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SCD-1&SCD-777ESSuperAudioCD/CDPlayersTechnicalBackground1.
Introduction12.
Technology22.
1.
Overview22.
2.
FixedPickupMechanism32.
3.
DualDiscreteOpticalPickup42.
4.
ServoDSPLSI42.
5.
RFProcessorLSI42.
6.
DSDDecoder52.
7.
ACPSystem52.
8.
SynchronousTimeAccuracyController(S-TACT)72.
9.
CurrentPulseD/AConverter92.
10.
Low-PassFilter102.
11.
VC24DigitalFilter113.
Construction123.
1.
CircuitBoardLayout123.
2.
PowerSupplyBlock133.
3.
BasePillar(BP)Chassis133.
4.
InsulatorFeet143.
5.
Slide-TopLoadingPanel144.
Operation154.
1.
DiscTypeSelection154.
2.
DigitalOutput154.
3.
BalancedOutput154.
4.
Text154.
5.
Display154.
6.
RemoteControl155.
FeaturesandSpecifications165.
1.
SCD-1Features165.
2.
SCD-777ESFeatures175.
3.
Specifications17TableofContents1.
Introduction.
SuperAudioCompactDiscrepresentsaquan-tumleapinsoundquality.
ItsDirectStreamDigital(DSD)encodinggivesmusicafreshnessandpresenceunmatchedbyanyotheraudiotechnology.
Todemonstratethisnewformattothefullest,Sonyhasbuilttwolandmarkcompo-nents:theSCD-1andSCD-777ESSuperAudioCD/CDplayers.
Increatingtheseplayers,Sonydiscardedmanypreconceivednotionsaboutdigitalaudioanddigitalmusicreproduction.
Wehadtoinventnewapproaches,buildnewarchitecturesandpro-duceentirelynewLarge-ScaleIntegrated(LSI)circuits.
ItwastoexplaintheseaccomplishmentsthatSonycreatedthiswhitepaper.
12.
Technology.
2.
1.
Overview.
WhenCompactDiscplayerswerenew,audio-phileshadtolearnthenewlanguageoflaserpickups,digitalfilters,D/Aconvertersandanalogoutputfilters.
SACDhasacomparablelanguageallitsown.
ButSACDplayersarealsoCDplay-ers.
Sotherearetwosignalpathsinsidetheplayer.
Atsomestages,SACDandCDsignalsreceiveexactlythesametreatment.
Atothers,therearededicatedcircuitsstrictlyforonetypeofdiscortheother.
Here'sabriefoverviewofwhichstagedoeswhat.
21.
DualDiscreteOpticalpickup.
Incorporatestwoseparatepickups,oneoptimizedforSACD,theotherdedicatedtoCD.
2.
RFProcessor.
Forbothtypesofdisc,thiscircuitperformsclocksignalextrac-tion,synchronization,demodulationanderrorcorrection.
3.
DSDDecoder.
ForSACDonly.
AuthenticatestheSACDinvisiblewater-mark,separatestextfrommusicandformstheleftandrightDSDpulsetrains.
4.
ACPSystem.
ForSACDonly.
Controlstheinfluenceofswitchingdistortion.
5.
VC24DigitalFilter.
ForCDonly.
Asupremelyadvancedversionofthefamil-iar8xoversamplingdigitalfilter.
6.
S-TACTSystem.
ForSACDandCD.
Suppressestime-baseerrorsforjitter-freeperformance.
7.
CurrentPulseD/AConverter.
ForSACDandCD.
Supremelyaccuratecon-versionfrom1-bitdigitaltoanalog.
8.
LowPassFilter.
ForSACDandCD.
AGeneralImpedanceCircuit(GIC)stageforsuperbbandwidthandsoundquality.
9.
BufferAmplifier.
ForSACDandCD.
Discreteoutputcircuitryformaximumsignalintegrity.
TheSCD-1andSCD-777ESincorporatecircuitrytohandlebothCompactDiscandSuperAudioCompactDiscsignals.
SuperAudioCDPickupCDPickupRFAmplifierRFAmplifierRFProcessors16bit64s1bitACP&DigitalFilterS-TACTCurentPulseD/AConverterI/VConverterLow-PassFilterBufferAmplifier[s=44.
1kHz]DSDDecoderACPSystemDigitalFilterNoiseShaperPLMPulse&ReferenceClockGeneratorACP&DigitalFilterDISCFig.
1SignalFlowwithinSCD-12.
2.
FixedPickupMechanism.
Opticalplaybacksystemsrequiremotorservos,trackingservosandfocusservostomaintainaccurateplayback.
Unfortunately,thelaserout-putisextremelylowinlevel—makingitextremelysensitivetoradiatednoise.
Thatincludesnoiseinducedfromtheservocurrents!
Whileservocurrentsobviouslycan'tbeeliminated,theycanbeisolated,controlledandreducedbySony'sFixedPickupMechanism.
Itcreatesaquietenvironmentforclear,low-noisesignalreadout.
TypicallasertransportsmimicthedesignofLPturntables.
Thespindle,discandmotorarefixedinposition.
Thelaseractslikeaphonocartridge,trackingacrosstheradiusofthedisc.
TheFixedPickupMechanismchangeseverything.
Toiso-lateservovoltagesfromthelaserpickups,thepickupsthemselvesarefixed,rigidlyboltedontoasubchassis.
Whilethepickupsremainstation-ary,thediscandturntablemovehorizontallytoaccomplishtracking.
Asaresult,thesystemachievesextremelyprecisetracking—withextremelylowinducedservocurrentnoise.
Sony'sFixedPickupMechanismsuppressesservo-inducednoise.
ThisFixedPickupdesign—firstusedinSony'scritically-acclaimedCDP-XA7ESCompactDiscplayer—hasbeenfurtherrefinedbyhighlyadvancedsub-assemblies:Spindlemotor.
Madeofdie-castaluminumforhighrigidity.
Thestator(stationaryside)includesasapphirebearing.
Therotor(rotatingside)featuresarubyballthatfitsintothesapphirebearing.
Thiscombinationmakesforincrediblysmoothrotation—andreducedmotorservocurrent.
Italsoreduceswearatthecontactpoint.
Baseplate.
Thedrivemechanismismountedtoasolidaluminumplate,6mm(1/4inch)thick.
Thespindlecutoutisreinforcedwithanextraplateforaddedrigidity.
Specialopeningssuppressvibration,toreduceservocurrentsfurtherstill.
Floatingsuspension.
Theentiremechanicalblockfloatsonfourrubberdampers,mountedonfourchassispillars.
Thedesigncombineshighrigiditywithsuperbisolationfromchassis-bornevibration.
Discstabilizer.
Thediscisheldontothespin-dlebyamassivebrassstabilizerthattheuserplacesoverthecenterhub.
Thisdampensextraneousmotionandhelpscreateahigh-precisionrotatingsystem.
Thedie-castaluminumspindlemotorishighlyrigid.
Auniquerubyrotorballbearingminimizesfrictionandservocurrent.
32.
3.
DualDiscreteOpticalPickup.
CompactDiscrequiresalaserwavelengthof780nm.
SACDuses650nm.
CompactDiscrequiresanobjectivelensnumericalaperture(NA)of0.
45.
SACDrequires0.
60.
Insteadoftry-ingtocompromisetheserequirements,orswitchlensesorlasers,Sonyemploystwoseparateopticalpickups.
OneisdedicatedtoCDwhiletheotherisoptimizedforSACD.
Soyougetidealtrackingforbothtypesofdisc.
2.
4.
ServoDSPLSI.
SuperAudioCompactDischashalfthespacingbetweentracks(trackpitch)ofCD.
Thepitsthemselvesarealsohalfaslong.
Asaresult,SACDrequiresabsoluteprecisioninplayback.
That'swhytheSCD-1andSCD-777ESemployanexclusiveSonyDigitalSignalProcessor(DSP)tocontrolspindlemotor,trackingandfocusser-vos.
TheDSPmaintainssuperbprecisionforextremelystablesignalreadout.
2.
5.
RFProcessorLSI.
Astheopticalpickupreadsthediscsignals,anRFamplocatedinsidethemechanicalblockamplifiesthem.
ThisamplifiedRFsignalissenttotheRFprocessor,locatedonthemaincircuitboard.
TheRFprocessorchipisresponsibleforclocksignalextraction,synchronization,demodulationanderrorcorrection.
BoththeservoDSPandRFprocessorareSonyLarge-ScaleIntegrated(LSI)circuits.
LargeScaleIntegrationmakesforsmall-ercircuitboards—andreducedsignalexposuretohumandnoise.
42.
6.
DSDDecoder.
TheRFprocessorextractsthedatacontainedonthedisc,withoutinterpreting,analyzingorread-ingit.
OrganizingthedataintoleftandrightpulsestreamsisthejoboftheDSDdecoder.
AnotherSony-builtLSI,theDSDdecoderfirstreadstheinvisiblewatermark—akeyanti-piracyfeature—andthendecodestheincomingdata.
Dataonthediscoriginateasalternatingburstsofleft-channelandright-channelinformation.
Buffermemoryandmasterclocksyncenabletheburststobeoutputastwocontinuous,simulta-neousstreams.
TheDSDdecoderalsoreadssubcodedata,includingtextandTableofContentsinformationsuchastracknumberandplayingtime.
2.
7.
ACPSystem.
Inprinciple,itispossibletoconverttheDirectStreamDigitalsignalintoanalogwithnothingmorethanalow-passfilter.
Inpractice,theDSDsignalbenefitsfromsomehighlyspecializedpro-cessing.
TopreservethemaximumaccuracyoftheDSDpulses,ourdesignprogramidentifiedtwobasicgoals:*Amplitudeaxisprecision*TimeaxisprecisionSony'sAccurateComplementaryPulseDensityModulation(ACP)systemandCurrentPulseD/AConvertermeetthefirstgoal.
ThesecondgoalisachievedbySony'sSynchronousTimeAccuracyController(S-TACT).
5Theentireconversionsystemisoptimizedforprecisionontheamplitudeaxisandthetimeaxis.
DigitalFilterNoiseShaperCDdataSuperAudioCDdatas[s=44.
1kHz]64s64s8s64sACP&DigitalFilterS-TACTCurrentPulseD/AConverterEliminationofamplitudedistortionEliminationoftimeaxisinconsistenciesEliminationofamplitudeinfluenceACPSystemPLMPulseVoltagePulseCurrentPulseQuartzOccilationConversionV/IConversionI/VConversion&LowPassFilterFig.
3D/AConverterSystemThefirstelementinthisreproductionsystemisACP.
SonydesignedACPtoovercomeonepracticallimitationindecodingtheDirectStreamDigitalpulsetrain.
Intheidealworld,DSDpulseswouldbesquare,withcrisp,verticalleadingedges,flattops,flatbottomsandverticaltrailingedges.
SonyLSIsincludetheVC24DigitalFilter,S-TACTsystemandCurrentPulseD/AConverter.
Therealworldisadifferentplace.
Inreality,attheMegaHertzspeedsofDSDencoding,ICspermitsomeswitchingdistortion.
Leadingandtrailingedgesbecomeslightlyslanted.
Topsandbottomsbeginwithaswitchingglitch.
Thesedistortionswouldbeeasytocorrectinlaterprocessing—exceptforoneproblem.
Thedistortiononlyoccursatthetransitionsfrom1to0or0to1.
Whendigital1soccurinsuccession,thereisnoswitching—andnoswitchingdistor-tion.
Thesameistrueforastringofdigital0s.
Thisunevendistributionmakesswitchingdistortiondifficulttosuppress.
6100111/64sOnecycleACPsWithACP,theDSDsignalisconvertedintoacomplementarypulsewhichcontainsaleadingandtrailingedgeineachcycle[1/64s]sBecauseeachcyclecontainsthesamedistortioninboththeleadingandtrailingedges,thedistortioncanbeeasilyeliminatedbyshiftingthelevelsOnecycleDSDpulsesignalwithavalueof"1"sTheleadingedgeiswidersOnecycleDSDpulsesignalwithavalueof"0"sTheleadingedgeisnarrowerOnecycle1010OnecycleFig.
6IdealACPPulseSignalFig.
7DSDSignalwithACPProcessingSquareWaveformWaveformofICOutputOnecycleOnecycle10011OnecycleOnecycle64s10011SwitchingdistortionSwitchingdistortionNoswitchingdistortionsEachcyclecontainsavalue,includingplaceswherethevaluedoesnotswitchbetweencyclessSwitchingdistortionappearswhenthevalueswitchesfrom"1"to"0"andfrom"0"to"1"sThereisnoswitchingdistortionwhenthevaluedoesnotswitchbetweencyclesFig.
4IdealPulseSignalandDSDSignalFig.
5ActualICPulseOutputandDSDSignalSonysolvestheproblemwithAccurateComplementaryPulseDensityModulation.
ACPrepresentseachdigital1aswide1followedbyanarrow0.
ACPrepresentseachdigital0asanarrow1followedbyawide0.
Inthisway,everysampleincludesbotha1and0.
Soeverysam-plehasthesameminimalswitchingdistortion.
Asaresult,thedistortioniseasytoremoveinsubsequentprocessing.
TheACPsystemestablishesextraordinaryprecisionontheamplitudeaxis,acrucialfactorintheaudioperformanceoftheSCD-1andSCD-777ESplayers.
2.
8.
SynchronousTimeAccuracyController(S-TACT).
Fromtheearlydaysofdigitalaudio,itwasobvi-ousthatamplitudeerrorswouldequaldistor-tion.
Lessobvious,butequallytruewasthattime-baseerrorscouldalsodistorttheanalogwaveform.
Forthisreason,theSCD-1andSCD-777EShaveSony'smostcomprehensivedefenseagainsttime-baseerrors.
Alldigitalplaybackcircuitsincorporatequartzcrystaloscillatorstoregeneratepreciselytimedpulses.
Butnotallcircuitsachievethefullpreci-sionofthequartzcrystal.
Amajorcauseoftime-baseerrorisdigitalnoise,introducedthroughtheclockgenerator'spowersupply.
Forexample,thedigitalfilter,noiseshaperandACPsystemsallhavehigh-speedICcircuitry,handlingdigitalwordsupto50bitslong—atclockspeedsupto8timesthesamplingfrequencyofSuperAudioCompactDisc.
ConventionalcircuitsplacetheclockgeneratoronthesameICchipashigh-speeddigitalopera-tions.
Thearrangementisefficient,butitexpos-estheclockgeneratortohighlevelsofdigitalnoisethroughthepowersupplyvoltage.
Theresultisdistortionoftheclocksignal—jitter.
7Sony'sSynchronousTimeAccuracyController(S-TACT)resolvestheproblembyisolatingclockgenerationandvoltagepulsegenerationontheirownIC.
Removedfromhigh-speeddigitalopera-tions,theS-TACTcircuitdrawsclean,noise-freepower.
Thismeansthatdigitalpulsesapproachfullquartzaccuracy.
Jitter—andjitter-induceddistortion—aredramaticallyreduced.
8Conventionalcircuitsplacetheclockgeneratoronthesamechipashigh-speeddigitaloperations—exposingtheclockpulsestoharmfulnoise.
Sony'sS-TACTcircuitisolatestheclockgeneratorfromdigitalnoise.
DigitalOperationStageD/AConverterStageDigitalFilterACPSystemAudiosignalsData[64s]DataDataData512s256sBCK[64s]NoiseShaperBCKLRCKToexternalsystemToexternalsystemVoltagePulseGenerator&ClockGeneratorBecausethedigitaloperationstageiscompletelyseparatefromtheD/Aconverter,noiseisnotmixedinImprovedtimeaxisprecisionandimprovedsoundqualityDigitalnoiseiscarriedintotheD/AconverterstageDeteriorationoftimeaxisprecisionanddeteriorationofsoundqualityDigitalFilterCurrentPulseD/AConverter[V/IPulseConverter]I/VConversion&Low-PassFilterAudiosignalsCurrentPulseD/AConverter[V/IPulseConverter]I/VConversion&Low-PassFilterNoiseShaperPulseGeneratorClockGeneratorConventionalSystemFig.
8ComparisonofConventionalSystemandS-TACTDigitalOperationStageD/AConverterStageS-TACTDigitalnoiseinthepowersupply(Vdd)causesthetimebaseerrorscalledjitter.
TheS-TACTdesignsuppressesthenoise,tosuppressjitter.
2.
9.
CurrentPulseD/AConverter.
S-TACTeffectivelycleanstime-baseerrorsoutofthepulsetrain.
Thefinalstepbeforefilteringistocleanupamplitudeerrors.
TheACPcircuitdoesnoteliminateamplitudeerrors,itsimplydistributesthemevenlythrougheveryDSDsamplingperiod.
TheactualsuppressionofamplitudeerrorsishandledbytheCurrentPulseD/Aconverter.
Afamiliarfeatureofhigh-endSonyCDplayers,theCurrentPulseD/Achangestheincomingtrainofvoltagepulsestoatrainofcurrentpuls-es.
Becausethecircuitincorporatesanextremelyclean"constantcurrent"source,thepulsesemergewiththedesiredflattops,flatbottomsandidenticalheight.
Thehigh-speedswitchingdistortionsofearlierstagesarefinallycleanedoutofthesignal.
Theresultingwaveformisclosetoperfect.
Thepulsetimingapproachesfullquartzaccuracy,thankstoS-TACT.
Thepulseheightsareremark-ablyeven,thankstotheCurrentPulseD/A.
TheonlyremainingprocessinthedigitaldomainisasimpleCurrent-to-Voltageconversion(I/V).
Thankstoaconstantcurrentsource,Sony'sCurrentPulseD/AConverterensureshighprecisionontheamplitudeaxis.
FromS-TACTCurrentpulseD/AconverterVoltagepulse[DSD-ACPsignal]Currentpulse[DSD-ACPsignal]I/VConversionCleanandConstantCurrentPowerSupplyCurrentSwitchingCircuitFig.
10CurrentPulseD/AConverterJitterJitterVddOutputwaveformwithnojitterThresholdvoltageEnlargeddrawingVdd/2Vdd/2VddVdd[powersupplyfordigitaloperationstage]OutputOutputInputInputOutputInputNodigitalcomputationsmeansnodigitalnoiseDigitalnoiseisintroducedInfluencingtheVdd/2thresholdvoltagecausesthetimingtoshiftDigitalnoisevibratesVdd/2thresholdvoltageConventionalSystemS-TACTFig.
9ComparisonofJitterinConventionalSystemandS-TACT92.
10.
Low-PassFilter.
AfterI/Vconversion,asimplelow-passfilterisallthat'srequiredtoproduceananalogoutput.
Conventionallow-passfiltersusetransistors,opampsorotheractivecircuitelementsinthesig-nalpath.
BecauseSonywasintentonpreserv-ingthesimplestpossiblesignalpath,wechoseadifferentdesign.
OurGeneralImpedanceCircuit(GIC)low-passfilterpositionstheactivecircuitelementsoutsidethesignalpath,topreservetheintegrityoftheoriginalsound.
TheGIClow-passfiltertakestransistors,opampsandotheractivecircuitelementsoutofthesignalpath.
SuperAudioCompactDiscscanhavefrequencyresponseto100,000Hz.
Assuch,thecut-offfrequencyandcharacteristicsofthelow-passfilterhaveadirectimpactontheaudiospecifications—andsoundquality—oftheplayer.
Refiningthesoundmeansbalancingthevariousdesigngoals:flatamplituderesponse,maximumhigh-frequencyextension,lownoise,optimumphasecharacteristicsandsuitabilitywithdownstreamaudioequipment.
TheGICcircuitoftheSonySCD-1andSCD-777EStakeallthesefactorsintoaccount.
Frequencyresponseisflatto50,000Hz(sometwoandahalftimestheresponseofaCDplayer).
Above50,000Hz,responsebeginstorolloffslowly.
Theresultissmooth,open,non-fatiguingsoundwithexceptionaldefinitionanddynamics.
Sony'sfilterdesignachievesflatresponseto50,000Hz.
TheGICfilterisfollowedbyadiscretecomponentbufferamp,foroptimumcouplingtoapreamplifier.
AnalogcircuitwithGIClow-passfilter.
201001k10k100k-100-500Level[dB]Frequency[Hz]Fig.
12CharacteristicsofLow-PassFilterUsedinSCD-1StandardVCVSTypeActiveLow-PassFilterSignalspassthroughactiveelementsGICTypeLow-PassFilterSignalsdonotpassthroughanyactiveelementsSignalFlowSignalFlow+-+-+-+-Fig.
11GICTypeLow-PassFilter102.
11.
VC24DigitalFilter.
WehavejustdescribedtheSACDplaybackprocessfromlasertoanalogoutput.
However,theSCD-1andSCD-777ESarealsoCDplayers.
CompactDiscsgetthebenefitofmostofthetechnologieswehavementioned(servoDSP,RFprocessor,S-TACT,CurrentPulseD/AConverterandGIClow-passfilter).
However,exclusivetoCDplaybackisSony'sVC24DigitalFilter.
Thedesigngetsitsnamefrom24-bitprocessingandVariableCoefficientdesign.
Thefilter's24-bitprocessis2bitsmorepowerfulthanSony'spreviousbest.
Butthisactuallyunderstatesthecase.
Thenewfilteralsocon-ductstwiceasmanyoperationstepsandper-formsdirectoversamplingwiththreeadditionalbits.
Whenviewedintermsofoperationsteps,twobitsyields22or4timesasmanysteps,twicetheoperationsyields2timesthenumberofsteps,and3bitsyields23or8timesasmanysteps.
Alltold,theVC24filterhandles4x2x8=64timesasmanystepsasSony'spreviousbest.
SincethelaunchofCompactDisc,eachnewdigitalfilterhashadafixedfilteringcoefficient.
It'sbeendesignedatthefactoryandofferedtohomelistenerswithnousercontrols.
Sony'sVariableCoefficientdigitalfilterisadramaticdeparture.
TheVC24actuallyoffersfivedistinctsettings,representingdifferentfiltercoefficients,differentfilteringmethodsanddifferentobjectivesinreproducedsound.
Std.
Thestandardsettingmeetstheclassicdigitalfilterobjectivesofthesteepestpossiblerolloffabove20kHz,withthegreatestpossi-blesuppressionofultrasonicnoise.
df-1.
Thissettingincorporatessmoothinginter-polation.
Conventional8xoversamplingusesthreecascadedstagesof2xoversampling.
Incontrast,df-1performsthefull8xoversam-plingprocessinasinglepass.
Theresultissmootherprocessingandclearersound.
df-2.
Thissettingmaximizesthedigitalwordlength.
Ineachstage,itadjuststhewordlengthoftheinputnumbertomatchthenoiseshaperinthenextstage.
Thiseliminatesallnon-linearportionsinthecomputationprocessandsuppressesquantizationnoise.
df-3.
Thisisanall-new224-orderdesignwithanevennumberoffilters.
Unlikeconventional,odd-numberfilters,theoriginaldatasamplesareretainedas-is,withoutalterationbytheoversamplingprocess.
Frequencyresponseisflatto17kHz,whilenoisesuppressionat26kHzis80dB.
df-4.
Anenhancedversionofdf-2,thissettingincreasesthecomputationwordlengthbyfourbits,increasesthefilterdegreetwofoldandemploysaneven-numberfilter.
Frequencyresponseisflatto18kHz,withagainat20kHz.
11FiltertypeCut-offcharacteristicsPosition20kHz20kHz20kHz20kHz20kHzSTDstandarddf-1[No.
1Clear]SharprolloffSlowrolloffSlowrolloffSlowrolloffSlowrolloffdf-2[No.
2Plain]df-3[No.
3Fine]df-4[No.
4Silky]25622bit13bit[±2.
0]1125627bit[±2.
0]171+35+19131+2751224bit16bit[±2.
0]22411227bit[±2.
0]171+35+19171+35VC24PreviousVCMaximumnumberoforders[2-stagecascade4timesoversamplingfilter]Numberofoperationsteps[steps/44.
1kHz]OperationdatawordlengthCoefficientwordlength[Direct8timesoversamplingfilter]Maximumnumberoforders[Direct8timesoversamplingfilter]Maximumnumberoforders[Direct4timesoversamplingfilter]Coefficientwordlength[3-stagecascade8timesoversamplingfilter]Maximumnumberoforders[3-stagecascade8timesoversamplingfilter]CategoryTable1ComparisonoftheVC24andPreviousVCDigitalFiltersTable2Positionsfor24-bitVCDigitalFilter3.
Construction.
3.
1.
CircuitBoardLayout.
Afterpayingsuchmeticulousattentiontothecomposition,designandexecutionofeachcircuit,Sonywasequallycarefulinthephysicalarrangementofcircuitsinthechassis.
Themaincircuitboard—whichincludestheDSPservoLSI,RFprocessingLSIandsystemcontrol—ispositioneddirectlyunderneaththefixedpickupdriveassembly.
Thiswasadesignchal-lenge.
Forexample,itrequiredaholeinthecir-cuitboardtoaccommodateasupportpost.
Butthisconfigurationreducessignalrunsfromthelaserpickups,reducingexposuretopossibleinterference.
ThemaincircuitboarditselffollowsSony's"digitalminimum"design,withkeycomponentsascloselyconcentratedaspossible.
Toaccom-plishthegoal,Sonydesignedtheprintedcircuitpatternin4layers.
Andthenappliedsurface-mountLSIsandsmall-scalechipsonbothsidesoftheboard.
Asaresult,aphenomenalamountofcircuitryfitscomfortablyonasingle,smallboard.
Concentratingthemaincircuitboardandplacingitunderthemechanismleavesamplespaceinthechassisforthetwocircuitsthatneed"spreadingout.
"Thepowersupplyandtheaudiocircuitboard.
Sincetheaudiocircuitboardincludessomanycomponentsthatdeterminesoundquality,Sonypaidextraattentiontoitslayoutandconstruc-tion.
Thisisadouble-sidedglassepoxyboardwithabusbarandsymmetricalleft/rightlayout.
ThedigitalLSIs,includingVC24,S-TACTandCurrentPulseD/AConverter,areallsurface-mountcomponents.
Andthey'reallconcentratednearthefrontofthechassis,forminimumradia-tionofdigitalnoise.
Theanalogbufferampusesintegrated-leaddiscretecomponents.
Thesearewidelyspaced,forminimummutualinterference.
Voltagefortheanalogstageisprovidedbyadiscreteleftandrightpowersupplysecondaries,locateddirectlyontheaudiocircuitboard.
Separateleftandright3-layerbusbarshelpminimizepowersupplyimpedance.
Tooptimizegrounding,theaudiooutputterminalsarecon-nectedtotheaudiocircuitboardusingathickcopperplate.
SCD-1InternalstructureSCD-1Maincircuitboard(top)SCD-1Maincircuitboard(bottom)123.
2.
PowerSupplyBlock.
TheSCD-1andSCD-777ESpowersuppliesweredesignedtominimizeinterferenceandmax-imizethestabilityandpurityofvoltage.
Aremotepowerswitch,forexample,minimizesintertwin-ingoftheprimaryACwiring—restrictingittoashortrunatthebackoftheunit.
Separatepowertransformersforanaloganddigitalsectionslimitmutualinterferencethroughthesupply.
SonyusestwolargeR-Coretransformerstominimizemagneticfluxleakage,mechanicalvibrationandacousticnoise.
OntheSCD-1,vibrationisfurthersuppressedbyresin-sealedcasesforbothtransformers.
Theanalogaudiopowersupplysecondary(capacitorsanddiodes)ismountedontheaudiocircuitboardtominimizeimpedance.
Essentialparts,includingelectrolyticcapacitors,werecarefullyselectedforsoundquality.
Powersupplyblock3.
3.
BasePillar(BP)Construction.
GivenDirectStreamDigitalencoding'sabilitytoresolveeventhemostsubtlemusicalinforma-tion,theSCD-1andSCD-777ESweredesignedtorestricteventhemostsubtleformsofdistor-tion.
Microphonics—unwantedvoltagescausedbythephysicalvibrationofwiresandcomponentparts—havebeensuppressedbythoroughgoinganti-resonantconstruction.
Forthispurpose,Sonyhasdevelopedanewanti-vibrationdesign:theBasePillar(BP)chas-sis.
Thebaseconsistsoftwo5-mm(0.
2-inch)thickmetalplatesthatcombinetoformamas-sive10-mm(0.
4-inch)thickplatform.
Onthisbase,Sonyhasmountedsevenhigh-carboncastironpillars,two4.
5-mm(0.
2-inch)sidewallsanda5-mmtopplate.
It'snoexaggerationtocallthischassis"massive.
"TheSCD-1weighssome26.
5kg(over58lbs.
)whiletheSCD-777ESweighs25kg(55lbs.
).
BPChassisConstructionBychoosingintrinsicallyrigidmaterials,Sonyconstructedasimple,butverystablechassis.
Thechassisdesignisalsoextremelyopen,enablingtheideallayoutofeachsubassembly:mechanism,powersupply,mainboardandaudioboard.
133.
4.
InsulatorFeet.
Topreventshelf-bornevibrationfromenteringthechassis,Sony'seccentricinsulatorfeetlocatethescrewholeoffcenter.
Varyingtheradiusfromscrewtoperimetertendstovarytheresonantfrequencywithinthefoot—diffusingonepotentialpathforvibration.
TheSCD-1isdistinguishedbysophisticated5-pieceinsulatorfeet.
Theupperfootismadeofahigh-carboncastironthatoffershighattenuation.
Thelowerfootismadeofbrass.
Thesetwohalvesmeetatapinpointcontact,carefullydesignedtoblockthepropagationofvibration.
Finally,thepinpointitselfissurround-edbyagelshapeddampertoreduceeventraceresonances.
3.
5.
Slide-TopLoadingPanel.
Theloadingdooratthetopofthechassisisajewelofmechanicalengineering.
Itglidesonconcealedguiderails.
Thepanelrisesslightlyasitopens—andlowerstoitsoriginalheightwhenitcloses.
Themotorcoverandfloatingmechanismareinsulatedagainstnoiseandvibration.
Thedischousingistreatedwithananti-vibrationcoating.
Ahigh-carbontextilewithaTefloncoatingensuressoundinsulationandhighreliability.
Themainaxlefortheslidemechanismismadeofstainlessmaterial,whilethebearingismadeofsolidbrass.
144.
Operation.
4.
1.
DiscTypeSelection.
TheSCD-1andSCD-777ESautomaticallyrecognizeCDsandSACDsandcommenceplayback.
Byselectingthedisctypeinadvance,userscanbypasstherecognitionstepandgodirectlytoplayback.
ManualselectionisalsousefulforhybridSACDs,whichcontainbothhigh-densityandstandardCDlayers.
4.
2.
DigitalOutput.
TwotypesofdigitaloutputareavailableforCDplayback:coaxialandoptical.
Tominimizeradia-tioninterference,theseoutputscanbeswitchedoffbyafrontpanelcontrol.
ThereisnodigitaloutputduringSACDplayback.
4.
3.
BalancedOutput.
Toassurethehighestsignalintegrityatthepre-amplifierinput,theSCD-1featuresbalancedanalogoutputs.
Asfeaturedinprofessionalaudioequipment,thebalancedoutputsuse3-pinXLRconnectorswithseparateconductorsforplus,minusandground.
4.
4.
Text.
JustasCompactDiscoffersaCDTEXToption,SuperAudioCompactDischasareservedareafortext.
TheSCD-1andSCD-777EScandisplayinformationsuchasdisctitle,artistnameandtracktitleforcompatibleCDsandSACDs.
4.
5.
Display.
TheSCD-1andSCD-777EShavesegmenteddisplaysfortracknumberandtime.
BecauseSuperAudioCompactDisctitlescanhaveasmanyas255tracks,theplayerseachhaveathree-digittracknumberdisplay.
A15-characterdotmatrixdisplayshowstextinformation,playersettingsanduserwarningindications.
TheDisplayModeswitchenablesuserstoturnoffspecificsectionsortheentiredisplay.
Thedisplaywindowismadeofthickacrylicwithbevelededgesandahalf-mirrorcoatingontheinside.
Thishelpsgivetheplayersadistinctivelook.
4.
6.
RemoteControl.
EventheRemoteCommanderunitisdistinctive.
Itfeaturesa1-mmaluminumtopplateandbut-tonsthatdepresswithadefinitiveclick.
Theremoteduplicatesthefrontpanelfeaturesandaddstrackprogramming,shuffleandrepeat(1,all,A-B)aswellas10-keyDirectAccesstrackselection.
Additionalcontrolsincludecue/review,indexsearch,disctypeselectionandfilterswitching.
Theremoteunit'sinfraredcodescorrespondtoSonyCDplayercodes.
SomostSACDplayerfunctionscanbeoperatedfromtheCDplayermodeofSonypreamplifierandreceiverremotecontrols.
Topreventmistakenoperationinsys-temsthatalreadyincludeaSonyCDplayer,theSACDplayerandremotecanbeswitchedto"CD2"mode,engagingaseparatesetofremotecontrolcodes.
155.
FeaturesandSpecifications.
5.
1.
SCD-1Features.
PlaysSuperAudioCompactDiscsandCompactDiscsNewDirectStreamDigital(DSD)encodingeliminatesthedistortionsofdecimationandinterpolationfiltersDualDiscreteopticalblockwithonelaseroptimizedforSACD,anotherdedicatedtoCDTwinfixedpickuplasertrackingassemblyAccurateComplementaryPulseDensityModulation(ACP)systemforSACDplaybackS-TACTSynchronousTimeAccuracyControllerreducesclocknoise,minimizesjitter8-outputCurrentPulseD/AConverterGeneralImpedanceCircuit(GIC)analogfilter24-bitVariableCoefficientdigitalfilterforCDplaybackSuper-rigidBasePillar(BP)constructionAnti-resonant10-mmchassisbase,4.
5-mmsidewallsand5-mmtopplateDie-castaluminumspindlemotorwithsapphireandrubybearingsFloatingsuspensiontransportwithrubberdampersand6-mmbaseplate5-pieceinsulatorfeetwitheccentricscrewholes,high-carboncastironupperfootandbrasslowerfootMotorizedslide-toploadingBrassdiscweightAluminumfrontpanelBalancedandunbalancedanalogoutputsTwoencapsulatedR-corepowertransformersOpticalandcoaxialdigitaloutputsforCDTextdisplayforcompatibleCDsandSACDsRemoteCommanderwirelessremotecontrol165.
2.
SCD-777ESFeatures.
PlaysSuperAudioCompactDiscsandCompactDiscsNewDirectStreamDigital(DSD)encodingeliminatesthedistortionsofdecimationandinterpolationfiltersDualDiscreteopticalblockwithonelaseroptimizedforSACD,anotherdedicatedtoCDTwinfixedpickuplasertrackingassemblyAccurateComplementaryPulseDensityModulation(ACP)systemforSACDplaybackS-TACTSynchronousTimeAccuracyControllerreducesclocknoise,minimizesjitter8-outputCurrentPulseD/AConverterGeneralImpedanceCircuit(GIC)analogfilter24-bitVariableCoefficientdigitalfilterforCDplayback5.
3.
Specifications.
Super-rigidBasePillar(BP)constructionAnti-resonant10-mmchassisbase,4.
5-mmsidewallsand5-mmtopplateDie-castaluminumspindlemotorwithsapphireandrubybearingsFloatingsuspensiontransportwithrubberdampersand6-mmbaseplate4-pieceinsulatorfeetwitheccentricscrewholesMotorizedslide-toploadingBrassdiscweightAluminumfrontpanelTwoR-corepowertransformersOpticalandcoaxialdigitaloutputsforCDTextdisplayforcompatibleCDsandSACDsRemoteCommanderwirelessremotecontrol17SCD-1SCD-777ESSuperAudioCompactDiscFrequencyRange2-100,000Hz2-100,000HzFrequencyResponse2-50,000HZ(-3dB)2-50,000HZ(-3dB)DynamicRangeMorethan105dBMorethan105dB(20-20,000Hz)(20-20,000Hz)TotalHarmonicDistortionLessthan0.
0012%Lessthan0.
0012%Wow&FlutterBeneathmeasurablelevelBeneathmeasurablelevel(+/-0.
001%weightedpeak)(+/-0.
001%weightedpeak)CompactDiscFrequencyResponse2-20,000Hz2-20,000HzDynamicRangeMorethan100dBMorethan100dBTotalHarmonicDistortionLessthan0.
0017%Lessthan0.
0017%Wow&FlutterBeneathmeasurablelevelBeneathmeasurablelevel(+/-0.
001%weightedpeak)(+/-0.
001%weightedpeak)OutputDigitalOutputOptical,coaxial(CDonly)Optical,coaxial(CDonly)AnalogOutputUnbalanced,balancedUnbalanced(w/ON/OFFswitchforbalanced)OutputLevelDigital(optical)-18dBm(fixed)-18dBm(fixed)Digital(coaxial)0.
5Vp-p(fixed)0.
5Vp-p(fixed)Digital(unbalanced)2Vms(fixed)2Vms(fixed)Analog(balanced)2Vms(fixed)–GeneralDimensions(whd)430x149x436mm430x149x436mm(17x57/8x171/4)(17x57/8x171/4)WeightApprox26.
5kg(58lbs.
)Approx25kg(55lbs.
)1999SonyElectronicsInc.
Allrightsreserved.
Reproductioninwholeorinpartwithoutwrittenpermissionisprohibited.
Sony,CDTEXT,DSD,DirectAccess,DirectStreamDigital,DualDiscrete,RemoteCommander,SuperAudioCD,theDSDlogoandtheSuperAudioCDlogoaretrademarksofSony.
TeflonisatrademarkofDuPont.
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