John
March 2012. An audiophile-grade hi-fi system in a suitcase. Hand delivered from Chicago, that’s what Michael Goodman dropped into my lap a couple of months ago. An impressive way to introduce the CEntrance’s Audiophile Desktop System’s party trick: portability.
“I started in audio electronics when I was 14 when I built my first power amplifier. At 17 I built my first drum machine to practice my synth with. Later I supported myself through college by running a stereo repair shop out of my apartment. That was back in Russia, where I couldn’t really do my dream job — record bands. After my family came to the US in 1988, I worked at one of Chicago’s famous recording studios Paragon Recording, which was responsible for the sound of Styx, Ohio Players and many others. Since then I put together and ran my own Jazzfunk Studios which did a lot of commercial work and recorded underground rock bands. I also studied and then started playing bass in jazz bands around town and soon realized that my heart was on the musician’s side of the proverbial glass. During all that time, I worked at Shure and converted that company to digital as one of their leading hardware engineers. I left as manager of their hardware engineering group. That’s when I started CEntrance and the rest is history.” That’s Goodman’s story – from technologically curious teenager to CEntrance’s head designer and MD. CEntrance has grown its consumer audio division by first establishing a solid grounding in the pro market.
Inside the rough-tough Pelican case are 2 x MasterClass desktop loudspeakers, a DACMiniPX (amplifier/DAC/head-amp), speaker cable and switch-mode PSU. A complete rig no less. The rugged plastic case (familiar to photographers) has internal foam padding cut to house each of the components. Yes, it’s included in the US$2k sticker price. Goodman had brought the whole shebang as carry-on luggage on his flight(s) from the USA to Australia.
April 2012. I was a week away from moving house. Everything I own was slowly being packed up and away. Into boxes went my $2k budget rig: Audio-gd NFB-2.1, Rega Brio-R and Epos ELS-8. In came CEntrance’s A.D.S.. The ‘D’ word tells you at where this package is pitched. The website says for ‘near field use’. The rubber feet do indeed reflect the desktop inclination of the design. I took them beyond that. The MasterClass were placed immediately out of their comfort zone and onto stands. The A.D.S. ran as my main system for that final week in my old abode. I didn’t feel as though I’d downgraded: what I surrendered in room drive and propulsion I gained in transparency and musical insight. A sideways move then.
Mix it up, break it down…
The MasterClass 2504 standmounts are specified as capable of 50Hz-20KHz. They are a two-way bookshelves in the truest sense: one could plant them on a shelf. The coaxial driver arrangement is not so common, especially in the intended desktop niche. The 4″ mid/bass driver and deeper-set tweeter are push-me-pull-you-d by the same magnet. Goodman explains: “The speakers are matched up with the amp (or vice versa) in several important aspects:
“1. Power handling capability. The amp’s output is limited right at the edge of speakers’ full power rating. It’s almost impossible to clip the speakers and yet we push them to the max, so you get maximum loudness and no distortion.”
“2. Frequency response. While the amp in the PX features a linear frequency response and can drive most speakers, we took into consideration the loading effects of the passive linear crossover in our MasterClass 2504 speakers in tuning the power and transient handling capability. We know that this amp will have enough damping factor for our speakers to avoid the pesky mid-bass resonance, which messes up the frequency response.”
“3. Distortion. Coaxial transducers, and especially co-incident, or as we call them “coplanar” transducers are very revealing of non-linearities in the audio. They feature very low phase distortion because the highs and the lows originate at the same spot and reach your ear at the same time. We had to invest extra money and go with a low-noise and low-distortion amp design to take advantage of this revealing capability of the speakers. The amp doesn’t add any distortion, which one could previously get away with because it would be masked by the speakers, but not with these…”
Part-conclusion right up front: the MasterClass are midrange darlings. Standmounts that are more brain than brawn; there’s a head-in-singer’s-mouth intimacy to Paul Simon’s “Homeless”. Robyn Hitchcock’s complex guitar work on “I Saw Nick Drake” is cleanly cleaved into individual note plucks, which in turn gives more space in which the accompanying acoustic bass line swirls. Hitchcock’s vocal is permitted room aplenty to meander midway – and slightly behind – the speaker plane. Everything in its right place without the ugly jostle for position/attention; a transducer un-phased by complexity. All the angst-soaked drama that tunnels to the core of Death Cab For Cutie’s “We Looked Like Giants” remains intact. At times edgy (especially during such intense chorus climax), but predominantly thrilling.
When DACMiniPX-powered, the MasterClass slice music delicately and so present MORE layers for the listener to savour. Same ham, sliced more finely.
Monolake’s Ghosts. Bass reach and all-round heft is limited in larger living spaces. The Masterclass don’t quite the connote the sheer physicality of the title track in the ultimate (read: chest thump) sense. For their size – and in small/medium rooms or close proximity – low frequency impact is more than adequate. Hardly surprising given the constraints of enclosure and driver size. On the spookier second cut “Taku”, the Masterclass mainline the requisite eeriness – that’s that immersive midrange depth again. The higher-frequency contributions to synthetic instrumental decay ice the cake. They miss none of the subtly layered click, clanks, clangs, pings and pongs. Detail within electronic music is Robert Henke’s strength; he creates worlds in which to submerge the listener. If you don’t feel as though you’re piloting the Mars rover when listening to Monolake, you need a better system. Here, the CEntrance standmounts draw one over the martian surface so that we feel every twist and turn of a painstakingly layered mix.
Quality over quantity is the CEntrance other-worldly order. Think of them as sitting halfway between a JohnBlue JB3 and a 47Labs Lens, but much closer to the latter in terms of detail retrieval and overall clarity. Bass doesn’t go as low as the Lens, nor are they as dynamic/bouncy/fun. The JB3 often sometimes lose definition and shapeliness below the waist – their mid-bass is warmer and fatter. Not so MasterClass. Their mid-bass doesn’t crowd out or thicken. But neither do they drive the room as well as the JB3. Near-field operators won’t care – they’ll be too busy swimming in a lake (but not quite an ocean) of sound. The MasterClass also best the JB3 for treble extension and the sensation of recording space ambience.
CX –> PX. CEntrance’s forerunning DAC/head-amp DACMiniCX has been augmented with an amplifier stage to give us the DACMiniPX. Oh, and it’s black (not silver). Volume attenuation takes place in the analogue domain. A rocker-relay switch bounces the user through three digital – and one analogue – inputs: USB, coaxial, optical and line-level. Output on the rear is via loudspeaker binding posts or a pair of line-level RCAs. PC/Mac via USB, Squeezebox/Sonos via coaxial, Airport Express via optical, iPod via (gasp-shudd
er) line-in…everyone’s covered.
“The speakers and the amp visually appear from the same family. It took a long time to match up the aluminum to the wood (two surfaces that can’t really be matched up) but we did our best. You may have noticed that if you sit the PX on top of one speaker, the slant at the top of the speaker allows you to easily adjust the volume while at the same time keeping the knobs hard to bump (they are inset).”
Given the small chassis that already contains a Class-A headphone stage and a DAC, it’ll come as no surprise to seasoned audiophiles that the PX’s amplification stage is 25wpc of Class D. Those lusting for transparency will find much to enjoy from the PX, particularly with suitably efficient loudspeakers. Hooked up to the MasterClass 2504 the sound is clean and lean. Each musical layer is thinly carved – not a criticism, but a compliment. Those wanting tubular romance, or a thicker sonic sauce should look elsewhere. The A.D.S. has a polite formality. Being upstanding and correct is its modus operandi.
“The Class D power amp is our own and is based on the newest technology from Texas Instruments (CEntrance is an official 3-rd party design house for TI, so we get access to the newest stuff first). Our design features lowest noise and super-low distortion. The digital outputs go through two stages of extra filtering to minimize RF interference and filter out all the grungy high-frequency components, leaving only audible frequencies on the wire.”
“Speaking of the wire, we are actually upgrading the Audiophile Desktop System soon with specially designed Reserve Series speaker cable. Initial tests of the production samples are very encouraging – more spacious sound, better definition, tighter bass on more openness in the highs. I will send you a pair of cables as soon as they become available.” I skipped out on the very basic stock speaker wire and used Peter Graves’ red stuff [Grave Science].
Let’s step it up.
DACMini PX with Zu Omen. This amplifier brings clarity and separation but surrenders body. Heft is dialled downward, transparency upward. More resin bite can be heard on cello strings and – Class D’s best card – bass drum kicks are more cleanly rounded. With the Sansui bass can be more mushy pea than green bean. The higher-efficieny Zus don’t require much to get going – this Mini’s 25wpc is more than enough. Playing hard and fast with dynamic excitement it only takes a volume turn to 10 O’Clock to get the Omen out of bed and dressed; they are as rewarding at lower volumes as high. CEntrance’s DACMiniPX is a more than worthy amplification partner, most notably during quieter late night listening sessions. Even with a SMPS brick no background hash was noted. Its flair and detail flicker with the Zus sees it capable of countering anti Class D snobbery at this price point.
Can-jamming. I asked Goodman how the DACMini’s headphone stage stacked up against the bus-powered DACport.
“Yes, the DACport is a feat of engineering optimization, but it’s not perfect. DACport is running off USB, which gives us the maximum limit of 2.5W of power to play with. Naturally, we didn’t want to take all the power to ourselves and run at the edge — Firstly, some USB ports may start cutting off the hungry peripherals if they came too close to max available power. Secondly, we wanted to extend the laptop’s battery life for our customers, so we’ve chosen to only use about 2W in DACport, when driving headphones hard. At normal listening levels it runs below that.”
“During the design phase we had to be really careful in partitioning that power budget between the analog and the digital circuitry. They each ended up getting about one half of the available budget. Roughly speaking, Digital (USB, converters) needs a watt and Analog (Amps, power supplies) gets the remaining watt when running at max level.” “DACport takes the 5V digital from USB and ramps that up internally to +/-9V for the analog circuitry using modern, low-noise switch-mode converter circuits. The value of +/-9V was a tight compromise, which ensures plenty of level in most situations. However this may not be enough power to drive some current-hungry headphones (Hi-Fi Man comes to mind.)”
“With DACmini, the internal rails that the circuitry is running at are extended to +/-17V, which is much closer to the power conditions found in professional audio equipment. DACmini can drive practically any headphones and we have happy customers in the Beyerdynamic, Sennheiser, Grado, Hi-Fi Man and Audeze camps.” “The other benefit of running a higher voltage rail in DACmini is the more linear circuit, which translates to lower distortion. Lastly, DACmini features a more stable, better filtered power supply, which results in tighter, more solid bass.”
The aforementioned heft-transparency trade is mirrored in headphone mode also. Immediately switching the AKG K-702 from Sansui AU-417 quarter-inch socket to CEntrance quarter-inch socket, the midrange steps forward, imaging solidifies – we get more crisp-crunch from Byrne/Veloso acoustic guitars.
The AKG K-702 are a notoriously fickle customer. Get the amplification wrong and they sound thin and un-involving. The DACMiniPX goes where other all-in-one-rs (Anedio D1, Peachtree iNova/iDecco) have previously come up short. The dynamically thrilling joyride of Squarepusher’s new release sees Tom Jenskinson is firmly back in the electronica camp. If you were disappointed by Daft Punk’s Tron Legacy soundtrack, Ufabulum is intense, playful and spasticated! Letting it run on endless repeat it was downright obvious that the AKG don’t go undernourished with the PX. The CEntrance feedbag easily matches the solidly-made and solid-sounding Burson HA-160 for drive and musical saturation. Using the right-hand socket on the Australian, listener satisfaction is achieved on both amps with the volume placed squarely at midday. They are more similar than different: a shorter signal path with the PX direct (no interconnects, y’see) means detail is bright eyed and bushy tailed. Instead, sound routed via Burson + WLM interconnects surrenders a smidgen of minutiae extraction in favour of some transient rounding and warmth. Swapping CEntrance for Schiit on the DAC front brings more fullness/fatness to the yard. Head-fi-ers who like ’em big n bouncy will dig the Schiit/Burson combo the most. Listeners who crave the scientific blade of neutrality will prefer the PX as an all-in-one. Somewhere in the middle lies the PX + HA-160 combination.
DAC matters: (I suspect) a careful balancing of the DAC vs amp see-saw has been implemented within the PX. When [recently] comparing the John Kenny DAC Sabre and DAC32, the PX was deployed as a control unit. Sonically, the PX splits the Kenny twins’ differences down the middle: not as bitter-sweet/lemon-sharp as the JKDAC Sabre but not as stoned (yes, marijuana) as the JKDAC32. It isn’t as sun-drenched as the former nor is it as autumnal as the latter. The JKDAC Sabre connected via the line-in on the PX gives up too much fruity cheek-suck on leading guitar edges – ouch. The DACMini’s internal decoder is far more measured/considered without overly surrendering on its raw detail trawl.
Much like the tube-d up Peachtree iNova/iDecco, the CEntrance’s top-end tenderness lends itself neatly to those with real-world digital audio collections. Collections that contain MP3s. You won’t get aural glass shards from your 160kbps-encoded Black Flag collection here. A shade of late-summer warmth coats the highest frequencies of the PX DAC. Scaremongers might scream of roll off. Compared to other delta-sigma’d designs they have a point, up TO a point. Treble doesn’t break th
e skin with the sharpest incision of (say) a Bel Canto or a Musical Fidelity. However, in the context of a thinner-blooded amplification stage, it makes sense. No high-frequency smoothing or sanding presents itself once the MasterClass return to the fray.
That said – and doing my best NOT to self-contradict – the PX-as-DAC can’t be so easily dismissed a ‘musical’ (which is all too often used euphemistically to defend against a lacking of inner-resolve). Knife edge transient blunting aside, most would label the CEntrance decoder as ‘neutral’. One definitely wouldn’t describe it as romantic. (Considerably) Closer to the Metrum Octave than the Schiit Bifrost, this decoder’s real talent lies in drawing the listener inside the music; rather than the JKDAC Sabre-way of pushing details from the inside to the out.
Also of significance is the USB implementation. The DACMini PX permits up to 24/192 over S/PDIF and up to 24/96 over USB…which is driverless because – wait for it – it isn’t asynchronous, but adaptive. Gasp! The sky doesn’t tumble down. Michael Goodman’s adherence to making adaptive USB sound as good as it does has seen him licence this proprietary “Adaptiwave”/”Jitterguard” firmware to the likes of Dan Lavry, Steve Nugent (Empirical), Paul McGowan (PSAudio) and John Stronczer (Bel Canto). These are big hitters to have stand behind your software skills – enough muscle using adaptive – not async – bats to knock jitter clean out of the park. Pragmatism > Idealism. It doesn’t matter how you clean-up the jitter as long as you do so. Goodman’s Jitterguard tech essentially buffers the (irregular) incoming data before sending it (re-clocked) on its way to the DAC chip. The theory could not be simpler.
The introduction of a USB-S/PDIF convertor lifts the PX DAC’s game above that of the USB. (Prior to which, they’re pretty evenly matched). In the context of this system’s simplicity and portability, adding another box runs contrary to its spirit of minimisation. I lived with the PX/Masterclass combo running together without ever feeling I were missing something; or missing OUT on anything. This CEntrance system needs to stand together alone…and it stands its ground. For the six weeks it spent as my second system in my new abode, I found it to be engaging and resolving. Moreso than the Rega Brio-R and JohnBlue JB3 that it supplanted. In the context of the outgoing rig, the A.D.S solicited listening notes that broadly translated to “open”, “neutral” and “clean”.
And perhaps that is why CEntrance’s Audiophile Desktop System kicks goals. It’s an above average achiever in contexts broader than its desktop marketing pitch. For this reviewer’s non-audiophile buddies, this would elevate it above and beyond expectations of a first system. To be fair, it would possibly bust their budget too. If you’ve been around the audio block more than once, you’ll know that quality like this is tough to snatch from the jaws of small change. Not that $2k is a back of the sofa amount. One could self-bundle JohnBlue JB3, a Rega Brio-R and a Schiit Bifrost for similar outlay. That particular combination flows with warmer, thicker blood, sounds more congealed and is far less musically immersive. Moreover, it doesn’t ship with its own flight case – anyway, the Rega integrated might render it too heavy for carry-on luggage. It wouldn’t be portable. You could slip in a Miniwatt N3 or Trends TA-10.2, but then you wouldn’t have a head-amp.
With an audiophile system-in-a-suitcase, CEntrance have done something that’s so face-palm obvious that it has us collectively muttering (as we often do about the very best innovations) “Why didn’t I think of that?”. It’s the Weber Baby-Q of the hifi world. This design brief demanded a scaled down product without a surrendering of quality. One could drop both the Weber and A.D.S. into the car for a weekend away of high-quality BBQ food AND high-quality sound reproduction. Whilst it might have been originally intended for small gatherings in intimate spaces, it can be stretched to accommodate larger functions. I’m talking ’bout both A.D.S. and the Weber – loaves and fishes, people! One could take the A.D.S. interstate (the flight case falls inside hand-luggage size and weight limits) or – spreading the audiophile word – carry it to a friend’s house to demonstrate to them (in their space with their music) that good sound can matter. Students – wake up! The A.D.S. has university dorm-room written all over it. Yup, CEntrance are another company taking the game to the kids.
On a personal tip. I’m not as interested in the high-end as I am in quality hifi gear that better lends itself to modern, smaller living spaces. Think of medium-high density living where people occupy units/flats/apartments with poor wall/floor insulation. Is this not where Joe Schmoe resides? Is that not where most of the world’s population is headed? For such spaces, you don’t want floor-shaking subwoofers teamed with piss-weak satellite speakers. Leave those cheap and nasty 2.1 setups to the likes of Logitech. CEntrance’s Audiophile Desktop System is what I’d take if I were to live in downtown Osaka. OR if I were to head back to the UK for an extended vacation. OR if I needed a quick-quality setup at work. OR a hotel room. OR at a friend’s place. OR if I needed a hi-fi up and running in a jiffy in new digs. With the A.D.S. one can take a GREAT sound into the nooks and crannies of the world with ease – for these are the places that need it most. An audiophile system-in-a-box that far surpasses desktop audio expectations. Hats off!
Associated Equipment
- Squeezebox Touch
- Empirical Audio Synchro-Mesh
- JKDAC (Sabre)
- JKDAC32
- JKSPDIF MK3
- Metrum Octave NOS Mini
- Schiit Bifrost
- Rega Brio-R
- Burson HA-160
- John Blue JB3
Audition Music
- Robyn Hitchcock – A Star For Bram (2000)
- Paul Simon – Graceland (1985)
- Monolake – Ghosts (2012)
- Death Cab For Cutie – Transatlanticism (2003)
- Squarepusher – Ufabulum (2012)
- David Byrne and Caetono Veloso – Live At Carnegie Hall (2012)
Further Information
