Review: db System Zardoz Ultimo Transport


Category: Digital

Zardoz: a state of the art WiFi device from db System

Digital audio preamble

For better or for worse, many audiophiles are gravitating towards computer audio. Much of this is driven by the allure of Ipod-like convenience. Rifling through CDs has lost its luster. Modern life is frenetic, and draining, and the 21st century audiophile’s threshold for inconvenience is low. As expected, manufacturers have developed computer based front ends in which an entire music library can accessed and perused instantaneously, with purported sound quality superior to many CD players. In parallel with this development, new high resolution formats are popping up like mushrooms, adding yet another layer of temptation for the weary audiophile. Currently, a mosh pit of devices exist, framed by bold claims and subsequent debates and tribalism on audio threads regarding what is technologically relevant. I myself was recently involved in a lengthy thread on the importance of jitter. A lot was said. Little was answered.

The digital realm, much like the computer industry, is very fluid. What is hot today may be disregarded tomorrow. Furthermore, the theoretical basis for digital performance is surprisingly fuzzy and ill defined. We can only postulate why things sound they way they do. To me, the central issue is this: what digital technology relaxes the soul? To many, the road to relaxation is built upon recreation of an “analog” sound. From a literary standpoint, the term analog is difficult to describe. For me, it evokes exhalation and the calm that follows. Mentally and emotionally, it takes me back to a time when things were indeed relaxed, such as college summers, with all the bohemian meandering. When I listen to music, this is where I want to be. Bad digital playback fails to produce this experience. What are the attributes of bad digital? Sharp, brittle, edgy notes, like thousands of little razor blades perforating the eardrum, making it bleed. Your ears fatigue. Your listening sessions shorten. Yes, digital is dynamic and possesses a low noise floor, but much of it is an assault on the senses. In a recent article in the Wall Street journal by Terry Teachout titled “The Mystery of Music,” there is a quote attributed to the late Jazz great Eddie Condon regarding empirical measures of musical quality that I think is very poignant: "As it enters the ear, does it come in like broken glass or does it come in like honey?" That is how we should measure digital playback.

The Search

I was not systematic in sifting through and researching options for computer audio, nor have I done explicit head to head comparisons. I sold my Granite Audio 657 CDP prior to receiving the Zardoz, so any direct comparison would be a derivative of sonic memory only. My goal in this review is to describe what I am “hearing” in light of the prelude about analog sound. The Granite CDP was a fantastic piece (one of the best honestly), but I grew increasingly tired of getting up and down to change CDs. When used without a pre-amp as I did, the 657 was very dynamic and live sounding with a huge soundstage, great bass, detail, etc. However, a subtle fatigue would creep in, especially with certain pieces of music (this may have been a system issue, but that is a moot point now). During this time, I had a chance to fiddle with a Sonos (wireless device) at a friend’s house and was hooked. The evil seed of computer audio had been planted. Rifling through your entire music collection with a light finger tap on a touch screen was too good for words. The only problem was the sound: it was just brutal. An unadulterated Squeezebox or Sonos is just plain rude even on an average system. You need a DAC, power supply mods, etc to make them palatable IMO.

In my extensive reading and research, there appeared to be many good options. Empirical Audio Pacecars, Memory Player, cMP (homemade computer-based memory player) Berkley DAC fronted by a computer with a trick sound card, heavily modded Squeezeboxes, heavily modded Sonos, etc. Many of these options were either expensive or two box solutions. I wanted a simple, one-box solution that did not require a DAC, extra cabling, and was also extracted from the computer itself and its inherent flaws. I did not have the time or inclination to dick around with modding a computer (or paying someone else 5-10K to do so). I wanted a plug and play option that was mucho analog sounding, convenient, and user friendly. Enter the Zardoz….

My discovery of the Z was serendipitous. A French audiophile who goes by the moniker Juanintox on Audiogon posted a picture of his rig within the context of a speaker thread. Everyone asked what this one particular box was, and he proceeded to wax poetic about this “Zardoz.” He was a vinyl guy, and this was the best piece of digital he had heard. It replaced an Audio Aero Capital 24/192. He and Dan, the lead engineer and owner of db System, had apparently performed multiple blinded shootouts between the Zardoz and many alternative digital rigs (dcs, Audio Aero 24/192 mkII, Wadia 860X, PC >> Empirical Audio Offramp turbo >> modded Pass Labs D1, modded Squeezeboxes, etc). The Z won them all. I was intrigued and once my Granite sold, I decided to take the plunge. Please note that Dan’s primary vocation, in addition to being a French engineer with a background in computers, has been as a designer of hi end tube gear at db Sytem in France. He is a true analog nut, and tubes and vinyl are his sonic reference. That was important information. Right or wrong, I have an implicit trust of analog guys and their sonic bias. That is my bias despite being a Gen X CD dude.


Technical data

Before launching into technical issues, one important question should be answered: why wireless (WiFi)? Many audiophiles perceive wireless music streaming as a low or midfi technology. This is incorrect. Wireless transmission of data possesses an inherent superiority for several reasons. One, you are quarantined from potential garbage or noise from the computer itself in the form of high frequency radiation. According to some, this can have an audible influence (please see the LessLoss site for further details on this subject: http://www.lessloss.com/page.html?id=45). Second, potential sources of jitter are minimized. There are multiple sources of jitter in any given system, including the power supply, the computer, inputs, DAC chips, cables, etc. Steven Nugent, founder of Empirical Audio and former lead chip designer for Intel, recently published an article on the subject of jitter in Enjoy the Music: http://www.enjoythemusic.com/Magazine/manufacture/0509/. He delineated various sources of jitter, and in particular, he described the inherent benefits of wireless audio:

“Networked audio (Ethernet), both wired and Wi-Fi is a unique case. Because the data is transmitted in packets with flow-control and re-try for errors with buffering at the end-point device, it is not as much of a real-time transfer as USB, S/PDIF or FireWire. Networking also avoids the use of the audio stack of the computer audio system since it treats all data essentially the same. Because of the packet-transfer protocol of Ethernet and data buffering at the end-point, the jitter of the clock in the computer is a non-issue. The only clock that is important is the one in the end-point device. Examples of end-point devices are: Squeezebox, Duet and Sonos. This would seem to be the ideal situation, which it certainly is. The only problem that can occur is overloading the network with traffic or Wi-Fi interference, which may cause occasional dropouts. The problem for audiophiles is that the majority of these devices were designed with high-volume manufacturing and low-cost as requirements, with performance taking a lower priority. As a result, the jitter from these devices is higher than it could be. It should be the lowest of all the audio source devices available.”

The Zardoz platform is built around Apple’s Airport Express wireless receiver. The prototype of this device debuted on July 21, 1999 at the Macworld Expo in New York City. Since then, it has gone through many permutations. The AirPort Express is essentially a simplified version of the AirPort Extreme base station. The main processor in the AirPort Express (802.11g version) is a Broadcom BCM4712KFB wireless networking chipset. The current 802.11n version, which my Z is derived from, employs an updated version (MB321LL/A) that allows transmission in both the 2.4GHz and 5GHz bands. Audio is processed by a Texas Instruments Burr-Brown PCM2705 16-bit digital-to-analog converter. Dan, the lead engineer at dbSytems, has modded the Airport express in a number of innovative (and proprietary) ways. Due to the small size of this artisan company, I will be lean on the specifics for the sake of intellectual property protection.

The Zardoz is not simply an Airtunes receiver with a new power supply and a few new caps as is often the case for other modded WiFi devices. It has been gutted and redesigned on multiple levels. First, he has decoupled the Burr-Brown DAC from the signal path and rerouted the data to a proprietary, external master clock built around a chip manufactured by a semiconductor company not normally seen in hi end audio. Jitter levels are vanishingly low (< 12 ps peak to peak). Second, the clock also has its own power supply, designed by Dan. Third, Dan has tricked out the main power supply using a proprietary double regulated, filtration process with ultra fast, soft recovery rectifiers. This power supply possesses close to 200,000 uF of filtering capacity. This is important since undulation in power supply voltages contributes to jitter more than almost any other variable. Again, according to Nugent:

“Power "noise" as it is referred to is probably one of the largest contributors to jitter.”

Fourth, the output stage has also been modded. Silver wiring is used throughout, along with upgraded caps. The digital outputs are rigged with Lundhal transformers, and options include SPDIF, AES/EBU, and USB if so desired. Balanced analog output is an option using passive transformers with amorphous cores from Lundahl in Sweden.

In terms of construction, the fit and finish of the Zardoz is elegant and top notch. Aesthetically, the Zardoz is very attractive. Dan works with a cabinet maker who constructs beautiful boxes out of Teak wood. Dan believes that Teak possesses certain attributes that positively effects sound. Whether that is true or not escapes me. All I know is that the WAF is very high. Case closed.

The System

Speakers: Intuitive Design Gamma Summits
Amplifiers: Intuitive Design Coordinate Monoblocks (housed in ID granite stands)
Pre-amplifier: Tube Research Labs Dude
Source: db System Zardoz (WiFi receiver) fed by an Apple MAC Mini + Apple Time Capsule router
Cabling: Intuitive Design speaker wire, ICs, and power cords throughout
Isolation devices: Stillpoints on speakers and stands; Sistrum stands for Dude and Zardoz
Remote: Apple Iphone 3G

Listening Vignettes:

When it comes to listening sessions and formal analysis, I am not as disciplined as some. I rarely perform a complete vivisection of a piece of gear and its attributes. I think it is more revealing to describe what it does within the context of a specific piece of music, or even within just one part of that music. To me, these little audio vignettes speak the most clearly and give the reader more potential revelation, a light unto your audio feet.

1. Cowboy Junkies, Trinity Sessions: this was actually one of the first albums I played after getting the Z. Sonically, this album is spooky. It was recorded in an old church and has a cavernous, sonic ambience imparted by the size of the space. I have “listened” to this album a lot in the past. Now, I was tuning into things I had missed before. In “Mining For Gold,” the song begins with the sound of coal cars in the background or periphery of the stage. I could hear each car clicking by with cumulative echoes creating a weird, ghostly hum. This “detail” was new. Margo Timmins voice is very clear and well defined with each inhalation articulated. The echo of her voice is also beautifully defined as it travels outwards to the perimeter of the church much like waves created by a stone hitting the water. The echo delineated the space, and this recreation of the recording venue was stunning. This simple experience opened my eyes and transformed my listening experience of this album. Every note and instrument expanded outwards in the same fashion. Furthermore, the Z’s presentation possessed see-through clarity within the context of a relaxed sound. Yeow.

2. Eva Cassidy, Songbird: a favorite album of mine. She was an exquisitely gifted singer who succumbed to metastatic melanoma at the tender age of 33. Her voice knew no bounds and she was free ranging musically, singing everything from gospel to jazz and blues and inventive covers (Police, Fields of Gold for example). Again, the Z stripped away the digital fizz so I could zero in on individual instruments and the actual space they space they inhabit. On the song, “Songbird,” Eva’s voice is captured with all its mellifluous texture and vibrancy. For the first time, I heard the backup singer directly behind Eva, singing in her shadow, with a magnificent and powerful voice in her own right. Please note that this album is not well recorded. It is bright and forward, particularly when she nails her high notes. With my previous front end, it was hard to listen to for long periods of time. Not so anymore. That is an achievement…being able to listen to less than stellar CDs without losing necessary detail.

3. Steve Davis, Quality of Silence: this album is an extremely well recorded (DSD/SACD hybrid) piece of music. It is what I would call ambient or atmospheric jazz. The philosophical gist of the music is that less is more and what matters inhabits the silence between the notes. The sparseness of the format allows your brain to track individual instruments and the veracity their portrayal. “Yesterdays,” the second track features Steve Davis tinkering in the background on the drums. Gentle, single strikes on the cymbals and their idiosyncratic resonance are captured with great depth, energy, and a sense of the recording studio space along with a perfect timbre. I feel like I am right in the studio with a cup of coffee in hand.
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4. Eric Clapton, MTV Unplugged: this is a well recorded live album. On the song “Malted Milk,” you can hear Clapton tapping his foot on the stage. I had noticed this artifact before, but now, I could hear the initial tap of his shoe on the wood followed by the dull thud that was propagated with an echo that seems to travel in a longitudinal fashion towards the listener and away to the back of the stage. Clapton’s voice echoes upwards, like a plume of smoke. Again, this was new detail, but the Zardoz did not present it in a fatiguing or irritating way. It was eminently musical. Also, the pluck of his guitar was incisive, dynamic and woody sounding. A perfectly portrayed acoustic illusion, almost (almost) as good as being there. This is an important feat for this “live, small venue” music lover.

In summary, the Zardoz scales a peak that is very difficult in digital audio: clear and realistic rendering of detail, dynamics, openness, and an accurate recreation of space in the context of a mellow, relaxed, analog presentation. Crappy CDs are tamed (to a degree). Good CDs sound off the map. You can listen for hours and hours without fatigue. To top it off, this can all be done with an eminently pragmatic device that allows you to stream your 4000 CD collection and thousands of internet radio stations at the brush of a finger. What more would you want? The Zardoz is indeed audio honey for the audiophile’s ears.

p.s. Please feel free to email me with questions. If they are of a more technical nature, I will forward you onto you onto Dan (contact data below*) whom you can Skype or email anytime. The website is in French, but Dan speaks excellent English. He makes himself readily available. If you are in or around Charlotte, NC, feel free to swing by for an audition. Ciao.

Andrew J.L. Gear

*db System
c/o Dan Bellity
5 ave Jean XXIII - 06130 Grasse - France
Tel : (33) - 04 93 42 53 47
Fax : (33) - 04 26 00 72 74- 04 26 00 72 74
db-system@wanadoo.fr



Associated gear
Speakers: Intuitive Design Gamma Summits
Amplifiers: Intuitive Design Coordinate Monoblocks (housed in ID granite stands)
Pre-amplifier: Tube Research Labs Dude
Source: db System Zardoz (WiFi receiver) fed by an Apple MAC Mini + Apple Time Capsule external HD/router
Cabling: Intuitive Design speaker wire, ICs, and power cords throughout
Isolation devices: Stillpoints on speakers and stands; Sistrum stands for Dude and Zardoz
Remote: Apple Iphone 3G
agear
I forwarded Dan your concerns and here is his reply. He had technical difficulties trying to post to this thread, so here is his reply:

"Hi Andrew,

Sorry to all of you whom have not received answers to your emails. For a time, I had a very aggressive, anti-Spam filter and thus many emails were blacklisted.
Now the problem is solved. (I read all my emails including Spam:-)

Another good option is Skype. Then, we can speak face to face.

To answer the question of resolution of the original AE: it is 24 bits 48kHz maximum. It was probably limited by Apple to reduce the quantification noise generated by upsampling. The chip that I have used in the Zardoz is made by Marvel and is 96Hz capatible and even higher.

Please feel free to Skype or email me with further questions.
Kindest regards to all of you.
Dan Bellity"
From what I have read there are a number of ways that 16/44 is implemented in digital players. One is without upsampling/oversampling and without filtering. These are commonly referred to as the NOS DACs, etc. which Audio Note and Sakura Systems (47 Labs) made famous and others followed suit on. One of the more popular chips used in NOS designs was the TDA-1543 made by Phillips. Funny, just this weekend I was listening to my TRL modified Audio Mirror DAC that uses this chip (8 in parallel) with no upsampling/oversampling or filtering and was re-acquainted again with the extremely smooth and analog sound. In some ways I enjoyed it better than my current digital front end. The knock, for right or wrong, on NOS designs is that they are limited in their ability to handle complex music.

Another method is using a non-upsampling/oversampling approach with filtering. The AMR CD-77 player offers this with the Phillips TDA-1541 chip and allows the user to select from no digital or analog filtering to an option that has no digital filtering but applies analog filtering. I can say from experience in listening to this player that these options have an effect on the sound, I preferred the option with no filtering at all. This CDP also allows one to apply different sampling rates. There are 2x and 4x oversampling options and 96 and 192Hz upsampling options. Again, each has an effect on the sound. My favorite was 16/44.1 with 4x oversampling. For those interested there is a good discussion by Lynn Olson on NOS designs and digital chips here:

http://www.clarisonus.com/blog/?p=80

That being said the new hi-rez formats used in digital download sites require that computer audio designers begin thinking more and more about supporting 24/96. It appears that Zardoz has gone to 24/96 and may be going to 24/192 in the future so they have addressed this. If I were going to computer audio I wouldn't buy a solution that could not at least handle 24/96.

Andrew,

Its my contention that some of the discussion surrounding 24/96 and 24/192 are perhaps self fulfilling. I have heard 1 bit DAC's sound like analog and multi-bits sound more analytical. And I have "ripped" copies on redbook from my small vinyl collection that sound superior in many ways. so there is no one solution. This makes the voyage fun!

Dan-

Thanks so much for responding here. I am glad Andrew was able to shed some light on the Zardoz device. I have respect for anything that sound superior relative to devices that cost 5x the price. The Lundahl transformers are the most musical of its type. I enjoyed them in my Cd player a few years back. A wise choice to say the least.

I appreciate if you can comment on what your future plans are for making this device more accessible in the US for auditioning. I would imagine that Zardoz can become a household name.

Great job Andrew.

Thanks
Thanks for the data Tony. I have perused a few discussions on digital processing formats and always came away with the impression that NOS produced a more "analog" sound. For a while, I was looking into both Wavelength and Ultrafi DACs using that format. At the end of the day, I guess its a matter of implementation rather than processing format???

Luis, much of the banter is self-fulfilling. Others have born witness to your observations that increasing bit rate resolution and sampling rates does not always translate into a more analog presentation. I tried to insinuate that in the review and Juanitox was more blunt about it. I know some of this by experience as well. My Granite Audio 657 CDP used a DAC chip with 20bit/96KHz DAC chip. Don Hogland told me he chose this particular chip over other 24 bit versions since it sounded more "musical." People gave him crap about it, but I am afraid I agree. The 657 was an incredibly good CDP and bettered a lot of players with fancier 21st century chips. I have heard a similar testimony from Steve Nugent at Empirical in that certain chips (even with a similar bit rate) sound better than others. There is obviously more to this story.
I have to admit that the article by Lynn Olson opened my eyes to some things in the digital realm that I had not thought about previously. Especially the fact that some chips truncate the bits. However, having listened to the TDA series chips (which for some reason Lynn bashes) and the 20 bit chips, I'd have to say that 20 bits (and even some 18 bit chips) provide a nice trade off (BTW - I used to own the Monarchy M24 DAC that Lynn Olson raves about and he is spot on in his assessment of this piece). They offer additional detail, but without seemingly coming across as too analytical. From a 24 bit perspective it is interesting how many CDPs/DACs that have been said to have a musical and analog type sound use the PCM-1704-K.

I don't know why more manufacturers don't offer the option to select different sampling rates or filters. Given the option I think my preference would be 24/88.2 or 24/176.4. The even sampling rates seem to work out better than then odd ones for the most part, although due to marketing reasons we consumers are usually stuck with the odd ones.

I have always been fascinated by Don Hogland's amp designs (I actually use one of his burn in CDs to tune my system occasionally). However, I was unaware of the chip used in the 657 and I may have to look into this a bit more. Don is not that far away from me and I'll be heading to Phoenix in a few weeks for a weekend so maybe he'd be willing to entertain a visit from me.

I have to say that I am interested in learning more about the MARVEL chip used in the Zardoz and how it is implemented. These questions were the premise of my original emails to Dan that were never addressed. Maybe he could weigh in here on the topic.