review 'db audio labs tranquility dac

Excellent question / observation regarding the dac's input choice.

db Audio Labs purposely chose not to include the interfaces suggested for very specific technical and MOST importantly, sonic reasons! Basically, for all the interfaces you suggest, some form of circuitry, albeit a chip or discrete componentry, must be included which connects to each of those interfaces and provides an I2S output signal which in turn provided to the dac chip.

So, in essence, each and every interface that you suggest (as well as the USB interface) must output an I2S signal to the dac. Typically, some sort of switching is used to select the respective I2S signal the interface desired. In order to optimize the I2S connectivity to the dac chip, the I2S data signal lines MUST be treated as RF transmission pathways and laid out accordingly. This is seldom if ever done in audiophile consumer products. But, we do it this way with the Tranquility design. In other words, audiophiles desiring numerous interface inputs as is what is typically seen from other dac products, more often than not, prevents optimal RF layout as the I2S signals must traverse the switching necessary thereby adversely affecting the overall sonic capability of those dacs period. So, less inputs makes RF layout manageable leading to better sound.

We also recognize a multiplexer could be used rather than switching. However, multiplexers are not without their own attended problems. As they too impede layout in their own right.

Another thing to consider when adding interfaces, since they are often in the form of some dedicated interface chip and are likely to require some clocking, i.e. an oscillator, for their operation. Those oscillators give rise to the potential of interfering and intermodulating with the oscillator that is in use for the interface selected. Obviously, this like switching, gives RISE to the potential for jitter and usually does, without exception!

dB Audio Labs selected to use USB because there is no correlation between the clock and the audio data. “Jitter”, as properly defined, requires that there is some sort of clock associated with the data. Absent that, there is NO jitter.

SPDIF includes data correlated with a clock thereby allowing for jitter to occur (not as good).

Firewire does not include data correlated with a clock and thereby does not give potential for the rise in jitter nor does USB (much better).

It should appreciated that both Firewire and USB have more than enough bandwidth necessary for the transfer of digital audio data.

However, there is one major distinction between Firewire and USB that is typically overlooked by audiophiles. That is to say, a dac manufacturer who decides to include a Firewire interface on their dac must provide, or be in the business of providing, developing and/or maintaining a Firewire device driver for EACH operating system, (Windows and MAC) for their digital product. And while some boutique manufacturers many be capable of doing such, there is obviously an intended cost to the consumer. Moreover, there exists the potential for a customer to have, for at least some brief period of time between operating system upgrades, for their dac to become inoperable as their current driver could be incompatible as a new version of their operating system is rolled out.

In contrast, USB dacs typically make use of those drivers found in both the Windows and Mac operating systems. USB specifications and standards require this! So, as long as the dac meets the “USB 1.1 / 2.0 standards”, you are golden. And yes, the Tranquility dac meets these standards!

So, rather than spending our time developing and maintaining Firewire drivers, we’ve selected USB connectivity for inclusion in the Tranquility design and put our efforts into developing the balance of necessary circuitry, e.g optimization of transmission paths, power supplies, dac optimizations, I/V stage, analog output stage, parts selection, etc..

We hope that you consider each and every one of these salient points we’ve outlined when selecting your own personal digital to analog converter. We obviously have, as from the foregoing explanations outlined above.

And that is why you only see a single solitary USB input on the Tranquility DAC ;-)

We understand why some posters could think USB connectivity may not be "audiophile approved". That's why we wrote the VERY thorough technical overview (posted earlier in this thread) for everyone to realize how USB connectivity could actually be a phenomenal sounding choice when it is designed and implemented correctly.

But, there are still some detractors that are skeptical, so here's some more food for thought to ponder and consider - It was recently announced "USB DAC Wins Stereophile's Overall Product of the Year!". Hmm, could Stereophile actually be on to something with their most recent assessments and accolades about USB connected DACs too?

And, from the outset, our inherent mission when we created the Tranquility design was - The true measure of any DAC design and its "inherent technology" comes down to HOW IT SOUNDS as compared the actual master tape!

It is our professional opinion that any given type of DAC solution that has the ability to give audiophiles better space rendition, portray the fragile high frequency harmonic overtones more accurately and subsequently sound more real, should "win the day" as the better DAC. This is how we would like to be "measured" by the audiophile community.

Hi Clio09,

The post about Stereophile's top award to a USB dac was mentioned to demonstrate that we are not alone in our findings about USB's potential and mention the fact that other serious audiophiles have also found that some particular USB connected solutions can sound amazing. BTW: Were you aware that the DAC that Stereophile awarded uses Gordon Rankin's technology?

As far as the "proof" you want, we will stick by our personal mantra ; The superiority of ANY dac design should actually be "measured" by it's end SONIC GREATNESS or lack thereof, period. Anything other sort of analysis-methodology, other than how the product actually sounds, is just conjecture and speculation that holds very little merit for a true music lover. If the DAC design sounds as good or even better than some of the best digital in the world, cost no object designs included, then the "proof" has been met.

Per your question about the Music Streamer Pro and m2Tech hiface, we think that both are great "budget" offerings at their respective price points. Comparatively, the Tranquility DAC was NOT designed as a "budget" offering that was just built with "off the shelf parts" or budget connectors or budget power supplies or with budget level output stages.

In comparison, the Tranquility has MANY proprietary circuit refinements that took years of research and development leading to proprietary optimizations incorporated within. We are proud to say we've found optimizations that no one has ever even considered in any DAC, at any price! Top level passive components, capacitors, custom designed power supplies and regulation, custom discrete output stages along with all of the proprietary optimizations to boot! All of this was done in a quest to create a digital solution that offers a whole new level of sonic greatness.

Please note the $500 off introductory sale will be ending at the end of this year, Dec 31st.

Hi Cedunlap,

Sure we can explain the I2S area within the dac and USB's inherent timing/jitter advantages.

In a nutshell, USB interconnectivity does NOT carry timing from the computer, it just carries a "start of frame" signal to let the dac know when to start and buffered packets of music data. So, unlike other connection schemes (SPDIF), you do NOT have jitter induced at the transport or through the USB cable (which is a HUGE improvement comparably...when USB is done correctly). Then you are at the receiver portion of the DAC itself where the timing (and potential jitter may happen). A local oscillator approximate to the receiver provides the timing for the dac process. All of the potential timing issues are related to this area alone (when done right). The choice of the oscillator itself, the way that oscillator is configured, optimized, connected and powered will determine how much jitter is then introduced. With EXTREMELY careful optimization it can really good compared to most other digital solutions, especially SPDIF. There has been so much mis-information about SPDIF being "the best connection" as compared to USB that I think it's about time we really sit down and re-analyze how this came to be. It's just not the case. Then again, there's allot of USB dacs done wrong. Could that be why so many think SPDIF was superior?

So, in essence, jitter is never at zero in the entire solution (as you alluded). It is just down to one singular area (which SPDIF can never even hope to emulate comparably). Once this area is extremely optimized the jitter is managed much better than most other digital solutions.

Of course we like to still point out that the actual proof comes from the sound improvement in any connection scheme. Anything other type of analysis other than an actual true improvement in sound quality is just utter speculation, hype and tech-babble! As compared to other digital solutions, the Tranquility DAC captures and conveys the very elusive harmonic cues much closer to an analog solution. There is a naturalness that most digital struggles to convey particularly in the treble region. This is our "proof" as compared to most other digital solutions. The sound improvement itself.