List Price: $1,280


Review by

Dr. John Richardson

You know what they say about sequels, right? 


Yep, you got it, the sequel never lives up to the quality of the original.  But what if it did? What if, even given the riveting quality of the original, the sequel offered more action, better acting, a snappier soundtrack, and an all-star cast?  Nope, time to wake up; it never happens.


Don’t tell that to the folks at Rein Audio of Germany, especially when it comes to DACs.  You might recall that I reviewed Rein Audio’s first DAC, the X-DAC, awhile back.  I gave it a nice review based on its overall sound quality and solid construction.  Maybe not the best, but a solid contender nonetheless, especially at its price point, which was around $750 usd that fit into our famous "Stereo for Cheap Bastards"  category, or gear that sells for less than a thousand bucks. Good as it was, the X-DAC did leave me with a bit of consternation, as didn’t quite meet its competition in some regards, namely due to its lack of a native 110 V power supply (I had to use a step-up transformer) and its less sophisticated usb interface which did not handle high resolution files.  A very musical device, but just not quite up to snuff for the competitive U.S. market at the time of its release.  I conveyed my concerns on to Rein Audio’s Jason Tornald, and as we shall soon see, it is apparent that they didn’t fall upon deaf ears.


When I was recently offered the chance to hear the next DAC in Rein Audio’s sequence, I have to admit that I was intrigued.  Might the sequel actually be better than the original?  If it were, it would certainly be a DAC to be reckoned with; something that could really whet the appetites of well-heeled (and picky) audiophiles everywhere. 


Enter, then, the Rein Audio X3-DAC, and prepare to be impressed...


Upon first laying eyes on this beauty, it was obvious that this fella was going to be in a somewhat different league than its predecessor.  Gone were the two rotary knobs on the original X-DAC, replaced by a back-lit fluorescent display and a series of four push button controls on the front panel.  From left to right, these are the power switch, source selector, digital filter selector, and up-sampling selector.  That’s correct:  you get six user selectable digital filters and optional up-sampling.  I really like that last one, as some folks prefer to up-sample their digital data, while others (myself included) like to keep playback at native sampling rates.  Anyway, it makes sense to keep it optional (some DACs don’t).  More about these features later.


Flipping our little DAC over yields a nicely packed rear (did I just say that??).  Outputs include both unbalanced RCA and balanced XLR options, and inputs provided are coaxial, toslink (optical), and AES/EBU in addition to the usb 2.0 option.  All RCA jacks are chassis mounted using teflon insulators, providing plenty of structural integrity.  The overall build quality appears to be first-rate, and the unit is quite hefty due to its internal toroidal power supply, which does handle our 110 V line voltage here the good ol’ U. S. of A.  There is no indication of where the unit is assembled, so I’m going to still assume that it is built somewhere in Asia.


On the interior I found a nicely laid out topology consisting of high quality components.  The DAC chip itself is, like in the original X-DAC, of the Wolfson variety, specifically a pair of WM8741 chips.  Also used are Analog Devices AD797 operational amplifiers in a balanced configuration as the output stage, the same as in the X-DAC.  The innards, as far as I can tell, aren’t that much different that those of Rein’s previous DAC, so the question emerges:  how different would it sound?  Are we just looking at an upgraded feature set, or an altogether different animal here?  Well, let’s see....


My evaluation system was kept quite simple, consisting of my REDGUM RGi60ENR integrated amplifier powering a pair of Fritzspeaks Rev 7 speakers (review forthcoming).  On the source side, I used my Mac Mini with Channel D’s Pure Music Audio Engine tossing the bits over to a Sound Devices USBPre2 audio interface via a YFS Reference two-headed usb cable.  The USBPre2, which served as a usb to S/PDIF digital converter, was powered externally using a YFS 5V linear power supply.  From the USBPre2, the digital data were sent to the Rein Audio X3-DAC via its coaxial input.  I also tested the X3-DAC’s usb input directly using my MacBook Air.


DACs on hand for comparison purposes were my Antelope Audio Zodiac (powered by an 18 V custom linear power supply from YFS Audio) and the internal DAC on my Sound Devices USBPre2 unit.


Before I got down to any real serious evaluation of the X3-DAC, I went back and reviewed my notes on the original Rein X-DAC.  Aside from my mild griping about the feature set, I was pretty impressed with its sound quality.  The X-DAC was unfailingly musical, with somewhat soft, but never boring, presentation.  As I mentioned in my review, it was a DAC you could put in your system and pretty much forget about, as it didn’t draw unnecessary attention to itself.  Looking back, I enjoyed my time with the X-DAC.


I have to say that I feel pretty much the same way about Rein Audio’s X3-DAC.  It’s a real winner in the musically satisfying category given that it likes to stay in the background of my system doing what it does best:  making beautiful music.  Most of my listening was done using the coaxial input, as I mentioned a bit earlier, and the results were always smooth and detailed, yet relaxing to the ear.  Like the original X-DAC, the coaxial input will accommodate PCM files of up to 192 kHz native sampling rates.  I also looked back at the music I used to evaluate the X-DAC and thought it might be fun to use some of those same selections to assess its newer sibling.


Up first was “Un Poco Loco” an interesting album from vibraphonist Bobby Hutcherson that is sort of an interesting mix of prog rock and jazz fusion.  After getting to know the album pretty well, I’ve decided that it was recorded a bit on the “hot” side, meaning that it can sound a bit edgy and overpowering, especially with a system that tends in the same direction.  This album was served up quite nicely using the X-DAC, so I was curious to hear what the X3-DAC might do with it.  The evaluation was carried out using a digital copy (24 bit/ 96 kHz) of my original “demonstration only” LP.  Not surprisingly, the X3-DAC reproduced Hutcherson’s vibes with plenty of energy while never becoming too “ringy-dingy”.  Put a bit differently, the listener should be able to easily hear the complex overtones of the vibraphone, but without the sense that the instrument is becoming overpoweringly screechy and annoying.  If I have a vibraphone recording where this annoyance can rear its head, this is the one.  Nonetheless, the X3 did a fine job of keeping things toned down just the right amount without losing harmonic information and excitement.  This achievement is even more pronounced when I noted that I was listening through the Fritzspeaks Rev 7 speakers, which tend to be a little more open and revealing in the upper registers than my Shahinian Compasses are.


Next I focused in on a cut from the lovely Pablo LP “Oscar Peterson + Harry Edison + Eddie “Cleanhead” Vinson” entitled “Everything Happens to Me” (24 bit/96 kHz digital transfer).  This song is a lovely duet between Joe Pass on guitar and Harry Edison on trumpet.  When I used this tune to evaluate the original X-DAC, I focused in on the dynamic range of the cut, especially in the trumpet part.  In the case of the X3-DAC, what really jumped out at me was the tonal richness of each instrument coupled with the complex interplay between them as the tune progressed.  Harmonic detail was especially obvious along with that wonderful sense of space, or sonic halo, that seems to surround each instrument in a really well made recording.  I could easily hear the trumpet softly enter to the rear left of Pass, and each image remained stable relative to the other regardless of dynamic.


So far so good.  I’m not finding anything that the X3-DAC can’t do better than its elder brother did.  How about moving on to some different music then, shall we?


An album that I often use to test resolution of detail, both harmonic and percussive, is the guitar extravaganza “Passion, Grace, and Fire,” starring John McLaughlin, Al Di Meola, and Paco De Lucia (24 bit/96 kHz digital transcription of the Columbia LP).  I especially enjoy the second cut, “Orient Blues Suite,” as it highlights all three musicians nicely.  With the X3-DAC in my system, instrumental timbre was excellent, as I could easily make out which of the guitarists were playing with gut strings (McLaughlin and De Lucia) versus the harder, twangier sounding steel strung instrument played by Di Meola.  Attack was excellent, as was decay, with each instrument occupying its own space laterally in the soundstage.


Speaking of Al Di Meola, another album that I have been listening to a lot lately is “Elegant Gypsy” (24 bit/96 kHz digital transcription of my demonstration-only copy of the LP).  Here, we find Al in the electric mood, hammering away at some nice rock/fusion tunes.  Via the X3-DAC, there’s plenty of edge to Di Meola’s guitar, but things never get out of hand; the performance is always exciting, yet easily absorbed by the listener.  I also found percussion instruments to be vividly rendered on this recording, from bongos to cymbals and chimes.  I found listening to this album to be an especially pleasant and rewarding experience with partial thanks due to the musicality of the Rein DAC.


I mentioned earlier that the X3-DAC has optional upsampling.  I played with this a bit, switching between native resolution and 192 kHz upsampling.  For a bit of comparison I decided to focus in on the tune “Mediterranean Sundance” from “Elegant Gypsy.”  This is more of a traditional Flamenco piece featuring dueling guitars of sorts, played by Di Meola and Paco De Lucia.  Wonderful sparring indeed, with plenty of fireworks including  the traditional slapping of the guitar body and hooting.  I felt that with the upsampling off, I got a slightly improved sense of attack and natural timbre, while upsampling on seemed to provide a bit more hall ambiance, with more of a sense of echo and decay.  Both presentations were fun, so listeners are invited to choose their poison.


The digital filters, however, were a bit harder for me to sort out.  These, I assume, will be of greatest interest to the most golden eared among us who savor the sound of a butterfly farting in the next county over, as I like to put it.  I spent time rotating through all six options and ultimately found myself gravitating toward filters one and two.  Not exactly sure why, as it was more of a sense I got about sense of realism of the music as much as anything else; one of those things I can’t quite put my finger on.  Again, nice options to have for those who value them, so I offer kudos to Rein Audio for providing them.  If I had to characterize filters one and two (since that’s where I spent most of my time), I’d have to say that one provides a little more immediacy while two gives a slightly rounder and maybe more pleasantly spacious presentation.  Take your pick and enjoy!


Even though most of my listening was via the coaxial S/PDIF input, I’d be remiss if I didn’t mention the usb 2.0 input.  Yep, I tried it as well, using my MacBook Air coupled to the X3-DAC using my trusty Virtue Audio usb cable.  As to be expected of pretty much any well-developed usb implementation these days, the X3-DAC’s was bulletproof.  To say that it is a mere improvement on the original X-DAC would be an understatement indeed.  Said to be asynchronous, this is a full 2.0 implementation, meaning that it can handle 24 bit word lengths with resolutions up to 192 kHz with no problem.  And it sounded good.  In fact, very good.  I cued up a few cuts from “Yes: Live at Montreaux 2003” (24 bit/48 kHz download, HDTracks) and let the music roll.  I was thrilled by the detail, impact, soundstage breadth and depth, and sheer presence as the tunes rolled over me.  It was late at night and I had meant to only listen to a song or two, but I ended up listening to the entire album.  That’s a good sign that the planets are aligned and things are clicking into sync with the system as they should.  Some of the credit could be due to the MacBook Air itself as a transport, as it does use solid state memory, which I have always found to sound superior to a normal spinning drive.  Even so, it was pretty obvious that Rein Audio’s newest usb solution is no slouch.  Though I normally don’t use the usb inputs on my DACs, mainly because of the location of the DACs relative to my computer, I am certainly appreciating how far usb audio has come in the last year or so.




My Antelope Audio Zodiac DAC was the first contender to take on the Rein Audio X3-DAC.  At $1895 (usd) the Zodiac offers similar functionality to the X3-DAC, but without the upsampling or digital filter options.  It does, however, offer a decent on-board headphone amplifier.  My unit is also upgraded with a $900 custom linear power supply from YFS Audio, bringing its grand total cost to $2795.  As a mastering DAC, the Zodiac is exceptionally detailed with a splash of warmth thrown in for good measure.  I find it an excellent all-around DAC and have happily used it as my reference unit for well over a year now.  If anything, I’d say that the Zodiac is a bit less forgiving of poorly recorded or mastered material, as befits its heritage.  Poor recordings through the Zodiac can sound  edgy, harsh, or tinny on occasion, but then again, that’s probably the way the recording was made.  The X3-DAC has a way of glossing over these blemishes, making poor recordings more listenable.  Is the X3-DAC too warm and forgiving?  Well, I guess that’s for each listener to determine... Warmth can be classified as a coloration or as added musicality, depending on where each of us might be coming from.  However, given the price of the stock X3-DAC compared to my modded Zodiac, as well as the ability to go to a less forgiving filter option, there is real value in that there box.


How does the X-DAC stack up against my other DAC, the Sound Devices USBPre2?  Again, the USBPre2 (available for $850 usd in stock form) is really a pro unit with lots of functionality that many audiophiles won’t want or need.  Further, it’s bus powered through the computer via the usb cable.  To alleviate any sonic degradation from the host computer’s dirty usb power, I’ve upgraded the unit with its own YFS linear power supply ($900 usd) as well as with a two headed usb cable, from either Kingrex ($599 usd) or YFS ($475 usd).  At a total cost of around $2300 usd, this option is also considerably more expensive than the  Rein X3-DAC.  During my comparison trials, I found these two DACs to sound almost identical as they shared a detailed presentation along with a small, but healthy dose of warming musicality.  While the USBPre2 offers tons of other functionality that the X3-DAC doesn’t, it lacks the upsampling and filter options. Without the improvements to the USBPre2, it really doesn’t play in the same leagues as the Rein and Zodiac DACs do.  Again, this demonstrates the excellent value offered by the X3-DAC.



So then, does the Rein Audio X3-DAC deliver the goods?  Is the sequel really better than the original?  Need we ask?  Well... Resoundingly YES!  All of the perceived shortcomings of the original X-DAC have been addressed and considerably more user functionality has been built in, all without tampering with the excellent sound quality of the original unit.  At $1280 this DAC should be on any aficionado’s short list for audition, especially if musicality rates high on the list of requirements.  The only disadvantage that I can see is that the only way for someone here in the USA to get one is though Rein Audio’s on-line store, as there appear to be no American distributors or service personnel at this time.  Even so, this little DAC represents excellent value in terms of appearance, user options, and most importantly, its ability to provide great sound.


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