Wadax Pre 1 Mk 2 Digital Preamplifier
by Roy Gregory | April 7, 2014
© www.theaudiobeat.comFor as long as digital sources have existed, manufacturers and audiophiles alike have been trying to banish the line-level preamplifier to the dustbin of history. As digital technology has advanced and proliferated, the arguments in favor of digital signal storage, transfer, processing and integration have finally risen from a mutter to an irresistible clamor. Yet the situation is not without irony. Its not the sheer unassailable quality of digital reproduction that has won this day, but the fact that the audio source has been subsumed into the wider digital universe of network computing. At the same time, digital media (of any stamp) are yet to topple analog replay at the pinnacle of musical reproduction. High-res files might be jostling for elbowroom at the summit of audio standards, but theyve recently been joined there by the resurgent output on reel-to-reel tape. That might indicate many things, not least the affinity of boys for their toys and the stubborn, almost bloody-minded conservatism of the existing audio consumer. But it is also an inescapable reality. Logic might dictate the elimination of analog storage and replay from the audio landscape, but the market clearly has other ideas.
Part of this reality arises from the performance of existing digital-control solutions. Historically, the likes of Goldmund and Meridian have demonstrated impressive results, but they have also strained the limits of bandwidth and processing power, meaning that customers not only have to buy into a total-system solution but that the system itself is expensive and can be highly volatile -- instantly undermining the ease of use, versatility and interfacing arguments that underpin the supposed sonic benefits of digital control. Even in its simplest form (a DAC with multiple digital input options and a variable analog output) it is only recently, in the shape of the Jeff Rowland Aeris and dCS Vivaldi, that I have experienced digital controllers that can stand comparison with the alternative of feeding a fixed analog output into a good analog line stage -- and dCS have been at this for a long, long time!
If we have finally reached the tipping point at which digital system control becomes a reality, the point at which the products on offer actually start to find their way into a critical mass of end-user systems, then it will in part be because digital engineers have finally accepted the necessity of taking analog seriously, both in terms of execution and as a source. No product in my experience marks that realization more clearly (or positively) than the Wadax Pre 1, a single-box control unit that really is a system control center for all men and all seasons.
Its digital Jim, but not as we know it
While its tempting to dive straight into the range of facilities, capabilities and options that set the Wadax Pre 1 apart from the crowd, in many ways thats not the place to start -- at least not if you want to understand why this product could, indeed should succeed where so many have failed. Key to the intrinsic quality of the Wadax is not what it does but the manner in which it is done: in other words, the overall ethos and governing aesthetic. Before this is a digital product, or a system-control product, it is first and foremost a high-end product, not just in terms of cost but in terms of execution. That is what defines and underpins its performance and ultimately its success.
Starting on the outside, lets look at the basic form and construction of the Pre 1. As Ive already said, this is a single-box unit -- but what a box. The substantial base chassis that contains the audio circuitry is milled from solid billet aluminum and is covered by a second milled case that drops over it like the top of a shoebox, the whole clamped, clamshell construction creating a dense, inert capsule for the audio circuits. The contrasting front panel is a model of minimalism, offering just two beautifully weighted rotary controls and a large central display. An engraved top plate is rebated into the cover, its brushed metallic finish matching the knobs and contrasting with the monochrome paint and Nextel finish of the case. The result is classy, clean and understated, while the whole 22kg (49-pound) chassis rests on four stainless-steel cone feet, indicating just how seriously Wadax take the issue of mechanical energy and draining it out of their product. And yes, you did read that correctly; despite its compact dimensions and digital nature, despite the fact that this is a preamp, it weighs in at grunt-inducing, think-before-you-pick-it-up weight of nearly 50 pounds -- as much as many solid-state power amps -- a fact that alone should be sufficient to give you pause for thought. Not only are these guys serious, theyre taking audiophile sensibilities seriously too.
But the Pre 1 is weighty for a reason, and that reason is the way it has been put together. The casework isnt just an example of never mind the quality, feel the width; it has been carefully considered and optimized with the sole intention of minimizing the intrusion of self-generated mechanical energy into the signals being processed. It signals an awareness that is rare in any form of audio electronics design, but especially rare in the world of digital, where so many designers obsess over the inner workings of clocks and digital transfer while assuming that the considerations of analog circuitry are secondary and that their data is immune to external influence.
The second epiphany comes when, having succeeded in lifting the Wadax Pre 1, you take a look at its back panel. I think it is fair to say that Ive rarely come across any array of input and output socketry quite as densely (or confusingly) packed as this! Fear not; the sheer number of sockets on show isnt nearly as daunting as it first appears, and in reality their type and variety are the second thing that sets this product so firmly apart. Twenty-eight sockets of multiple types is quite a lot to take in -- especially on a digital product, where most inputs or outputs only require a single connector. Look a little closer and it all starts to make sense. Getting your head around whats going on isnt helped by the muted-gold anodized labeling on the chromed back panel, but thankfully theres a very necessary and very clear layout map in the manual. Essentially, viewed from the rear, inputs are top right of the back panel, outputs bottom left, with an unmarked diagonal division between the two. As per usual, the output options embrace both digital and analog, but are unusually comprehensive. There is a pair of Wadax variable digital outs (on RJ45 network sockets), as well as BNCs for S/PDIF and an auxiliary clock output, and two complete sets of variable analog outputs, each with balanced and single-ended options.
Where things get really interesting (and what makes this a genuine control unit) is when you get to the inputs. Most obvious among these are the BNC and two RCA sockets for S/PDIF, along with a TosLink optical and USB. But there are also three XLRs (one of which is an AES/EBU balanced digital input) and six further RCAs -- just to confuse you. Those extra inputs are -- hallelujah! -- designated for analog sources; and not just line-level either. Finally, theres an RJ45 streamer input for connection to a network, but more on that later. The Wadax Pre 1 can be configured to accept two line-level analog inputs on single-ended RCAs, or one of those inputs can be superseded by the option of an internal phono stage capable of accepting MM or MC cartridges on either balanced or single-ended inputs, a rear-panel switch allowing you to select from three different gain settings.
Time for a brief recap: what we have here is a dual-function A to D and D to A, capable of selecting and switching between five digital inputs, as well as the internal Hermes streamer, and two analog inputs (with a further option for a seriously sophisticated internal phono stage). Thats impressive enough, but believe me it only scratches the surface of what the Wadax Pre 1 can do if you let it. Its onboard processing potential is huge and allows it to not only eliminate non-linearities in your record player but also to act as a time-and-phase-corrected digital-domain crossover for the Wadax digital interactive loudspeaker system. The phono stage alone is revolutionary in its implications, and Ill be reviewing that in a separate article that covers not only what this remarkable phono stage can do, but what it can tell us about the very real musical impact of cartridge setup and alignment. Normally, the very idea of passing the fragile analog signal from your record player through the digital domain and back again would fill me with horror, but in this case the results speak for themselves.
For now, Im going to confine myself to considering the Wadax as a combined digital and analog system controller -- because lets face it, even thats weird (and challenging) enough. There have been plenty of analog line stages that include an internal DAC, but a system controller that executes its myriad powerful functions entirely in the digital domain, irrespective of the nature of the source signal, that is different indeed. Meridian and Wadia have both offered this option via separate, standalone A-to-D converters, but the Wadax, by including the facility as standard, finally embraces the inconvenient reality of analogs continued rude health. In some respects, the nearest thing to the Wadax is probably the original Devialet unit, but the two are not to be confused, separated as they are by their underlying attitudes. The French integrated amplifier leans forward toward the realms of home automation and network audio, compromising performance in the name of style and execution. The Wadax almost leans backward, unmistakably part of the high-end separates tradition -- and it performs accordingly. Its not the casework that makes the Pre 1 a genuine high-end product, and its not the range of functions. Its not the different input or output configuration options. Its all of those things. Its the way that Wadax has understood the issues -- their range and complexity -- and succeeded in amalgamating them into a single, versatile, high-performance whole.
Ive been lucky enough to use the Wadax for some considerable time, a period in which it evolved from Mk 1 to Mk 2 status, further lengthening the review process. What I can confirm is that the evolution to the Mk 2 version is sonically and musically impressive. Changes to the power supply, processing algorithms and analog output stage have resulted in a significantly more purposeful sound, with greater presence, impact and better image localization. Finally, the Hermes streamer, a $4300 option on the Mk 1, is now fitted as standard, bringing file replay under the control of the same master clock as the other digital processes. Assume that all comments from here on refer to the Mk 2. Rolled together, these improvements have lifted the performance dramatically, and owners of Mk 1 units should seek an upgrade urgently.
The upside from the review point of view is that this prolonged evolution has meant that Ive been able to listen to the Pre 1 with and alongside a whole host of critical components, including the Wadia S7i, the dCS Paganini (transport, DAC and clock), the Naim UnitiServe and the Rowland Aeris DAC, the Connoisseur 4.2LE line and phono stages and the VTL 7.5 III. Thats a pretty star-studded lineup of established high-end performers, each in its own specific category. Yet, like an athlete competing in the heptathalon, the Wadax is being measured against the best in each event and expected to meet their standards. Not just that, its being asked to do so for a lot less money. The basic Wadax Pre 1 (without phono stage) costs $32,100, which given its sheer versatility and functional range, definitely places it in bargain territory. Just add up the combined cost of the competitive products necessary to do the same range of jobs to the same standard and youll see what I mean. The fact that Ive embarked on such wide-ranging comparisons should tell you a lot, but even I wasnt expecting the Wadax to emerge with its honor not just intact but significantly enhanced.
Different is as different does
The only way to approach a product as versatile as the Pre 1 is systematically -- and even then there will be capabilities you wont cover in depth, and some you wont cover at all. The full Wadax system solution, with source- and room-mapping through corrective processing, is way beyond the scope of this review. Just keep in mind the possibility as a further indication of just how capable and future-proof this product is. In the meantime, lets concentrate on the basics and that means starting with the Pre 1s performance as a DAC -- which isnt quite as simple as it seems. If you just want to hear the Wadax DAC then that means cranking the volume to max and running it into a conventional analog line stage. So far so good, except that the Pre 1s own analog output stage is still in the circuit and able to do the same job. Lets ignore that for a moment or were going to get well and truly lost.
Running the Wadax as described leaves you in no doubt whatsoever that this is one excellent DAC -- which is just as well, given that every other aspect of its performance depends on its digital engineering. Characterized by its lack of character and genuine neutrality, the Pre 1 has both immediacy and an immediately engaging quality that frees musicians and their performance from the constraints of the recording. It brings a warmth and substance to the music that is too often absent from digital replay systems, but it does it without sacrificing digitals traditional strengths. This is a presentation that is long on clarity and control, but is also firmly grounded, with a natural sense of ebb and flow. It shares many of the underlying qualities that made the Rowland Aeris so appealing, placing it firmly in a select group of new-generation digital products that achieve a level of musical engagement that previously escaped digital replay.
My initial listening for these comparisons centered on the Wadia S7i and The dCS Paganini DAC, my benchmark digital components. Using the Wadia as a transport and the Connoisseur line stage, I first compared the Wadax to the Wadias own internal DAC. With both units carefully level-matched (using the Pre 1s level control and an SPL meter), I listened to a whole range of different recordings back to back, although to be honest it was a largely unnecessary process after the first few bars of the very first disc. The Wadax cleared this first hurdle like a pole vaulter faced with a high-jump bar. Its amazing how many digital components fail this basic test, the S7i seeing off some pretty illustrious components, banished in no uncertain terms by its combination of substance, presence, convincing dynamics and fluid presentation. The Wadax took the musical foundation and integrity that typify the Wadias sound and extended them -- significantly. The increase in separation and transparency, depth and weight, tonal color and the sense of musical and spatial coherence amounted to a whole different level of performance -- both sonic and musical.
Ill use the Mozart Sinfonia Concertante as an example. Playing the Decca gold CD [Universal 4806263], the Wadia is its usual confident self, solid in every sense of the word. But inserting the Wadax into the equation brings an obvious and musically dramatic change. Whereas the Wadia makes the Oistrakh father and sons performance seem stolid and worthy (a case of art imitating reality?), the Pre 1 reveals a far more impressive musical vista. The carefully structured orchestration of the opening, one of Mozarts most precise and carefully poised passages, springs to life, Kirill Kondrashin conjuring unsuspected verve and gusto from the Moscow Philharmonic, an orchestra now clearly laid out across the soundstage and beyond the speakers. The increase in width is matched in the depth perspective, and each element of the orchestra is now clearly defined in space, within a single coherent acoustic. But perhaps the biggest change to the overall presentation is at low frequencies, an increase in depth, weight, shape and transparency on which the whole performance quite literally rests. The orchestration doesnt depend on the scale or power of its lower registers, but instead wants the poise and restraint that allows those little flourishes and nudges that Mozart uses so deftly to add this intended extra impetus or calming influence to the energetic exchange of musical phrases. The Wadax brings an effortlessly elegant control and intent to both the playing of the bass section and Kondrashins direction, a clarity that reveals the purpose, pace and complex layering of this opening passage, the way it transitions so gracefully from orchestral crescendo to solo exchange.
But even more telling is the playing and presentation of the soloists themselves. If the opening exchanges are impressive enough, in the second movement Andante, the Wadax reveals and revels in the almost telepathic relationship between the Oistrakhs. Davids majestic poise and sumptuous tone finds its perfect foil in Igors understated yet flowing lines, while the differing tonality of violin and viola are instantly apparent. Where some players leave you wondering which instrument is playing, until the other enters, the richer, smoother body of the viola and the contrast between the violins agility and the bigger instruments more progressive bowing are instantly apparent, clearly identifiable. In common with many concerto recordings, the solo instruments are over-voiced (and over-separated) here, an exaggeration that makes the lead contribution easier to follow and more obviously important. Yet, in an almost counterintuitive step, rather than further widening this gap the Wadax delivers a far more natural sense of the violins (and violas) voice and scale, in the context of the orchestra as a whole. The result is a performance thats more convincing, more akin to reality and far more engaging.
So much for the competition presented by a good one-box solution. How about the Pre 1s peer group? Firing up the dCS Paganini was, if anything, even less of a test. Details attended to (level matching, filter selection on the dCS and identical connection configuration -- the dCS only offers RCA S/PDIF inputs, mandating a BNC/RCA adapter) comparisons commenced and it was immediately apparent that the differences were even greater. This doesnt reflect the relative quality of the dCS and Wadia DACs, but rather the fact that while the Wadax and Wadia are cut from at least similar cloth, the dCS comes from the opposite end of the digital spectrum, all resolution and digital detail, stark with Cinemascope separation. In contrast, the Wadax is almost warm and cuddly -- except that it suffers none of the cloying softness or rounding that description usually suggests. Listen carefully and you realize that the Pre 1 actually resolves more detail and delivers more information. In other words, its not just the amount of detail on offer but the way it is assembled that makes the presentation more natural in terms of perspective, weight, musical flow and tonality. Where the dCS collapses the tonal distinctions between the two solo instruments, the Wadax paints them clearly, defining both the tonal differences between the two but also the tonal palette within each instrument. So that in the Andante, it traces the way that the tonal character of David Oistrakhs instrument traverses from lilting to plaintive, a facet of the performance missed by the vast majority of digital-replay systems.
Digital technology moves and develops with almost alarming speed, and it should be pointed out that this comparison crosses a generational boundary. I suspect that history will come to define dCS product as pre- or post-Vivaldi and, despite upgrade to current spec, the Paganini platform is beginning to show its age; but there is no mistaking the fact that the dCS DAC sounds almost deconstructed beside the more wholesome, organic performance of the Wadax. Of course, Im also taking the Paganini DAC outside the context of its own transport and (more importantly) clock, but the fact remains that the Pre 1 is demonstrably right at the leading edge of digital replay performance, joining the likes of dCSs own Vivaldi, the Rowland Aeris and doubtless a few others Ive yet to discover, in delivering a previously unsuspected level of musical insight and involvement from basic silver disc. As Ive already noted, thats reassuring, given the critical role played by the Pre 1s core digital technology in everything that it does.
If the character a component brings to individual instruments and performers helps to define its own performance, the ability to differentiate between the style and sense of different performances is just as critical, revealing the extent to which a unit imposes its own voice on proceedings rather than allowing each performance to speak for itself. Comparing the 1963 Oistrakh/Kondrashin Sinfonia Concertante recording to the 2007 performance by Julia Fischer with Yakov Kreizberg and the Netherlands Chamber Orchestra [PentaTone PTC 5186 098] is fascinating. With over 40 years between them, its hardly surprising that fashions have changed, with the sparser, more modern style of the Fischer performance clearly apparent. But what really stands out is the difference in the central relationship between the two solo instruments. Fischer is characteristically brilliant: precise, deft and confident. But the viola of Gordan Nikolic is simply not in the same class, creating a very different artistic dynamic. Where the Oistrakhs present a conversation between equals, Fischer leads and Nikolic struggles to follow. It alters the whole weight and sense of the piece in a way that was far more apparent via the Wadax than ever before. The Rowland Aeris went some way in this regard, but it is a kinder and more musically forgiving observer of the performances nuance and inner chemistry. The Wadax is a long, long way from warts and all, but it is unflinchingly communicative, cutting right to the heart of the relationships within the music. Thats why the orchestral structures that drive the opening passage are so effective. Its not just the soloists stood front and center that get the treatment, its every aspect of the recording. The perfectly judged and weighted energy of those double basses, the way they subtly push or pull the tempo and dynamic envelope represents a relationship with the orchestra every bit as important as the relationship between the soloists -- its importance is just not quite as obvious.
After that, catchin shrimp was easy
What the Wadax DAC brings to digital replay is a sense of order and structural clarity -- a place for everything and everything in its place. This organizational aptitude stretches from bottom to top, creating a natural and unforced quality to recordings. You are no longer struggling to relate one part to another, to subconsciously shuffle the elements into the right pattern. What applies in the spatial realm applies with a vengeance in the temporal, which is what accounts for the Pre 1s easy grasp of pace and tempo, its rhythmic agility and expressive range. Once you put your finger on what the Wadax is doing, it becomes increasingly obvious the more you listen -- as does its absence.
Intrigued by the fundamental difference between the Wadax presentation and that of so many other digital players, I arranged a series of blind comparisons with a range of different listeners that pitched the Pre 1 Mk 2 against four alternatives, including price peers. Shorn of the comfort blanket of product identity would they pick the Wadax out of the crowd and would they value its qualities as highly as I do? If anything, the sense of natural weight and order was even more apparent under blind listening. Nobody failed to pick the Pre 1 and all clearly favored it over the competition -- by no small margin. Most reactions were along the lines of a fairly emphatic, "Ill have this one please." Pressed as to why, the alternatives were characterized variously as thin, insubstantial, aimless and, most tellingly of all, as deconstructed. Was this rigorous and double-blind? Not to lab standards, but it didnt need to be. What I was interested in was whether or not what Id identified as a fundamental performance trait really was that important in a wider, non-reviewer/non-audiophile context. The answer was a pretty unequivocal yes -- the Wadax is different and in this case that difference translates as better. Other units in the test included those already mentioned as well as my GWSC-modified Wadia 861SE and a Metronome Technologie C5, so hardly pushovers. Yes, some are more successful than others, but the Wadax was consistently superior across the board. Not a strict product comparison -- especially given the range of prices and functional options on offer -- what I was wondering was whether the Pre 1 Mk 2 would communicate more clearly and directly under these conditions, reinforcing my impression that it simply makes more sense of the signal.
The intricate, interlocking phrases of early classical compositions obviously play to any product that excels when it comes to unearthing the musics structural underpinnings. How does the Wadax fare with more fluid or elastic material; does its grasp on space and time free the musicians or impose its own tyranny? You dont get much more challenging than Coltranes A Love Supreme [Impulse IMP 11552], with its elongated lines and clashing tempi. Its always been a challenge for digital systems, but its a test the Wadax sailed through with almost contemptuous ease. This musical stream of consciousness flowed so effortlessly that it simply sucked me in. I forgot the supposed challenge right from the opening bars and reveled instead in the performance unreeling before me. For once, the half-muttered vocals of "Acknowledgment" actually made musical sense, the shattered tempi of "Resolution" built on each other rather than falling apart, Coltranes anguished sax anchored by McCoy Tyners confident piano.
The sonic collage of Jocelyn Pooks Flood [Virgin 72438 4815O 28] combines swirling atmospherics and plainsong to create almost mystical soundscapes, their ethereal presence almost devoid of structure. Yet the Wadax pieces the fragments together with a deft touch, revealing the underlying and interlocking patterns that make music out of what would otherwise be noise. Lets face it -- making music from material as diverse as the cawing of rooks, subterranean industrial rumbles, Arabic song and the Kyrie is no easy task, but its one that both Pook and the Wadax master, creating soundscapes that are at once immersive and compelling. At the other end of the spectrum, the folk-rock roots of reggae might seem as traditional as it gets, the result as formulaic as it comes, but that is to ignore the creative capabilities of Sly, Robbie and the rest of the Compass Point crew. Black Uhurus 1981 album Red [Island 846 567-2] demonstrates just how much latitude the reggae conventions allow, from the rocky, upbeat "Youth Of Eglington" to the laid-back, Spartan groove of "Rockstone." But its the echo-laden "Sistren" that really stretches the envelope, exploiting Michael Roses skat singing style and the instrumental agility of the backing musicians, to create a rhythmic and melodic skeleton that passes responsibilities from one player to the next without ever over-filling the mix. Its a track that needs a firm grip on the temporal domain to keep all the parts in place, but once again, the Pre 1 deals effortlessly with this exacting track, as effortlessly as it lays down the rock-solid footings for a track like "Journey." Impressively and infectiously motive, this is the perfect example to play anybody who questions the concept of pace, rhythm and timing.
If piano is the ultimate instrumental test of any audio system, its run a close second by air guitar. No joke -- any system that really works will be built on communication and that includes the infectious capability to make those dance who probably shouldnt. Marginally less embarrassing and certainly easier to carry off while retaining a modicum of self-respect, wigging out on imaginary lead should be an almost irresistible urge given the right material. Im guessing that Floyd is the obvious standby, but if you want really over-the-top guitar pyrotechnics that still retain that seriously dirty, sweaty edge that makes rock work, then give Rick Neilsens assault on "Aint That a Shame" (from Cheap Trick At Budokan [Epic CDEPC 86083]) a go, the artillery barrage of percussive support delivered by Bun E. Carlos just adding to the fun. Again, the Pre 1 doesnt disappoint. It doesnt remove the nasty edge from Neilsens guitar riffs and it doesnt mute the shrill adulation of the capacity crowd. The unstoppable momentum of the drums relentless cannonade just pushes the whole track even further into the musical red. If audio equipment should be able to offend and upset, then Wadax have definitely ticked that box, making the Pre 1 Mk 2 all the better for it.
What makes the Pre 1 so musically expressive and effortlessly revealing? Or to put it another way, why does it succeed where so many digital products fail? As Ive already suggested, part of its performance is rooted in the completeness of its design, the fact that it treats issues like the power supply, casework and analog output stage just as seriously as it does the number-crunching. That means that excellence in one realm of performance isnt undermined by weaknesses elsewhere. But having said that, theres no escaping the fact that the Pre 1s digital engineering is revolutionary in concept.
Input to the Wadax is either analog (via a TI PCM4222 24-bit A-to-D) or digital, but either route ends up presenting a digital data stream to the TI 1794/2 DAC. But before it gets there, that digital signal is passed through a proprietary Wadax 128-bit ASICS (Application Specific Integrated Chip Set) that embodies a dynamic model of the error characteristics of the TI DAC. To quote designer Javier Guadalajara:
For A/D and D/A conversion, we chose two devices that are readily available on the market: the PCM4222 and the TI1792A. These offer the best results for our purposes. A/D and D/A chips are never ideal and all exhibit a non-linear behavior that show up in different ways, depending on signal and surrounding circuitry conditions. The same can be said of I/V, anti-alias and output stages. So we can consider the whole signal chain as a black box. This black box is then accurately modeled using 128-bit mathematics. The result is a multi-dimensional matrix of parameters and numbers. This matrix is what we call a "map," as it captures all the necessary information to predict the output (and the error) in every possible situation. The ASICS then correct for the predicted error by using feed-forward techniques. In essence, we are avoiding the problems by preventing them from appearing.
What this explanation does rather gloss over is the expertise, engineering and investment required to make the approach work. Perhaps the best example of this is the ASICS chips themselves. The bandwidth and processing power demanded by the 128-bit algorithms is such that specific chips, purpose-built to carry those algorithms, are essential to any practical implementation. To achieve the same result using Field Programmable Gate Arrays would need upwards of 50 LSI chips; even if such a circuit could be made to work, the space required precludes the possibility. Now just consider what it costs to create a custom chipset.
To boil down this approach to its simplest possible form, the model incorporated into the circuit, can predict the error introduced by the DAC and other circuit blocks, and apply the necessary feed-forward correction. Because it also understands that the DAC behaves differently under different load conditions, it is able to adapt accordingly, all without resorting to conventional feedback techniques -- along with their associated problems. All of which is pointless if you erode the resulting signal integrity with poor transfer or interfacing. By bringing all of the digital functions inside a single chassis (including the Hermes streamer) they can be close-coupled to a single master clock, significantly reducing jitter levels across the signal path. The analog output from the DAC is then passed through an I/V stage and anti-alias filter before reaching the discrete analog output stage. Volume control is achieved through a hybrid solution, employing both digital scaling and sliding gain in the output stage, rather than conventional attenuation. This gives incredibly precise 0.5dB steps without any loss of resolution, the level translated to a numerical readout on the main display.
Of course, any digital feed-forward system depends on the accuracy and sophistication of the model employed and the algorithms that incorporate it. But get it right and the results can be remarkable -- as demonstrated emphatically by Goldmunds Project Leonardo, a corrective system for time and phase error in passive crossovers. I have no way of judging just how accurate the Wadax model is -- except by results. The fact that the Pre 1 consistently delivers more convincing, more stable and more natural music than more conventional approaches pretty much speaks for itself. The resulting performance does exhibit a more convincing and consistent soundstage and significantly better rhythmic integrity, suggesting greater phase coherence and lower timing errors. Although I have to take the technological description on trust (and although it comes with impeccable academic credentials -- just see the sidebar) the results are only too audibly explicit.
Its always nice when the backstory equates so directly with what you hear; its even nicer when it promises to illuminate a genuine way ahead, with the startling clarity of a pair of bi-xenon headlamps -- and is steerable too!
To boldly go. . .
By now you should have got the idea that Wadax have produced a DAC thats both capable and musically versatile. Nothing I threw at it caught it out -- and that includes source components too. As well as the Wadia transport I also used the dCS Paganini with considerable success -- and not a little regret that I couldnt employ its SACD replay facility. But I suspect that the really pressing question on many lips will fasten on the USB input and file replay. For high-res file replay, Wadax offer the network-based option of a 32-bit/192kHz-capable Hermes streamer, preferring to bring all data handling aspects in-house rather than depending on external streamers or computer sources. The standard USB input will accept files at a maximum data rate of 24 bits/48kHz. That might seem disappointing in the context of todays numbers-driven digital arms race, but what I can report is that the USB input worked flawlessly connected to a MacBook Air, running Pure Music and a mix of downloaded and ripped material.
For high-res file replay I had access to two different options, the Naim UnitiServe, loaded with both 24-bit/96kHz and 24-bit/192kHz files and feeding the BNC input, and the MacBook Air feeding the Hermes streamer via the RJ45 network connection. As an aside, I have to say that Naims one-box streaming solution has an awful lot going for it. Utterly fuss-free and sonically stable, the iPad interface is a joy to use and the UnitiServe has seen far more action in my system since its arrival than any other computer-audio source. In terms of sound quality, its replay of standard ripped Red Book material doesnt compare to the substance, body, space and sense of musical purpose offered by the S7is transport -- but then it costs an awful lot less and Red Book replay isnt really its raison dętre. With 2TB of onboard storage and wireless control via the household network, its the combined appeal of distributed music and high-res replay that will sell this unassuming and incredibly cost-effective little box.
Linked to the Wadax, the Naim worked perfectly, the input auto-switching to the file frequency each and every time, ensuring full-bandwidth replay without the endless rigmarole of checking and rechecking Midi settings. Yes, I know they are supposed to be stable and capable of auto-selecting the highest available data frequency, but its alarming how often they seem to default to 44.1kHz, requiring manual override. Yes, there are probably ways of ensuring their stability, but until I find them, the UnitiServes unflappable performance remains attractive -- as does its potential sound quality. Potential? Yes, potential -- because the first thing you discover about high-res file replay is that not all high-res files are created equal. In fact, aside from the kind of audiophile recordings available from specialist record labels, quality seems to drop off at an alarming rate, entering free-fall anytime you approach mainstream music. Thats not the charts and pop, its the broad vistas of the established rock, pop, jazz and classical back catalogues. Not to put too fine a point on it, I seriously struggled to find examples of music I really wanted to listen to in genuinely high-res formats -- and a number of the albums I did download proved distinctly disappointing. Thats not the fault of the UnitiServe or the Wadax, which can only work with the files they are fed. On the rare occasions that file quality matched the material the results were remarkably impressive, but until the consistency of the supply situation improves, high-res downloads remain a reviewing necessity rather than a source of musical enjoyment. The good news is, that once that happens, the Wadax is certainly capable of delivering the musical goods.
The best results I achieved (in musical terms) were from a 24-bit/192kHz file of Cat Stevens Tea For The Tillerman and several DGG classical downloads, but most notably, the Kleiber Beethoven 5th/7th Symphonies, encoded at 24 bits/96kHz. Its somewhat ironic that both of these are drawn from analog originals, but so far Im struggling to find high-res digital originals that are worth listening to. However, what these files do demonstrate is that the Wadax DAC is just as happy and just as impressive at higher bit rates as it is operating at CD resolution.
Of course, to really test the Pre 1s file replay capabilities, I need to hook it up to a dedicated network and its own off-board NAS drive storage unit. That takes it outside the context of conventional system configurations, introducing a host of new considerations and issues. It also reflects a geographical division when it comes to configuring computer audio interfaces; in the US the USB has become the de facto standard, while in Europe, network based solutions retain their popularity. As a result Ill be looking at the Hermes streaming solution (and some of the issues that it raises) at the same time as I assess the capabilities of the phono stage. However, one pressing question that can be cleared up right now; currently the Pre 1 offers no DSD replay capability, although like all things computer related, that may well change.
Having placed the Wadax Pre 1 Mk 2 under the microscope of direct digital comparison, seeing how its DAC stacks up in isolation, it was time to let it spread its wings. The first step was to remove the Connoisseur line stage from the chain, allowing the Wadax to assume responsibility for the system-control functions of source selection, level control and driving the power amp(s). Whilst many companies have offered and even promoted this path, with variable outputs fitted to their DACs and CD players, it is only recently that the performance achieved has come close to or exceeded the inclusion of a decent line stage. Again, the Rowland Aeris broke the mold on this one, while, when it comes to driving amplifiers direct, the Vivaldi has also demonstrated a significant step up in performance over dCS's previous DACs. Well, now you can add the Wadax to that list.
Comparing the performance of the Pre 1 Mk 2 driving power amps direct to its unattenuated output played via the Connoisseur 4.2 LE or VTL 7.5 Series III line stages is a sobering experience. Its not that the Wadax is better than the two established high-end units (although, as is the way of things, it is better in some respects) but the ease with which it holds its own that's significant. Play something essentially simple, like Neil Youngs Silver and Gold [Reprise 9 47305-2] and the differences are clearly apparent. Line the Wadax up against the Connoisseur, match levels and away you go. The Pre 1 Mk 2 cant match the sense of warmth, immediacy and musical momentum that has always been the Connoisseurs forte, but it gets surprisingly close, while adding its own particular strengths to the mix: instrumental separation and definition, the seamless coherence of the soundspace, the ability to remain in control of the signal without exerting constraint on the music. It might not have the same level of expressive freedom that the Connoisseur conjures -- or let the music breathe in quite the same way -- but it brings a calmer, more defined and in some ways more intelligible perspective to events. The hybrid VTL preamp sits between the two solid-state units, with its own sense of poise and authority, body and weight. But what all three have in common, what is most important about their performance and what separates them from the crowd, is their ability to step aside, allowing more direct, more intimate connection to the music and musicians.
Stepping up to more complex and demanding material widens the gaps, underlining the sheer energy of the Connoisseur, the stability and grounded authority of the VTL, the definition and calm control of the Wadax. On the Testament issue of the du Pré/Barbirolli performance of the Elgar Cello Concerto, recorded live by the BBC in Prague [Testament SBT 1388], the Connoisseur brings a more physical quality to proceedings, du Prés cello substantial, her bowing bold, almost graphic in its positive intent. In contrast the Wadax is more restrained, setting her back amongst the orchestra, with a broader, more inclusive perspective viewed from Row M or N as opposed to the Connoisseurs Row E or F. The Pre 1s soundstage is better developed and more clearly defined, the elements of the orchestra more clearly spaced and placed. On orchestral tuttis the Connoisseur gives a greater sense of the explosive energy of the live event, and the Wadax does a better job of retaining the placement and spatial relationships within the orchestra.
I could run through a whole playground of musical swings and roundabouts, but the devil here isnt in the details. The salient and slightly alarming fact is that the Wadax Pre 1 Mk 2, for all its complexity, its inclusion of digital processing and its single-box format, can happily stand comparison with two serious high-end heavyweights -- in precisely the role in which youd think it would be at its weakest and where traditionally those weaknesses have been exposed.
So far so good, but now its time for the game-changer. The cherry on the icing on the Wadax cake is those analog inputs, allowing it to incorporate analog sources as well -- the stumbling block thats tripped all previous digital control units. But the Pre 1 doesnt just offer analog switching through to its output. Because the control aspects of the unit are all handled in the digital domain, the analog inputs are passed through an internal A to D that converts them to digital signals that are then handled by the same circuitry as the digital inputs. Whoa! Converting analog to digital just to convert it back again? Does it get any more counterintuitive than that?
Thats exactly how I reacted -- until I actually embarked on a bypass test, running the analog outputs of the Wadia S7i through the Pre 1 Mk 2's inputs and out into the Connoisseur, and comparing them to a direct link, S7i to Connoisseur. The sound through the Wadax was actually better! It was crisper, cleaner, clearer and better separated and organized. The energy in the playing was more concentrated and more directed, with a greater sense of purpose, all of which sounds unlikely until you remember that the Wadax DAC contains some very clever digital-domain algorithms. Whether they have a "corrective" influence or not, I cant say. Maybe its the additional drive into the Connoisseur thats delivering the improvement, but it was utterly consistent and it was consistent across sources too. I dont use an analog tuner because my FM reception is so bad, but I was so bemused by these results that I fired up my Revox PR99 reel-to-reel and played previously recorded live concert broadcasts and achieved exactly the same improvement. The analog inputs on the Wadax are a long, long way from being just a convenience or an afterthought. They are just as carefully considered and just as impressive as everything else about the Pre 1 Mk 2. To really succeed, this product has to be both sonically exceptional and exceptionally even-handed. It is.
But thats illogical
In one sense its a case of you pays your money and makes your choice. My preferred concert seats are F20/21, and perhaps not surprisingly, no line stage has yet shaken my preference for the Connoisseur. In absolute terms I can discuss the minutiae of audio and musical performance, bestowing cost-free judgments with the same abandon that wedding parties dispense rice and confetti. But there also comes a point where you have to ask, "How much?" and where the ugly question of price raises its head. When I look at the Wadax Pre 1 Mk 2, at its incredible versatility and remarkable capabilities, it definitely gives me pause for thought. Yes, I can run the Connoisseur line stage with its matching phono stage -- or the VTL TL7.5 III and TP-6.5 -- teamed with the Jeff Rowland Aeris (a high-end bargain if ever there was one), creating a five- or six-box setup that will handle most of my analog and digital switching and sorting requirements. But at what price? Or I could run the Wadax Pre 1 Mk 2, a single-box unit that fulfills all the functions of the complex multi-box setup as well as adding a few more that are far from trivial, does them to a comparable standard and at a seriously more approachable price. Throw in the cost of the cable and accommodation requirements that go hand in hand with the more complex setups and their financial burden starts to become unsustainable.
Of course, reality isnt quite that simple, and the equation that can include quotients for price and passion simply doesnt exist. Anybody paying these prices for audio equipment has already committed well beyond the point of cool, considered logic. That person probably already owns some or all of the functionality embraced by the Pre 1 Mk 2s multi-talented versatility, a factor that will impact on any consideration of value. But reality also exists on different planes. At its most basic level, Wadax need the Pre 1 Mk 2 to compete in the marketplace and generate sales. Thats a task its more than adequately equipped to carry out. In fact, I can see quite a few uneven contests being stopped, as the Pre 1 Mk 2 effectively kicks in doors and takes no prisoners.
On a more abstract level, the Pre 1 Mk 2 signals the final, belated arrival of a new product category. We have been talking about the inherent potential of digital processing and system control since the advent of CD. Now -- finally -- we have a product that genuinely realizes that potential. The Wadax Pre 1 Mk 2 is up there with the best DACs Ive used. It compares favorably with the best and most esoteric line stages and it allows switching and control of both analog and digital source components. This is no computer playing at audio. This is a genuine high-end component, built to high-end standards, run through with high-end thinking, and make no mistake, it offers genuine high-end performance. If high-end audio is about no-compromise engineering and performance, then you dont get much higher end than this.
First of its kind maybe, but the Wadax Pre 1 Mk 2 is going to be a hard act to follow, not least because, as Ive already suggested, there is more to come. If the Pre 1 Mk 2s performance as both DAC and line stage is both surprising and gratifying, its optional internal phono stage is nothing short of astonishing -- technologically and musically. Thats why its getting its own review. Meanwhile, theres a new kid on the digital block; for now she may be talking quietly, but what shes saying is well worth a listen. Compact and incredibly powerful, stylish and perfectly balanced, the Wadax Pre 1 Mk 2 really is the Jess Ennis of audio.
Prices: $32,100, $38,000 with phono stage.
Warranty: Three years parts and labor.
Francisco Remiro, 2 -- Ed D3 28028 Madrid, Spain
Who is Javier Guadalajara?
A product as complex and potentially groundbreaking as the Wadax Pre 1 Mk 2 doesnt just appear out of nowhere. The background and accumulated experience behind it are crucial to its chances of success -- both musical and commercial.
Wadax designer and chief engineer Javier Guadalajara has a fascinating business and academic background. Based in Madrid, his family has a long history in the audio industry. His father brought B&O to Spain in the 1970s and went on to become one of the countrys leading high-end distributors, handling many high-profile brands, including Goldmund.
Meanwhile, having grown up in a world full of esoteric high-end audio equipment, the young Javier was working his way through higher education, with a degree in telecommunications engineering followed by post-graduate studies in the fields of acoustics and electronics, culminating in a position as Associate Professor of Electroacoustics. His subsequent research into digital sound reproduction ("The Effects of Jitter in Digital Audio," AES Iberian Section) led to a professorial post at Universidad de Deusto.
It was this combination of his constant involvement with the family business and the evolution of digital sound and processing, as well as his academic work, that was to lead him back to the audio industry. His experience with Goldmund both convinced him of the potential in advanced digital electronics and feed-forward techniques and showed him the frustrations of dealing with unstable products and systems. In the end, it doesnt matter how good something might sound if it doesnt work reliably and the backup isnt there. In 2006 he established Wadax and launched its first product, the Pre 1, in 2010. In 2013, the company was awarded the prize as Best Startup by Europes top business school (Instituto de Empresa).
He is widely published in the fields of digital audio and video electronics, programming and the Internet, with both academic studies and books to his name, and he has written and taught courses in analog and digital electronics.
Analog: VPI Classic 4 turntable with SDS; VPI JMW 12.7 and Tri-Planar Mk VII UII tonearms; Lyra Titan i, Scala, Dorian and Dorian Mono cartridges; Clearaudio Goldfinger Statement cartridge; van den Hul Condor cartridge; Allnic Puritas and Puritas Mono cartridges; Nordost Odin tonearm lead; Connoisseur 4.2PLE phono stage.
Digital: Wadia S7i and GWSC-modified 861SE CD players, dCS Paganini and Vivaldi transports, Metronome Technologie C5 DAC.
Preamps: Aesthetix Janus Signature, Connoisseur 4.2, VTL TL-7.5 Series III Reference.
Power amps: Aesthetix Atlas Signature Stereo, Berning Quadrature Z monoblocks, Jeff Rowland Design Group Continuum S2 integrated amp, Naim NAP 300 stereo amp, VTL MB-185 Signature Series III monoblocks.
Speakers: Avantgarde Trio, Coincident Speaker Technology Pure Reference Extreme, Wilson Benesch Square Five, Raidho C1.1, Focal Scala Utopia V2.
Interconnects and speaker cables: Complete looms of Nordost Odin, Crystal Cable Absolute Dream or Ultra from AC socket to speaker terminals. Power distribution was via Quantum QRT QB8s or Crystal Cable Power Strip Diamonds, with a mix of Quantum Qx2 and Qx4 power purifiers and Qv2 AC harmonizers.
Supports: Racks are Hutter Racktime or Quadraspire SVT Bamboo. These are used with Nordost SortKone equipment couplers throughout. Cables are elevated on Ayre myrtle-wood blocks or HECC Panda Feet. Nordost Sort Füt units were used under the speakers.
Acoustic treatments: As well as the broadband absorption placed behind the listening seat, I employ a combination of the LeadingEdge D Panel and Flat Panel microperforated acoustic devices. These remarkably simple yet incredibly effective acoustic panels have become absolutely indispensible when it comes to hearing what the system is actually doing.
Accessories: Essential accessories include the Feickert protractor, a USB microscope and Aesthetix cartridge demagnetizer, a precision spirit level and laser, a really long tape measure and plenty of masking tape. I also make extensive use of the Furutech anti-static and demagnetizing devices and the VPI Typhoon record-cleaning machine. The Dr. Feikert PlatterSpeed app has to be the best ever case of digital aiding analog.