamplifier,alimited-editiontwo-chassisdesignthatcelebratedthecompany’s

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40thanniversary.Thecompanyhasextractedthoseelementsfromitssuperhigh-endpreamplifierthatcouldbeincorporatedintotherestofitsReferencelinewithoutbreakingnewpricebarriersforthoseproducts.Asaresult,AudioResearchisreplacingallofitsReferencemodels,excepttheCD8,withnewmodels,allincorporatingasimilarsetofupgrades.TheReference110stereoampwasreplacedwiththeReference150,theReference210monoblockswiththeReference250s,andtheReference610TswiththeReference750s.BoththeReferencePhono2andtheReference5havebeenreplacedwithnewmodelsdesignated“SE”for“SpecialEdition.”WhilenotalloftheReferenceAnniversary’sinnovationscouldbepackedintoeachoftheseproducts,it’sclearthataconsistentthemeisincreasingthepower-supplysectionsofeachnewunitandupgradingcriticalcomponents.

ThenewReference150hasexactlythesameexternaldimensionsastheReference110.Aesthetically,theonlyrealchangeisthedefaultshifttoauniformcolor.TheclassicAudioResearchlookincludedasilverfrontpanelwithablackframeandblackhandles.Thenewmodelshavefrontplate,frameandhandlesallinsilverorallinblack(althoughthecustomerretainstheoptiontomixandmatchcolorstoachieveamoreretrolookifthat’swhatheseeks).Nomatterhowyoumixcolors,however,AudioResearchisstickingtoitsclassic“rack-mountwithhandles”look,which,giventheweightofthepackage,isprobablyagoodthing.TheReference150weighsinat75pounds,about8morethantheReference110.

WhatwouldadesignerlikeDeiterRams(responsibleformuseum-gradeindustrialdesignsforBraunelectronics,whichlater

inspiredSteveJobsatApple)havewrappedarounda75-poundhunkofmetalfilledwith

hot,glowingtubes?RamsandJobsweredealingwithrelativelysmallandlightweightdevicesthatrequiredlittleheatdissipation,allowingtheuseofplasticsand

fluidcasementlines.Whilesomemoderndesigners(mostlyItalian)havetriedtobringthisaestheticto(usuallymuchlighterweight)tubedesigns,tomethesedesignsfeelforcedandinstantlydated.SleekPininfarinalinesandblocksofcarvedaluminumaretheterritoryofsolid-statedesigns.

Withlargetubeamplifiers,theneedforasturdyframereallyleavestwochoices:afullyenclosedboxdesign(liketheAudioResearch)oralower-profile

boxwithprotrudingtubesandtransformers.I’mhappywiththeclunkyclassicindustrialdesign,softenedbyabitofroundingandbeveling,usedbyAudioResearch.Ialsoapproveofthemoveawayfromblackhandlesandcases,whichalwaysremindedmeofrack-mountedsupercomputersfromthe1960s.

WhileoutwardlytheReference150appearslittledifferentfromitspredecessor,severalchangesareimmediatelyobviousonceyoulookinside.WithmyownReference110onhand,side-by-sidecomparisonwaspossible.ThealreadylargetransformersusedintheReference110haveswolleninsize,accountingformuchofthenewamplifier’sincreasedweight.Thenumberofelectrolyticstoragecapacitorsinthepowersupplyhas

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doubled,withtwobanksofadozeneachintheReference150.Theaddedbankismountedtoaverticalcircuitboardatthefrontoftheunit.AudioResearchclaimsthatthetotalstorageisnow1040joules.ThenewinterstagecouplingcapacitorsappeartohavebeeninjectedwithsteroidscomparedtothoseintheReference110.Theresistorcomplementhasalsobeenmodifiedwithwhatappearstobethelargest-valueresistorsreplacedwithtwosmallerresistorsinparallel.

Butwhatisprobablymostobviousistheswitchfrom6550CpowertubesovertoKT120s.AudioResearchhadalreadybeguntheswitchtoKT120swithlate-productionReference110s,andhasincorporatedthischangeintothenextgenerationofitsamplifiers.ThepublishedspecificationsclaimasignificantincreaseinpowerbandwidthfromtheReference110’s12Hz-60kHztotheReference150’s5Hz-80kHz.

Likeitspredecessor,theReference150isfancooledusingapairoffans,whicharenowchassis-mountedonrubbergrommets.ThenewfansarenoticeablyquieterthanthoseintheReference110,inpartbecausetheyliterallystickoutthebackoftheamp.IopenedupbothunitstomakesurethatIhadthefanssettothehighestofthethreeavailablespeeds.WhiletheReference110’snoiselevelwasnotobtrusive,itwasclearlyaudible.Thenewlow-noisefanarrangementfortheReference150ismuchquieter.Ihadtoputmyearclosetotheamptohearanynoise,evenwiththefanssettothehighestspeed.

Whychooseastereoampratherthanapairofmonoamplifiers?Isupposeifspaceandfinancialconsiderationswerenotinvolved,audiophileswouldalwaysgravitatetomonoamps.AudioResearch’snext

stepupintheReferenceseriesisapairofReference250s.WhileI’venotyetheardthemoutsideshowconditions,Ihavelittledoubt

thattheywilldeliverevenmoreofwhattheReference150provides--butatasignificantcost

premium.Andwithtwoboxesdemandingtwicetherealestate,noteveryonecantakethisroute.Inanyevent,a150Wpcampispowerfulenoughtocomfortablydrivemostspeakersthatcanbemovedintomosthomesthatlackaloadingdock.

hentheReference150landedonmy doorstep,itwasnicelyburnedforabout 475hours,allowingforimmediatetesting.ThefirstthingIlistenedtowasaTownesVanZandtsong,“Waitin’‘RoundToDie”fromHeartworn Highway[HacktoneVJCD167],acollectionofvintagerecordings

froma1975documentarythatwasfirstreleasedonCDintheUKin2006.Iwastippedoff

tothisreleasebymyUKconnection,fellowTABcontributorRoyGregory,andquicklyorderedacopyfromtheUK(it’snowavailableonCDandvinylfromtheusualsuspectsintheUS).I’veheardthiscutonvariousiterationsofmyownhomesystem,onfriends’rigsandoninnumerablesystemsateveryCESandRockyMountainAudioFestoverthelasthalf-decade.There’snothingshowyaboutit,justTownesinhiskitchenwithhisguitar,afemaleguesthumminginthebackground,andadog.Therecordinghasatmospheretospare,andiftheequipmentisuptoit,it’soneofthemostrealistic-soundingrecordingsaround.I’velistenedtoitonwell-set-upsystems

employingcomponentsfarmorecostlythanmostaudiophilesgetachanceto

audition,letaloneown,soIknowwhatgoldliesburiedinthosedigitalpits.TheReference110alwaysfellabitshortofcapturingthesubtleacousticnuancesIknewtobethere,nomatterthespeakersitwaspairedwith.TheReference150createdamoredetailedsoundstageandcapturedauralcuesthataddeduptoexquisiteresolution.

AudioResearchequipmenthasalwaysbeenknownforcreatingalargeandwell-definedsoundstage.

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TheReference150tookthistoanewlevel.Thinkofthesoundfieldasacubemadeupofaninfinitenumberofbits,likethescanlinesonavideoscreen,onlyinthreedimensions.Morebitsofinformationinthatspacegivegreaterweightandtexturetoeverythinginthesoundfield.The150justseemedtohavemorebitsineachofthethreedimensions.Asaresult,thestagedepthofthe110wasslightlycollapsedcomparedtothatofthe150,especiallywithrecordingslikeHeartworn Highwaythatofferrealisticstagedepth.Notonlydoesthisallowyoutobetterplaceaparticulareventwithinthesoundstage,butalsotheimagewithinthatspecialcontexthasmoretextureandthereforelessgrain.VanZandt’svoice,scarredbyyearsofsubstanceabuse,healthproblemsand,inthisinstance,apremium-gradehangoverisnotsomethingIwouldusuallycalldelicate,yettheReference150broughtoutthesubtlenuancesofeachandeveryinsultenduredbythoseravagedvocalcords,makingthereproductionfeelfarmorelifelikethanIhearfrommostamplifiers.Toputitanotherway,thisamplifierfilledinthespacearoundthenoteswithalltheextraneousinformationthatshouldbethere--thescrapingofachaironstageorapreviouslyunnoticedcoughintheaudience.Thiskindofdetailaddssubstanceandform,lifeandcontext,towhatisalltoooftenanalmostsynthetic,solelymusicalevent.Itputsthepeoplebackintorecordings.

LestallthistalkofbitsandscanlinessuggeststhattheReference150’sattributesshinemorebrightlyondigitalthananalog,fearnot.IpulledoutDiabolus in Musica, Accordo Interprets PaganinionDGG[DeutscheGrammophon02894776492],a1996LPcompilationontworecordsandasetthatequalsanythinginmycollectionformusicandsound.TheReference150

broughtouttheholographicsoundstageofthisrecordingbetterthanI’veeverheard.ThesoundoftheseLPsisexcellentonanydecentsystem,butasthequalityofthe

front-endandelectronicsincreases,therecordscontinuetoserveupanendlesssupplyofdelights.AfterswappingintheReference150forthe110,theLondonPhilharmoniccreatedadeeperandmorethree-dimensionalsoundstage,andthedynamicrangeincreased.Forthefirsttime,myattentionfocusedontheorchestralaccompanimentratherthanbeingcaptivated

byAccardo’spyrotechnics.

Thechangestotheamplifierwerealsofeltwithrecordsthathavesignificantbassenergy.TheReference150won’tmakethetwo7”woofersofanAvalonTranscendentsoundlikethe11”woofersoftheTime,norsupplythebasskickofmoreexpensivemonoblocks,butthedifferenceistheretohear.Evenwithspeakersthathavemoderatebassextension,theReference150’sextendedlowfrequenciesmakethemselvesknownwithgreatershapeandcontrol.OneofmyfavoritecutsforthispurposeisGol’s“AngelicainDelirium”

fromTrance Planet Volume Two[Triloka7210-2],long

outofprintbutadiscI’vebeenlisteningtosincethemid-1990s.ItproducesbasswellbelowthethresholdofanyspeakersI’vehadinmylisteningroom.Imadeadirectcomparisonbetweenthe110and150,andatfirstIthoughtIwashearinglessbassenergywiththe150,butafterhearingafewmorebass-richrecordings,Irealizedthatthe150simplytightenedupthebass,displayingmuchfaster,cleanerdecay.Iconfirmedthiswithsomeofmyfavoriteheadbangerrockmusic,includingWho’s Next[Track2408102]andLed Zeppelin II(UKPlumlabel[Atlantic588198]).Theserecordsareattheirbestonamuchlargersystem.Withmoremodestlysizedspeakersandastereoamplifier,it’seasyfortheloudestpassagestodistort.TheReference150heldthebassin

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laterincreasedto$10,995.TheReference150,pricedat$12,995,whileexpensive,canholditsownwithexoticamplifiers

costingalotmore.I’veusedorownedmanyAudioResearchampsoverthelast25years,

andIcan’trememberanimprovementbetweengenerationstocomparewiththeadvancesbuiltintotheReference150.Iapproachedtheamplifierwithmodestexpectations.Afterall,theReference110wasanextremelyaccomplishedperformer--myreference.Howmuchcoulditbeimprovedupon?Theansweris“alot.”I’venothadsomuchfunwithanewproductinalongtime.

checkinplaceswhereeventhe110wouldloseabitofcontrolandbecomemuddy.Andattheotherendofthespectrum,itaddedabitofextension.Theupperreachesofpianoandviolin,theshimmerofhigh-hatpercussionandthesparkleofpiccolo,allwelltreatedbytheReference110,confirmedthepublishedclaimthatthefrequencyextremesofthe150trumpthoseofthe110.

orme,theReference150isthesweetspotin theAudioResearchReferenceamplifierrange. TheReference110hadbeeninproductionsincemid-2006.Itstartedoffpricedat$9995andF

Price:$12,995.

Warranty: Threeyearspartsandlabor.

AudioResearchCorporation3900AnnapolisLaneNorthPlymouth,Minnesota55447(763)577-9700

www.audioresearch.com

Associated Equipment

Analog:VPITNT-6turntablewithrimdriveandSDSspeedcontroller,VPI12.7tonearm,LyraSkalaandTitanMonocartridges,KoetsuCoralcartridge,AudioResearchReferencePhono2phonostage.

Digital:AudioResearchReferenceCD7CDplayer.

Preamplifiers:AudioResearchReference5.

Power amplifiers:AudioResearchReference110.

Loudspeakers:AvalonAcousticsTranscendent.

Interconnects: NordostValhalla.

Speaker cables:NordostFrey.

Power conditioners:QuantumQBase8andQX4.

Power cords:NordostValhalla.

Equipment rack, platforms and accessories:BillyBagsequipmentrackmodifiedwitha4”mapleplatform,StillpointsUltraisolators,StillpointsComponentStands,FurutecGTXD-RhodiumACoutlet.