SPECIL ISSUE 61 UDIOPHILE-QULITY RECORDINGS RECOMMENDED ONLINE UTHORITY: WWW.STEREOPHILE.COM STTE-OF-THE-RT DIGITL PERFORMNCE ML S NOLE N31 REG RESERCH S RP10 TURNTLE P.19 FERURY 2018 IN REVIEW POWERFUL MPLIFIERS FROM JDIS, PSS LS, PS UDIO MZING LP PLYERS FROM MOFI & REG VM S OVTION MP 8.2 CD/MEDI PLYER TD S MICRO EVOLUTION ONE MINIMONITOR TECHNICL INVESTIGTION MQ S UDIO ORIGMI
EQUIPMENT REPORT JOHN TKINSON ML Noble Line N31 CD PLYER D/ PROCESSOR ML s Coona C15 monoblock has been one of my amplification efeences since I eviewe it in 2014, an as I ve been eviewing DCs the past yea o so, it was high time I spent time with one of the Geman company s igital poucts. lack shiny poucts ae tough to photogaph at shows, so tust me when I say the new N31 is ipping with gogeousness not eflecte in this photo, wote Jon Iveson in his epot fom the 2017 Consume Electonics Show. n when I unpacke my eview sample of the Noble Line N31 ($15,400), I was inee taken with its looks. The N31 s font panel is ominate by a lage, 5", colo TFT isplay, flanke on each sie by thee function buttons that ML calls soft keys, an below it the slot fo the vibationampe CD tanspot. (The N31 ecognizes CD text an isplays the title infomation.) On the top panel is a cicula, inente touchpa that contols the bightness of the isplay in six steps an glows a soft white. The N31 s ea featues ES/EU, optical an electical S/ PDIF, an US 1 an US 2 igital inputs; ES/EU, an optical an electical S/PDIF igital outputs; an balance an unbalance analog outputs. Thee is also a slot fo an SDca, fo fimwae upates. The igital inputs an outputs ae all galvanically isolate, an oscillatos not equie fo a selecte input ae automatically shut own. I inteviewe ML s chief esigne, Jügen Reis, at CES 2017. 1 When I aske him what was special about the N31, he tol me that they concentate on minimizing jitte. The US inputs ae powee fom a sepaate tansfome wining, an ae optically isolate fom the igital cicuity an the analog auio cicuity. Thee is a thee-stage jitte-euction stage: fist, a igital PLL with a wie, 10kHz acceptance winow to allow the N31 to lock to a souce; then an analog smoothing PLL with a 1Hz cone fequency to eject highe-fequency jitte; an, finally, an asynchonous eaout buffe. The output of this last stage fees the N31 s ovesampling filte, which eals gacefully with intesample oves. Intesample oves occu when the igital ata have consecutive samples at 0FS. When the igital econstuction filte intepo- lates the analog wavefom, the esult is a wavefom that coul peak up to 3 above 0FS. If the DSP enginee esponsible fo the igital filte has not allowe any mathematical heaoom, the wavefom will be clippe. Steeophile use to outinely examine igitalfilte heaoom, as you can see in ou eviews oiginally publishe in the ealy 1990s. ut that was befoe the Louness Was, when CDs wee mastee so that thee wee neve consecutive samples at 0FS. (Some igital-auio wokstations calculate the wavefom on the assumption that it woul be pocesse by a typical igital filte, thus allowing the masteing enginee to avoi intesample oves.) Such oves ae ae to nonexistent in classical ecoings, I ve foun, but both Reis an enchmak s John Siau 2 have analyze a lot of ock ecoings an foun many pathological examples. Fo example, in Gaslighting bbie, fom Steely Dan s Two gainst Natue, Siau foun 1129 intesample oves: 3.7 pe secon (see Measuements sieba). Reis explaine that the N31 s igital filte has 3.5 of heaoom, so that when thee ae intesample oves, the DSP will neve clip. s supplie, the DC chip use in the N31, a balance ESS Sabe 9018, oesn t have intesample oveloa potection an offes geneic filtes. Howeve, the basic specifications ae vey goo, an the chip s topology allows Reis to manipulate its behavio to eliminate the things he oesn t like about it. Fo example, while ESS s on-chip filte has 128 taps, Reis moifie it to have just 32 taps, to obtain a subjectively esiable shot filte. ML also uses its own technology to iffeently weight the fou DC paths pe channel, to smooth the tansition between the elta-sigma an multi-bit sections that occus, I unestan, at aoun 36FS. The DC is followe by an analog low-pass filte an a one-stage output buffe, esulting in a vey wie ynamic ange (see Measuements sieba). Setup The N31 s emote hanset offes CD playback contols, as well as 1 See https://tinyul.com/y9xk9tn. Michael Lavogna an I also talke to Jügen Reis about moe geneal aspects of igital auio; see www.youtube.com/ watch?v=smmdlfp4so. 2 See https://tinyul.com/ybzau5vu. SPECIFICTIONS Desciption CD playe an D/ pocesso with emote contol. Digital inputs: 1 ES/EU (XLR), 1 coaxial S/PDIF (RC), 1 TosLink, 1 US Class 1 (Type ), 1 US Class 2 (Type ), 1 SDca slot fo fimwae upates, 1 ML SmatLink (RJ45). Digital outputs: 1 TosLink, 1 coaxial S/PDIF (RC), 1 ES/ EU (XLR), 1 ML SmatLink (RJ45). nalog outputs: 1 pai balance (XLR), 1 pai unbalance (RC). Digital fomats suppote: 16 24 bit/44.1 192kHz PCM; DSD64 (DoP). Fequency esponse: not specifie. Maximum output level: 4V RMS balance, 2V unbalance. Output impeance: 200 ohms balance, 100 ohms unbalance. THD+N: <0.001%. Signal/ noise: >120. Powe consumption: <20V in opeating moe, 0.5V in Stanby. Dimensions 17.7" (450mm) W by 5.9" (150mm) H by 16.3" (415mm) D. Weight: 39.7 lbs (18kg) net, 48.5 lbs (22kg) shipping. Finishes White/Chome, lack/chome White/Gol an lack/gol. Seial numbe of unit eviewe 0034. Pice $15,400. ppoximate numbe of eales: 10. Manufactue ML kustikgeäte GmbH & Co., KG, Kufüstenamm 182, elin 10707, Gemany. Tel: (49) 030-2300584-0. Fax: (49) 030-230058410. Web: www.mbl.e. US istibuto: ML Noth meica, Inc., 217 N. Seacest ouleva #276, oynton each, FL 33425. Tel: (561) 735-9300. Web: www.mbl-nothameica.com. ERIC SWNSON 2 Febuay 2018 n steeophile.com
The N31 s US 2 input will wok with idevices unning ios7 an up, using pple s Camea Connection Kit. steeophile.com n Febuay 2018 3
ML NOLE LINE N31 the basic functions fo ML s N51 integate amplifie. It s a substantial, cicula beast, finishe in black with chome tim, an seems to have some egee of selfawaeness when you each fo the emote, even befoe you ve touche it, its buttons labels light up. The N31, too, senses the use s appoach, the Menu an Device (input) icons on its isplay appeaing befoe any of the buttons to left o ight ae touche. s I m use to touchsceens, it took me a while to lean not to push the onsceen icons an instea pess the associate buttons next to them. s the N31 has no volume contol, I pefome my initial auitioning using an ye coustics KX-5 Twenty peamplifie. ut afte I shippe the ye to t Duley, fo him to eview fo the Mach issue, I use a balance NHT Passive Volume Contol I bought a few yeas ago, using shot, balance Canae cables, with a 1 4 " TRS jack on the sening en an a male XLR on the othe, to connect the NHT PVC to the amplifies. Soun It s common to escibe a pouct s geate esolution of ecoe etail as always being an impovement. Howeve, it s also common fo this geate etail to be accompanie by too up-font a soun uthlessly evealing, as the auiophile cliché has it. The ML Noble Line N31 avoie this synome, opening a clean winow on the ecoing s sounstage but without thusting things fowa at me. I chose fo one of my Recos to Die Fo in this issue Robet Silveman s pefomances of the two Rachmaninoff Piano Sonatas fom 1980 an 1991, which we eissue in 2007 (CD, Steeophile STPH019-2). I han t playe this isc fo some yeas, but packing fo an office move last Novembe, I foun a CD-R I bune fom the DDP file set I pepae fo the pessing plant. Playing it in the N31 emine me why I han t wante these ecoings to isappea. Silveman s Hambug Steinway in Sonata 1 was hanging thee between an behin the GolenEa Technology Titon Refeence speakes, palpably pesent (as that othe auiophile cliché puts it). Yes, I coul hea an occasional touch of flutte, but I coul ignoe this in favo of the shee tangibility of the N31 s pesentation of the MESUREMENTS I measue the ML N31 with my uio Pecision SYS2722 system (see the Januay 2008 s We See It, http:// tinyul.com/4ffpve4), using both the uio Pecision s optical an electical igital outputs an US ata souce fom my Mac- ook Po unning on battey powe with Pue Music 3.0 playing WV an IFF test-tone files. pple s US Pobe utility ientifie the N31 as ML US uio Class 2 fom ML kustikgeate, elin, an its seial numbe as Steamlength(tm). The ML s US pot opeate in the optimal isochonous asynchonous moe. pple s uiomidi utility eveale that, via US, the N31 accepte 24- bit intege ata. The optical input accepte atasteams with sample ates up to 96kHz, an the US 2.0, ES/EU, an S/PDIF inputs accepte steams of up to 192kHz. The CD ive s eo coection was goo athe than geat, glitches appeaing in the playe s output when the gaps in the ata spial on the Piee Veany Digital Test CD eache 1.25mm in length at stana tack pitch o 1mm with minimum tack pitch. This was still much bette than the CD stana, the so-calle Re ook, which equies only V V V sec Fig.1 ML N31, Fast filte, impulse esponse (one sample at 0FS, 44.1kHz sampling, 4ms time winow). sec Fig.2 ML N31, Slow filte, impulse esponse (one sample at 0FS, 44.1kHz sampling, 4ms time winow). sec Fig.3 ML N31, Min filte, impulse esponse (one sample at 0FS, 44.1kHz sampling, 4ms time winow). 4 Febuay 2018 n steeophile.com
ML NOLE LINE N31 soun, an the foceful natue of the piano s lowest egiste. This was with the N31 s Min filte. In my inteview with him, Jügen Reis ha tol me that he feels the minimum-phase Min to soun the most musically natual of the thee econstuction filtes. With the MQ-encoe vesions of ob Silveman s ecoing of eethoven s 32 piano sonatas (24-bit/88.2kHz FLC files) souce fom the ND M50.2 music seve, which pefome the fist unfoling (see Jim ustin s aticle on MQ, p.125), thee was a slight inging in the uppe miange with the Min filte that I han t hea with the Rachmaninoff CD. This was euce with the Fast filte, but so was some of the palpability of the piano soun. With this eethoven ecoing, I ene up using the Slow filte, though when I playe the Potlan State Chambe Choi s pefomance of Pucell s Hea My Paye, fom thei Into Unknown Wols (16/44.1 LC file fom CD, CDaby), this filte was a touch too aggessive. In fact, I foun the iffeences among the thee filtes geate in egee than with othe DCs that offe a choice of filtes. The Min filte gave the best balance between pesentation of etail an listenability with Whaling Stoies, fom Pocol Haum s Live: In Concet with the Emonton Symphony Ochesta (16/44.1 LC ip fom CD, Mobile Fielity/&M). I always felt that umme.j. Wilson oveplaye I saw this lineup of the ban in concet in Englan not long afte this album was ecoe but the ML DC with Min filte pevente him fom ovepoweing both the est of the ban an the ochesta. lan Catwight s bass guita in this live ecoing has always soune a bit plummy, but the ML DC etaine the leaing eges of the instument s soun. What about intesample oves? Vince Gill an Paul Fanklin s album akesfiel (16/44.1 LC file, MC Nashville) has been in constant otation hee since its elease in 2013, but like so many ecoings these ays, it has a elentlessly lou quality. The Fightin Sie of Me has some intesample oves, but it in t soun as inmy-face as I m use to though the ML s DC. Was this a benefit of the N31 s igital filte heaoom? When I playe Gaslighting bbie, fom Steely Dan s Two gainst Natue (CD, Giant), it lit up the e clipping LEDs on my 1993-vintage Doough igital-input level mete, which I hooke up to the N31 s ES/EU output. measuements, continue that a playe cope with gaps of up to 0.2mm. The maximum output level at 1kHz was 4.15V fom the balance outputs, 2.04V fom the unbalance, an both outputs peseve absolute polaity. (The XLR jacks ae wie with pin 2 hot.) The output impeance confome to the specification at 198 ohms balance an 93 ohms unbalance. The Fast filte s impulse esponse (fig.1) inicate that it is a conventional lineaphase finite impulse esponse (FIR) type, with symmetical inging eithe sie of the single sample at 0FS. The Slow filte (fig.2) is also an FIR type but is much shote, while the Min filte (fig.3) is also shot but is a minimum-phase type, with all the inging following the single high sample. The Fast filte olle off apily above half the sampling fequency when the N31 ecoe white noise sample at 44.1kHz (not shown), 1 an eache the full stop-ban suppession at 25kHz. y contast, the Slow filte i inee oll off slowly above the auioban (fig.4, magenta an e taces). s a esult, thee was vey little suppession of the aliase 1 My thanks fo Jügen Reis fo suggesting this test, which I have been using fo five yeas. Hz Hz Hz Fig.4 ML N31, Slow filte, wieban spectum of white noise at 4FS (left channel e, ight magenta) an 19.1kHz tone at 0FS (left blue, ight cyan), with ata sample at 44.1kHz (20/vetical iv.). Fig.5 ML N31, Min filte, wieban spectum of white noise at 4FS (left channel e, ight magenta) an 19.1kHz tone at 0FS (left blue, ight cyan), with ata sample at 44.1kHz (20/vetical iv.). Fig.6 ML N31, Min filte, fequency esponse at 12FS into 100k ohms with ata sample at: 44.1kHz (left channel geen, ight gay), 96kHz (left cyan, ight magenta), 192kHz (left blue, ight e) (1/vetical iv.). steeophile.com n Febuay 2018 5
ML NOLE LINE N31 This happene with the woun-up-tight snae um. Of couse, a clippe snae um oesn t soun vey iffeent fom an unclippe snae um; nevetheless, the N31 with its Min filte gacefully epouce this ovecooke tack. In fact, with ole igital ecoings, the N31 soune simply magnificent. I was playing Southen Coss, fom Cosby, Stills & Nash s CSN (4 CDs, 16/44.1; 320kbps C file, tlantic 82319-2). I love the chous of this song, base as it is on the soul-satisfying 1-4-5, tonic-subominant-ominant, epatueiscovey, etun-an-eaffimation blues pogession, but I felt the music wasn t quite matche by the soun quality of the lossy compesse file. ut, as befoe, the N31 allowe sonic shotcomings to step to one sie, letting the ock n oll magic flow foth. n again, the N31 s pesentation of etail was supeb. The quiet solo guita in the song s instumental bige, fo example, stoo clea of the multitacke guitas that accompany it in the efain, but was pesente well behin the louspeakes. The N31 s US 2 input will wok with idevices unning ios7 an up, using the Lightning-US aapte fom pple s Camea Connection Kit. I connecte both my ipa mini an iphone 6S, using the CCK an a long elkin Gol US cable, an note that thei own volume contols wee isable, allowing full-esolution ata to be sent to the N31. pple s Music app will wok fo 44.1 an 48kHz files, while an app such as Onkyo s HF Playe will allow the N31 to play 24-bit files with sample ates up to 192kHz as well as DSD files. The iphone an ipa ae not souces I outinely use in my listening oom, but thei soun quality with both the Music an Tial apps was excellent iving the N31. ecent iscovey on Tial was Daniel aenboim an the Staatskapelle elin s 2016 pefomance of Elga s Symphony 1 (16/44.1, Decca/Tial HiFi). Facebook ecently infome me that Si Thomas eecham egae Elga s music as the musical equivalent of St. Pancas Station, but I love both Elga s woneful Victoian music an the equally woneful Victoian achitectue of Lonon s St. Pancas, especially now that the station has been enovate. With the Tial app on my ipa mini steaming this majestically scoe symphony to the N31, I coul hea no iffeence between this souce an using Tial on the ND M50.2 seve feeing the same ata via S/PDIF to the N31, o using Roon/Tial on my Mac mini via US. Compaisons I fist compae the N31 with the PS uio PefectWave Diect- Steam D/ convete ($6899 with ige II netwok aapte ca), which I bought following the publication of t Duley s eview, in 2014. 3 The DiectSteam DC pehaps sacifices ultimate esolution in favo of a comfotable soun. Compae with the PS uio, an even afte compensating fo the PefectWave s 3.3 lowe level, with the N31 the ML ha a sense of geate ive an impact, especially in the bass. (To make sue the playing fiel was level, all compaisons wee pefome with the NHT PVC use to match levels at 1kHz.) Not only was the ML DC athe moe esolving of ecoe etail, thee was a feeling of ive in its low fequencies with ob Silveman s Rachmaninoff ecoing that mae the PS uio soun too soft. I then tune to the ye QX-5 Twenty ($8950), which I eviewe last ugust, 4 again with levels matche at 1kHz. (The ye s maximum output is 0.7 hotte than the ML s.) The ye s Listen filte is simila in the time omain to the N31 s Min filte, an Silveman s Rachmaninoff sonatas soune vey simila on the two DCs measuements, continue image of a full-scale 19.1kHz tone (cyan an blue taces). The Min filte (fig.5) olle off a little faste than the Slow, but the ultasonic noise floo has an o-looking, scallope appeaance. With the Min filte an 44.1kHz ata, the esponse was flat up to 18kHz but was then 3 at 20kHz (fig.6, gay an geen taces). With the Slow filte (not shown), the olloff began lowe in the auioban, above 12kHz. t highe sample ates with all thee filtes, the olloff continue smoothly until half of each sample ate, at which point the esponse oppe apily. Channel sepaation was >125 in both iections below 1kHz, eceasing slightly to a still-supeb 113 at 20kHz. The N31 s analog noise floo was both fee fom powe-supply elate spuiae an extaoinaily low in level. When I incease the bit epth fom 16 to 24 with a ithee 1kHz tone at 90FS (fig.7), the noise floo oppe by almost 30, meaning that the ML offes 21 bits woth of esolution the cuent state of the DC at. With unithee ata epesenting a tone at exactly 90.31FS (fig.8), the thee DC voltage levels escibe by the ata wee well esolve, as was the Min filte s minimumphase inging at the level tansitions. With unithee 24-bit ata, the esult was a clean V Hz Fig.7 ML N31, spectum with noise an spuiae of ithee 1kHz tone at 90FS with: 16-bit ata (left channel cyan, ight magenta), 24-bit ata (left blue, ight e) (20/vetical iv.). sec Fig.8 ML N31, wavefom of unithee 1kHz sinewave at 90.31FS, 16-bit TosLink ata (left channel blue, ight e). Hz Fig.9 ML N31, spectum of 50Hz sinewave, DC 1kHz, at 0FS into 600 ohms (left channel blue, ight e; linea fequency scale). 6 Febuay 2018 n steeophile.com
ML NOLE LINE N31 in both tonal quality an sounstage pesentation. Gaslighting bbie also soune simila to how it ha though the N31. I on t know how the ye s igital filte eals with intesample oves, but if I ha to swea on it, that ovecooke snae um i soun slightly less natual though the QX-5 Twenty. Finally, I compae the N31 with the VM Ovation MP 8.2 ($10,995), which t Duley eviews elsewhee in this issue an which has a maximum output 4.6 lowe than the ML s. t calle it coectly when he wote that this Geman DC i an exceptional job of allowing the songs as much flow an momentum, an consequent emotional impact, as he hea fom an XTC CD. With the Silveman Rachmaninoff CD-R, an with the MP 8.2 s filte set to Smooth an 176.4kHz upsampling, the soun of the piano was a little moe fowa in the miange, but thee was a little less bottom-en weight. The fowa miange was also a facto with CSN s Southen Coss, with the slight amount of congestion in the backing vocals moe auible than it ha been with the N31. Gaslighting bbie also soune moe fowa than it i though the N31, with a populsive sense of ive an excellent efinition of the bass guita, but the snae um i soun a touch moe aggessive with the MP 8.2 than with eithe the ML o the ye. Oveall, I pefee the ML N31 to the PS uio an VM, though with the ye it was a close call. Conclusions The N31 s absence of a volume contol might be a poblem fo those who ve sol thei peamplifies, as will be the lack of a netwok pot fo those who ve banishe thei noisy NS ives fom the listening oom. n I wish that ML s filtes coul be selecte SSOCITED EQUIPMENT Digital Souces ND M50.2 music seve; ipa mini & iphone 6S with pple Camea Connection Kit; VM Ovation MP 8.2, ye coustics QX5 Twenty, PS uio PefectWave DiectSteam DCs; Mac mini unning Roon 1.3. Peamplifie ye coustics KX-5 Twenty, NHT alance Passive Volume Contol. Powe mplifies ML Coona C15, Pass Labs X60.8 monoblocks. Louspeakes GolenEa Technology Titon Refeence. Cables Digital: uioquest Coffee (DCs), elkin Gol (idevices), US; DH Labs, ES/EU; Espeanto, S/PDIF. Inteconnect (balance): uioquest Wil lue, Canae. Speake: uioquest K2. C: uioquest Dagon, manufactues own. ccessoies Taget TT-5 equipment acks; ye coustics Mytle locks; SC Tube Taps, RPG bffuso panels; Shunyata Reseach Dak Fiel cable elevatos; uioquest Niagaa 5000 Low-Z Powe Noise-Dissipation System. C powe comes fom two eicate 20 cicuits, each just 6' fom beake box. John tkinson with the emote. ut, as I say in the Measuements sieba, igital auio engineeing oesn t get any bette no, I feel, oes igital soun quality. t $15,400 it may be expensive, but ML s Noble Line N31 is beyon epoach. n measuements, continue sinewave (not shown). Not only i the N31 offe vey low levels of analog noise, its istotion was also supebly low. With a full-scale 50Hz tone, the istotion hamonics all lay below 120 (0.0001%), even into the punishing 600 ohm loa (fig.9). Intemoulation istotion was also vanishingly low in level (fig.10), though with the Slow an Min filtes, the aliase images of the 19 an 20kHz tones with which I test IMD wee not well suppesse. The ML s ejection of wo-clock jitte, with all its igital inputs as well as CD (fig.11), was supeb. Digital auio engineeing oesn t get any bette. Finally, as Jügen Reis emphasizes the N31 s ability to cope gacefully with intesample oves, I looke at the CD tack of Steely Dan s Gaslighting bbie using the no-longe-available IS Peak pogam, which oesn t intepolate between samples fo its wavefom isplay. Thee wee inee multiple instances of consecutive samples at 0FS that woul esult in intesample oves. The e aows in fig.12, fo example, show two such instances in the non-intepolate wavefom at 3:27, the one in the left channel (top) having thee consecutive samples at 0FS, an that in the ight (bottom) two consecutive samples. John tkinson Hz Hz Fig.10 ML N31, Min filte, HF intemoulation spectum, DC 30kHz, 19+20kHz at 0FS into 600 ohms, 44.1kHz ata (left channel blue, ight e; linea fequency scale). Fig.11 ML N31, high-esolution jitte spectum of analog output signal, 11.025kHz at 6FS, sample at 44.1kHz with LS toggle at 229Hz: 16-bit ES/EU ata (left channel blue, ight e). Cente fequency of tace, 11.025kHz; fequency ange, ±3.5kHz. Fig.12 Steely Dan s Gaslighting bbie, sample-level wavefom isplay. Re aows inicate consecutive samples at 0FS that woul esult in intesample oves. Poste with pemission fom the Febuay 2018 issue of Steeophile. 2018. TEN: The Enthusiast Netwok Magazines, LLC. ll ights eseve. #C74135 Fo moe infomation on the use of this content, contact The YGS Goup at 800-290-5460.