A PR I L2O 1O. PLUS14pagesof music.VlNYL
RE-RELEASE
JeffBuckley's
Criie on18OgLP. AUDIOMITESTONES
Revox877openreeloINVESTIGATION
A briefhistoryof valves. ONLOCATION
loudspeakers.
- fromTrioto dCS
CabasseHl-Fl@HOiIEClassicalsystem

WWW.H IFIN EWS.C O.U K

U K € 4 . 0 0U S$ 9 .5 0Au s$ 9 .9 5

rirrfr, llJ|LrillflLlll!l(f,tz,ooo)
DevrdetD-Premier
Premierby name,premierby naturethisradical
newamplifier
from- untilvery
recently- anunknown,brandlookssetto challenge
theverybestaudiohasto offer
Review& Lab:PaulMiller
ncein a generation
a company beautifully
functional.
Aswe will discover,will emerge,oftenfrom leftthe D-Premier
operates
at veryhighfieldof audio'smainstream,
frequencies
and power- onlyby sealing
with a conceptso originalandtheseelectronics
in a gap-freeand nearinnovativethat it hasthe capacityto
enoughair-freealloyenclosure
canDevialet
guarantee
re-definethe exoectationsof a oroductthe freedomfromemissions
andgenre.Thatcompanyis Devialetof France interference
requiredfor CEcomplianceand its productisthe D-Premierintegrated andsalein the EU.
amplifier,expected
to costaround€ 12k
There'snot evena holeto
wh e nl aunc hed
in t he U K .
accommodate
an lReye,for the table-topEmbarking
on this review,little wasremoteisan RFdevice[seepicture,below
knownaboutthe nitty-grittyof theleftl,capableof adjusting
volume,input
D-Premierasidefrom its descriptionasanselection,bassroll-off(in 2.1 mode)andADH'(Analogue/Digitalphaseinversion
Hybrid)amplifier.
withoutline-of-sightof theIt wasnot exhibitedat CESin January
norD-Premier.
Spinthe weightedRFwheelandformallyannounced
to the press,so much
the Premier's
displayregisters
the volumeof what we'll discusshereis derivedfrom
from-97dBallthe way up to +30dB,theverycloseinspection
peripheral
andevencloserlab
clocKaceof dotsturningred
work,all exclusive
to Hi-FiNews.
oncethe amphasreachedits maximum
Thisisan amplifierofferingdirect
output.Thelatterisa lot easierto gauge
digitalinputsalongsideanalogueline
whenyouareemploying
a digitalfront-end
andMM/MCphonoinputs,an amplifierbecause
0.0dBon the displayrepresents
that fusesthe verybestof digitalandmaximumpower.Dependingon the signal
analogueengineering
to producea highly levelappliedto its analogueinputs,youyet supremely
configurable
elegant
couldreachthe endstopssubstantiallysolution.
ThetechnologyinsideDevialet's higheror loweron thisnumericalscale.
mirroredalloycaseworkis breathtaking
in
Buteventhe end stoosare 'buffered'its originality
andscope.lts constructionin thissophisticatedamplifier,for signals
is entirelymodularandcompletely
freeofabove0.0d8aresubjectto compression
wires,rightup to its4mm speakerbinding up to + 12dBanda formof soft-clipping
posts.lt mayjust be the finestamplifierwe thereafterup to +30d8.Withoutthis
haveeverheard.Or not heard.
intervention,
if the volumewereraised
above0.0d8andthe digitalmusiccontent
FRENCH CHEEK
containedpeakscloseto 0dBFs,
theAn unkindobserver
mightsuggestthat its
amplifiercouldsuffermomentarybutpolished
casework
bearsan unfortunate
crushinglevelsof distortion.
resemblance
to a setof bathroomscales,
but the single-piecealloychassis
is notTHEAT'DIOPHILE HT'B
simplyoozingFrenchchic,it is also
Leveringoff the rearpanel,an interference
fit at the top andbackof the chassis.
revealsa mixof connections.
Thesemaybe individuallyconfigured
toaccommodate
digital(coaxial
andopticalplusbalanced
S/PDIFAES/EBU),
analogue'line-level
andevenMM/MCphonosources.
Thereareevena pairof HDMIinput
RIGIIT:A backlittC displayindicatesboth
volumeandinputselection,
Thedisplaychanges
orientationdependingon wfiethertheampis
laidflat or placeduprightagainsta wall
22 j www.hifinews.co.uk
i nerul zotoand output connectionsto servicehighresolutiontwo-channelaudio from DVDI
and BD players.
Devialetwill supPlYa PC/Mac
applicationthat allowsfull customisationfrom naming airdof the D-Premier,configuringthe sockets(input,output,
digital or analogue)and even specifying
the output power from 160W to 240W.
The default is 165W/8ohm.You customiseand storethe configurationonto an SD
card and simplyplug it into the readeron
the rear of the amp.
Thereare plenty of other elegant
touches to hand - the display rotatesaccordingto the physicaldispositionof
the amp, for example,while high volume
settingsare automaticallyreducedif nodigital input is sensedfor a period. Leave
the amp for half an hour or so and it drops
into a 5W standbymode. Warm-uptime?
Well, that's the time taken for its OStoboot - about ten secondsby my reckoning.
Our sampleoperated in default mode
only and while the HDMIfacilitywas notboard
enabled,the HDMI receiver/repeater
was fitted in place [see picture, P24]. N
the time of writing, Devialetstill hasto add
the handshakingthat ensuresthe HDMI
source(Blu-rayor DVD player)sendstwochannelPCMand not multichannel,Dolby
or DTSencoded bitstreams...
A singleset of 4mm sPeakeroutlets
are fitted but if you are to benefit fromthis amplifier'sfabulouslylow output
impedancethen kindlydiscardany notionsof usingscrawnycables,regardlessof
audiophilepretention.With this proviso
in mind, if hooking-upthe D-Premieris adoddle then keepingit free of fingerprints
is an exercisein severeself restraint.
Visitors,whether audiophileor not, will
be compelledto touch that beautifully
mirrored surface,so keep Devialet'smonogramedcleaningcloth to hand!

PRFUENIION, NOT CITRE
A glanceat our technology boxoutson
this and p25 suggestsa deal of custom
operation.
DSPoverseeingthe D-Premier's
But these powerful Analogixprocessorsdo

thenot onlycalculate
PWMsignalrequiredto drivethe ClassD
theycurrentdumpers,
alsoorovidea measure
forof compensationin bothnon-linearities

Moreover, my exPerimentsshowed
Devialethas programmedthe DSPwith
a very sophisticatedprotection regime.
Ratherthan wait for an over-voltage/current or temperaturecondition to arisein the ClassD stage (althoughsuch afailsafeis also implemented),the digitalaudio is continuouslymonitoredfor
patterns of level and/or frequency thatwould over-modulatethe PWMstage.Thus
the protection is in part predicflve - theD-Premiersimplynever allowsany data
into the ClassD amp
that would causeit
to fail. And believeme, when a beefy
ClassD amplifiereven
momentarilyexceeds
its safeoperating'Warm-uptime?
Abouttenseconds
by my reckoning'

ClassD and, particularly,ClassA stages.
Calibratedfor frequency,digital volume
positionand output levelthe heightened
orecisionof the DACand ClassA l-to-V
stagesare what shapethe performanceof
the D-Premieras a whole. lf we were able
to measureor listento the ClassD stage inisolation,we'd discoverit was far'rougher'soundingthan the combined efforts of its
ADH output [seeboxout, below].

ADH- Analogue/DigitalHybrid - amplifiertechnologyis an entirely proprietary
regimethat combinesthe servicesof a very low power analogueClassA
amplifierwith a very high power,truly digital ClassD amplifier-Here'show itworks:the analogueClassA amplifier is directly coupledto the sPeakeranddefinesthe full voltage swing availablewhile the digital classD amplifier
provides99%of the current 19quiredto maintainthis vohage acrossthe speakerload.The idea is not dissimilarto Quad's 'feedforward'ClassA/B Current
Dumpingtechnique applied in its 405 power amplifier some 35 yearsearlier
lWiretessWorid, Dec 19ZSl.In both casesthe ClassA control amplifier (a highvoltage preamp)utilisesan error signalderivedfrom the current dumpersto*'lloo":':t;i1l'i::'J"'ilgffll'i"i;

ABOVE: The 6.9k9 DPremier is fashionedfrom
a singlealloycasting- 32mm thick gently
radiused,chromed and polishedto a perfectmirrorfinish.White glovesare supplied!

canseeit
oscillation
areaa parasitic
in an instant.
destroyedlIl souNDoF SILENCE

How to describethe Performanceof
this amplifier?lmagineyou are sitting
in a concert hall.The orchestrafinishes
its warm-up and the sound of individual
stringsand winds drift away i6 tne vaultsof
the venue.The audience'scoughs,spluttersand rustlingof programme notes diminish
to a respectfulhush.The lights dim and you
closeyour eyes.Silence.
For a long moment the audienceholds
its collectivebreath for there is no lead-ingroove,no tape noiseor hissof electronics
to announcethe first notes of this overture.
Then it comes.The strikingcrashof cymbal
and deep resonantwave of the tympani
strike your body. Eyesnow wide open,
heart roused from its lazy rhythm you
know you are witnessinga visceral,liveperformance.No hi-fi comes close,youthink, no hi-fican realisethis spontaneous
dynamicrange,this vivid colour andof real instrumentsthrobbing
exDression
beforeyour eyesand ears.
GenerallyspeakingI would agree,
but the sound of the D-Premierfed from24-bit StudioMasterquality digital files
comes astonishinglyclose.In fact, theonly time I experiencedthe uncanny
perceptionof music risingfrom a similarlyo

it'stheperrormance
totheDeviaret,
ristenof this very linear classA control amp that definesboth the numbeis and itssound.Moreoverin this Frenchexampleof the art, the ClassA amp alsofilters
the triangular ripple current from its noisydigital ClassD switching stage.In one
step the needfor an invasivetC fiher - usedbetween the modulator and speaker
outputs of all other classD amps- is avoided.uniquely for a classD design,theD Premieris fundamentallyinsensitiveto variationsin load between one speaker
and the next, opening up a huge choiceof partnering boxei for the audiophile.

APR|L2olo www.hifinews.co.uk
I 23

',,,

ABOVE:Devialet'scustomfour-phase
ClassD
amplifiermoduleunhooked
frominsidethe
IlPremier.Topleft (mainpicture)shovvsthe
exposedqvitchmodePSUminusits screening
can;bottomriglrt revealsthe HDMIinput
blackbackgroundwasduringmytime
with a prototypetrue digitalClassD
amplifierin 1995,the forerunnerof theTacTMillennium.
At the time I likened
the experience
to 'steppingout into aclearroadonlyto be knockedoverby anelectriccarturningthe corner'.Butthis
wasoperatingat just 16-bitsandthe hugeswellof ultrasonicrequantisationnoisejustoutsideof the audioband
hadvet to be
dealtwith.

andclarityof a soloist.Thewistfulcolourof cor anglaisseparated
fromthe reedieroboe,the celloplayfullymockingthe
The innovativebrainsbehind thegranderdoublebasses
whilehorn,trumpet
DPremier was insufficientlytaxed atandtrombonesoared- metallicbut richly
the R&Ddept. of Nortel Networks.
coloured,nevertoo coolor dispassionately 'l started day-dreamingaboutbrassy.
Andthe whole?Thiswassimply
designingthe best amplifier ever,superb,so roundedand harmoniouslywith the highestefficiencyever,'heyoufelt compelledbalanced
to reachoutsays,'and the idea of associating
andembracetheirranks.
ClassD and A amplifierscalqq
I alsohadoccasion
to enjoya
swiftly.' The underlyingtechnology
two-channel
renderingof EricClapton,
was patented in 2004 and Devaliet
THE NEKI GENERAIION
RogerTayloret al in A Concertby theSASin Pariswas on its way, PierreYearslaterandDevaliet's
D-Premier
evokes Lake[ERBRD5049
Blu-ray],
the Devaliet
assistedby another ex-Nortel
verysimilaremotions.
Thistime,however, capturingthe openatmosphereof thiscolleagueMathiasMoronvalle.
the background
isn'tjust black,it'sa chasm veryselecteventwith its customary
Fundingand encouragementof calm, a cool silencethat
transparency.
Thefrom an industrialdesigner(andstretchesback beyondthecrispnightair wasaudiophile)brought the D-Premier
obvious reachesof thepalpableasClapton
prototype to productionfrom 2007
stereosoundstage.
to 2010.'lt hasbeena realteam
Thisabyssalcanvas
effort' revealsPierre,'involvinga lot
explainswhy I sat transfixedof core competencies'.
by an NHKpresentationa gentlemanlyof the Saito KinenFestival
performance,theon Blu-rayIBerlioz's
fellasclearlylacking
Symphonie fantastique, NSBS134571.Only the gustoof theiryouth.Well,I neversaid
now wasthe 24-bitdynamicrangeof thisthe Devialet
wassympathetic.
digitalrecording
finallybeingrealised,In general,the verybestampsareable
injecteddirectlyfromthe S/PDIF
outputof
to makeyourspeakers
meltfromthe room,a MarantzUD90O4universal
player[HFN,projectinga musicalperformance
intotheDe c'0 9 ].Theonlyanalog useta g ei n th espacebetweenandaroundthem andyou.
signalpatha low power,ClassA voltage
There'sno obvioussenseof boxesin theampguidingthe outputof the D-Premier... roomasthe musichangs,palpablebut
Everyperformerin thissubstantial
independent.
Theinsightthisprovides
intoorchestrawas revealedwith the orecision
the musicisfantastic- whenit happens.

'}bu knowwhen
you' arewitnessing ::11'l"j':"alive,viscei;T--:filX',i",il:JJ:'lp€rformance'

24 i wr,vw.hifinews.co.uk
5nprul zotO

representthe performanceof
Thefollowingmeasurementss digitalcore and the graphsmay be compared
the D-Premieir
playerordirectlywith thoseobtainedfrom anyCD/DVD/BD
outboardDACreviewedin HFIVin the lastthree years.Only
here the output at 0dBFs(peakdigital)is not the customary2V
but a full 36.3VdeveloPing165{8ohm' Whileperformance
via the analogueinputsis limitedby a mere48kHzsampling'
the digitalinputsoffera futl 0.1Hz-gokHzoutput bandwidth
the distortionversus
with up to 24-bit/192kHzdata.Crucially,
diqitallevel(lessthan 0.005%overthe top 50dB of its dynamic
is superiorto any outboardDACmeasured:9lul.*.hil"ra-nge)with 48/96kHz
Aigitailiuer is an almostinvisible40/5Opsec
da-taat l OWSohm- a fabulousresultaidedby all clocksbeingtransmittedin differentialmode acrossthe amp. Equallysuperb
is the 12odBA-wtdfull scales/Nratiovia the digitalinputs(thisis closerto gOdBre. 1W8ohm viathe analogueinputs)'
the programmeof the speaker,
Dependingon the sensitivity
contentand preferredlisteninglevel,the positionof thevolumecontrolmaywell be shiftedoff the 0'0dB
D-Premier's
spot,promptinga changein (digital)distortions,particu.larly
Unitygainoccursat volumeposition
at higherfrequencies.
input, 1{8ohm is achieved-22.5d8 while,with a OdBFs
at -22.0d8. Distortionfallsto just 0.00025%at 1kHzin thisposition,increasing
to 0.0i 2%at 40kHzwith 96kHz/24-bit
QC Suiteare invitedto view a comprehensive
data.Readers
digitalinput,DSPand DAC
test reportfor the D-Premier's
and clicking
p"rtortun." by navigatingto wvvw.nifinews.co.uk
PMon the red'dow nl oad'button.

4:.

bc

AgoltE: seen from above,or mounted vertically on a wall, Devialet's port hole not
only revealsits ADHtechnology motif but also housesa hidden wi-Fi antenna. A riser
for an ocension board is alreadyin placeto accommodatestreamingof hi-resaudio

doessomething
Butthe D-Premierquitewonderful'else,somethingtoI returnedto that tYmPani,
the shocking
experience
Pulse
energyonceagainof musicalthat whilethe bodYand realised
wasPerfectlyof the instrument

the imageof the bowl
proportioned,andtaut skinwasnot justsimPly
projectedintothe room.Insteadit
itselfwas
seemedasif the sPeakerasif the verywallsof
the instrument,B&W802swerethe
my substantial
kettleof the drum.
ThecontrolexercisedbY

All inputs to the D-Premierend up in
the digital domain,analogueinPuts
via a 48kHzsamplingADCand digital
inputs via 192kHzuPsamPling.This
24-bit/ 192kHzaudiodata is used
to derivethe -300kHz PWM (PulseWidth Modulated)signalfor theClassD amp.Thisdescribesthe signal
amplitudeby the relative'width'ofpulsesin the chain,the underlyingaudio signalbeing recoveredbY
filteringthroughthe highlylinear
ClassA amP[seeADHboxout, P23].
The €lassA amP,meanwhile,is also driven by this digital data
after volume and other correction
is applied.DevialetusesPairsof
Burr-BrownPCM1792DACsin a
proprietary'current reflector'
bothconfigurationthat encompasses
l-to-Vconversionand gain for thebias-correctedClassA outPut stage.

this amplifierover any of thespeakersI tried, including
modelsas diverseas Sonus
f aber M inim a ,M a g i c oM 5 0and B&W 802 floorstanders,is seeminglytotal. After all, it
has a vanishinglylow outPut
impedance,a resPonseflatt o wit hin 0 . 1H z o f D C a n da power supplycapableof
doubling its output witheach halvingof sPeakerload impedance.The mostrecalcitrantof sPeakersare
renderedutterlYcomPliant.

DO PASSJAII,of thelf the performance
inPutsanalogue
D-Premieis
are ratherat the mercyof
outPut)bothinput(source
levelandthe ADC'sineffectual
filter[seeLabanti-aliasing
Report,p27]then itsvarious
digitalinputsarecertainlynot.O

47t{Dstccing}

Digftal slgml Ldol >>@I

ABOVE:Distortion vs. digital signal level from odB(165W)to -120d8 (0.17nW)with 24'bit data at'0.0d8'vol. position(l kHz = black;20kHz= blue)^v

ABOVE:High resolutioniitter plot showing 48kHzl24'bit (black)and 96kHz/24-bitdata (red)measuredat
towlaotrm output. litter is exceptionilly low

Distortion {1kHz,0dBFs/-30dBF+(16sw) / 0.o0056%(0.17W)
0.0014%

Distortion & Noise{10kHz.0dBFs)
Frequency resp. (192kHzl24'bit]t+0.0dB(lOHzito -8.7d8(90kHz)

24'bit)Digitaljitter (48kHz/96kHz.

i 25
APRIL2OlOj www.hifinews.co.uk

fitifff***,,''u53OYG; Devialethasequippedits amp with an HDMIv1.3 input and output' twodigitalTosfink optical digital inputs (up to2+bitl192w1z) and a balancedAES/EBU(uPto
inputs/outPuts
digitalcoaxialinput,twophonoandline
MM/MC
input.The
24-bitl192kHzl may be conf igured to use arryof the sk visible RC'Asockets'
atmosphere,detail,the harmonious
I am inclinedto treattheFranklyintegrationof the Performersand,inputsasa 'get out of jail'analogueabove all, the palPablerealism ofgear
includingfeaturefor legacy
or pre- the piece was caPtivating.
tuners,reel-to-reelanalogue
Otherwise
digitalout CDhardware.
DIGITAI, STRE,AIVIING
goingto usethe
you'renecessarily
digitaloutputof yourdiscplayer'But I cherishedthe time spent listening
to the highestresolution(Studiothethat'sjustthe start.In practice,Masterquality)digital files storedon
is mannafrom heavenfor
D-Premiera 4TB QNAPNASserver,navigatedtemptedalreadythoseenthusiasts
by PCand renderedvia the digitalor Blu-raY
by musicon DVD/DVD-A
music output of a Linn DS PlaYer.As
or, indeed,the highresolution
CD beginsto lose its lustrefor
offeredbYLinn,Naim'downloads
committed two-channelaudiophiles,
boY,
doesAnd
Cheskyand others.
the step-upfrom 16-bitCDto 24-bit there'san inclinationto gravitate
towards the luxuriantsound of topDVD-A,BD,FLACor WAVformatsat
notch vinyl and/orthe sensational
difference!
amake192kHz
48kHztoffi#Iil#fluJfri":gi[,p**t***"mr*lif,i.';*::ln:n*',:1i:'l#T:i'#i;3',1iiilf
e'.['I,5:;HHH?JhlElXi**ru***N*t*ui$**'i;n**l#resolution afforded bY 24'bit DRMfree audio downloads.
RESOLTIIION HVOLIITION
CertainlyI've never heard aThere'sa nifty DVD-Afrom TheProject,a collaboration plain vanillaCD plaYeroffer theResolution
DolbY'Derformanceof a Linn DSdelivering
betweenDPAmicrophones,
24-bitlg6k{z digital audio throughsoftwareandothers,
Minnetonka
The soundthe DevialetD-Premier.
of thea liverecordingthat includes
caressingvoice
Martin's
Claireofinasmall
Trio
MaryLouiseKnutson
the gentle tune that is 'Shadowville'
churchpresentedin a varietYofformatsincluding16-bitl44.1kHz[PerfectAlibi, 24-bitl96kHz FLAC]
soundedtruly alluring,her presence(CDquality)up to the holYgrailof
as solid,the intonation as velvety- the nativeinternal
24-bitl192kHz
and emotive as if she reallYwere
TheCDof the D-Premier.
resolution
the standingin front of those B&Ws.For
fabulous'
stillsounded
resolution
those so inclined,this is the future ofof Percussion
delicatebrushwork
exquisitemusic making in the home'theoveraction
andMary'sdexterous
all liftedby the dark,dark short of hiring Ms Martin to performkeyboards
affordedby thisamplifier, for an evening.{Dbackdrop
or digital
freeof anyhintof hardness
hash.lt soundedasPureascool,water.
crystal-clear
lf I could award Devialettwo
Switchto the 24'bitl192kHz
badgesthen I would,because
formatandthisdarkfloorjustfalls
the D-Premieris both this Editor's
theaway,revealing
completely
choiceand fhe outstanding
intakeof breathfromthe
collective
amplifierthusfar of the new
the instantbeforeMary
audienceof
Thetaut Precision
Millennium.
beginshercountdownand PhilHey's its performance
will not suPPlant
the trio.The
bassdrumannounces
the gloriouslyrichsoundsought
depthof boththe drum
resonant
andby tube-lovingaudioPhiles,
andacousticbassjust keePsonthat'sjust fine.Butfor enthusiasts
going,drawingout low frequencies runningveryhigh resolution
I didn'tknowexistedfromthe
the D Premier
digitalfront-ends,B&W802s,asthe
substantial
binarychoice.
is Hobson's
percussive
impactof ivorymingles
90%
0uatity:Soundwith the chinkof icein a glass,reflectedoff the brickwallsof thislivelybut intimatechurchvenue.The

ABOVE:Dynamicpower output versusdistortion into(b'ue)
and2ohm
i:lil lili:ilft?f:lH.t"'''Distortionrr"ffi"t row/sohmfitack
ABovE:"r.
= left, red = right channel)
showing exceptionallyconsistentperformanceacrossthe audio rangePffi€r output (<1%THD,&i 4ohm)
Dynamic pMr(<1%IHD,8i4l2/lohm)

r65w /330w /6sow /32s w-O.OdBto-2.9d8 (seerabP25)
lnput snsitivity (forOdBW/165WI
A-wtd SIN mtio (re.0dBW/165WI

91.3d8/ l - t3.7dB

ffii,fffi,ffiffiffiffiffiffiilhffi*o2o1o i www.hifinews.co.uk
APRIL! zz