Sound & Vision - - FRONT PAGE - By Mark Fleis­chmann

MORE PEO­PLE are lis­ten­ing to more di­verse high-res­o­lu­tion au­dio for­mats through higher-qual­ity head­phones than ever be­fore. But ideas about how to feed those head­phones vary. The head­phone amplifier/dig­i­tal-toana­log con­verter, a pop­u­lar hy­brid prod­uct, is among the most tire­less shape-shifters on the au­dio scene. I’ve re­viewed AMP/DACS as com­pact as a USB stick and as big as a full-size rack com­po­nent. At about 4 x 1.5 x 4 inches (WXHXD), Pro-ject’s Pre Box S2 Dig­i­tal falls some­where in be­tween. You wouldn’t carry it in a pocket, but it doesn’t take up much space on a busy desk.


You might know Pro-ject as a pur­veyor of af­ford­able turnta­bles and other phono gear. But the 27-year-old Aus­trian com­pany, distributed in North Amer­ica by Su­miko, also of­fers what it calls the Box De­signs line, which in­cludes DACS, power amps, head­phone amps, and var­i­ous other de­vices. Pro-ject’s Euro­pean arm also of­fers CD and stream­ing play­ers.

As its name im­plies, the Pre Box S2 Dig­i­tal can serve as a stereo pream­pli­fier as well as a head­phone amp and DAC. Pair it with a stereo power amp or a pair of pow­ered speak­ers, and you’ll have a good starter sys­tem. Up to three dig­i­tal sources— USB, coax­ial, and op­ti­cal— can plug into the back panel. There’s no ana­log in­put or Blue­tooth con­nec­tiv­ity, how­ever, so turnta­bles and tablets or smart­phones are out of luck.

The quar­ter-inch head­phone jack on the Pro-ject’s front panel sug­gests that this AMP/DAC is seek­ing to mate with full-size head­phones. Also up front are a 1-inch color sta­tus dis­play, a vol­ume knob, and con­trol but­tons to se­lect in­puts, ac­cess the menu, and se­lect be­tween var­i­ous dig­i­tal fil­ter op­tions. The eight fil­ter set­tings in­clude Pro-ject’s pro­pri­etary Op­ti­mal tran­sient dig­i­tal fil­ter. A small, plas­tic 12-but­ton re­mote du­pli­cates the front-panel con­trols, adding mute, bal­ance, and trans­port. (A more sub­stan­tial metal ver­sion is avail­able for $79 ex­tra.) The chas­sis, front panel, and even the but­tons are all pale gray alu­minum, giv­ing the lit­tle box a solid feel.

Through its USB in­put, the Pre Box sup­ports up to 32-bit/768khz files in PCM for­mats, and DSD via PCM up to DSD512, which cov­ers any dig­i­tal file you’re likely to buy or stream (and then some). The dig­i­tal coax­ial and op­ti­cal in­puts sup­port files with res­o­lu­tions up to 24/192. One of the Pre Box’s in­ter­est­ing fea­tures is MQA sup­port, which I'll dis­cuss in more de­tail later. When play­ing files with MQA, the dis­play shows the MQA logo plus a blue dot in the up­per right cor­ner. MQA is sup­ported only through the USB in­put; the com­pany says im­ple­ment­ing it through the other dig­i­tal in­puts would have in­creased the cost of parts and boosted the Pre Box’s price.

Un­like most DACS in this price range, the Pre Box fea­tures dual (ESS SABRE) DACS and sep­a­rate left/right sig­nal paths. Other dif­fer­en­ti­at­ing fea­tures in­clude a new pro­pri­etary clock de­sign, ul­tra-low jit­ter, and a com­bi­na­tion of ac­tive and pas­sive fil­ter­ing to elim­i­nate noise from the USB out­put feed­ing the DAC.

The Pre Box can be pow­ered di­rectly via most USB con­nec­tions, or you can use the in­cluded ex­ter­nal power sup­ply. MQA and DSD play­back re­quire in­stal­la­tion of a com­puter driver from a sup­plied CD-R. Oth­er­wise, the Pro-ject is

ready to go for Win­dows 10 and Linux. Most Mac OSX ver­sions are sup­ported ex­cept for El Cap­i­tan and Sierra.

As­so­ci­ated equip­ment that I used for my test in­cluded Hi­fi­man Edi­tion X V2, Sennheiser HD600, and Sony MDR-V6 head­phones. I also used a Len­ovo Win­dows 10 desk­top PC run­ning Foo­bar 2000 li­brary soft­ware for file ac­cess, and Tidal Hifi for hi-res stream­ing.


Dur­ing my lis­ten­ing, the Pre Box’s per­for­mance was char­ac­ter­ized by an ad­mirably clean and un­fa­tigu­ing top end, though it could be frus­trat­ingly ret­i­cent with higher-end head­phones. In a day spent with the Hi­fi­man, for in­stance, it of­fered plenty of easy lis­ten­ing but not much sparkle. Flip­ping through the nu­mer­ous fil­ter modes did lit­tle to al­ter this first im­pres­sion. The Pre Box didn’t hit its stride un­til I plugged in the Sennheiser and the Sony cans, whose dis­tinct but vastly dif­fer­ent sonic per­son­al­i­ties were per­mit­ted to emerge.

I hadn’t ex­pected much from the Sennheiser: it has a ret­i­cent top end of its own and I’d ex­pected that the com­bi­na­tion with the Pre Box would be overkill. In­stead, their mu­tual smooth­ness in the pres­ence re­gion let me push the vol­ume up enough to com­pen­sate for the Sennheiser’s mod­est bass, mak­ing the sound big­ger and beefier than it nor­mally would be in ev­ery­thing from sym­phonic sta­ples like Beethoven’s Fifth (Car­los Kleiber, Vi­enna Phil­har­monic, 24/88.2 FLAC) to rock stom­pers like Led Zep­pelin’s “Black Dog” (24/92 FLAC). Im­ages, though not strongly out­lined, were gen­er­ously scaled, beau­ti­fully fleshed out, and darkly col­or­ful, giv­ing ex­tra in­ten­sity to lushly ar­ranged tracks like Nick Drake’s “River­man” and “Hazy Jane II” (24/96 FLAC).

The Sennheiser HD600 was the least sen­si­tive model I used and re­quired the Pro-ject to play at the top of its vol­ume range, usu­ally – 15 to – 8 on a scale of

– 80 to 0. But I heard no sense of strain. In­ci­den­tally, the Pre Box and the Sennheiser share a list price of $399. Don’t make too much of that; I’ve heard ex­pen­sive head­phones sound great with in­ex­pen­sive amps and in­ex­pen­sive head­phones sound great with ex­pen­sive amps. The Sony MDR-V6, which costs only a quar­ter as much as the al­ready rea­son­ably priced Pre Box, has a tre­ble-for­ward sound that formed a per­fect yin-yang with the Pro-ject amp. Play­ing David Ch­esky’s “Ben’s Farm in Ver­mont” (24/192 FLAC), my go-to track for high-fre­quency fin­ery, the chim­ing per­cus­sion in­stru­ments were not just au­di­ble, but in­te­grated into a bet­ter mu­si­cal flow than I can re­call hear­ing with any pair­ing of head­phones and amp, and I’ve played this track through many. The Nick Drake tracks were beau­ti­fully im­aged, al­beit in a dif­fer­ently bal­anced way. The Sony/pro-ject combo also shaved off the dig­i­tal edges from Richard Thomp­son’s home-stu­dio-recorded “They Tore the Hip­po­drome Down” (24/88.2 FLAC) to get at its bit­ter­sweet mu­si­cal essence.


The Pre Box pro­vided me with my first chance to do ex­tended lis­ten­ing to MQA (Mas­ter Qual­ity Authen­ti­cated) as de­liv­ered via Tidal stream­ing. MQA is a com­pu­ta­tion­ally in­ten­sive (and some­what con­tro­ver­sial) lossy au­dio codec that can “fold down” the ul­tra­sonic con­tent of bulky hi-res au­dio sig­nals, re­sult­ing in Cd-sized files and streams. I tried to com­pare MQA stream­ing with non-mqa files, con­cen­trat­ing on tracks du­pli­cated in Tidal and my hi-res mu­sic li­brary. Of course, this was an ap­ples-and-or­anges com­par­i­son— I could never be cer­tain that both were sourced from the same mas­ter. But one dif­fer­ence im­me­di­ately ob­vi­ous with all three head­phones was level— the MQA tracks were in­vari­ably louder, even with vol­ume con­trols maxed in both apps. I used the Pre Box’s vol­ume con­trol to roughly match lev­els. In a few cases where Tidal car­ried both MQA and non-mqa ver­sions, the MQA ver­sions were still louder.

While the stronger sig­nal al­most cer­tainly gave the MQA streams a sub­jec­tive ad­van­tage, the Pre Box al­ways ex­hib­ited ex­cel­lent be­hav­ior at the top end of its vol­ume range. Stick­ing with the MQA ver­sions, Kleiber’s Beethoven was warm yet up-close, a com­bi­na­tion I don’t of­ten hear, and I felt the world-class Vi­enna Phil­har­monic string sound was col­or­ful, and re­al­is­tic. Nick Drake’s vo­cal on “Hazy Jane II” and the back­ing vo­cals on Don­ald Fa­gen’s “Max­ine” fol­lowed the same course, seem­ing less me­chan­i­cal and more cor­po­real.

While these impressions held true for all three head­phones, the main ben­e­fi­ciary was the Hi­fi­man, whose per­for­mance pro­gressed from just ac­cept­able to truly in­volv­ing. My past ex­pe­ri­ence sug­gests that it of­ten ben­e­fits from in­cre­men­tal im­prove­ments in hi-res au­dio for­mats. MQA got a bet­ter than pass­ing grade from the Sennheiser and Sony, but with the Hi­fi­man, it turned up aces.


The Pro-ject Pre Box S2 Dig­i­tal of­fers a step up in per­for­mance with low- to medium-priced head­phones, and it makes for an es­pe­cially good match with those that have a tre­ble em­pha­sis. It also serves as an in­tro­duc­tion to MQA. If it errs, it does so on the side of com­fort and lis­ten­abil­ity. You’d have to spend a lot more to im­prove on Pro-ject’s Pre Box S2.

Newspapers in English

Newspapers from USA

© PressReader. All rights reserved.