Six DAC Comparison

Thanks, Mitch -- I’ll look forward to reading the next installment, for sure. Interestingly enough, we sell both Merason and Bricasti at the shop where I work (Alma Music + Audio in Sterling, VA), and a colleague from another shop whose opinion I respect just recently suggested the LTA Aero as a potential giant killer. I’ve been considering a Bricasti M1 Series II, but this thread really has me approaching the process with a far more open mind. Unfortunately, the Aero lacks the AES input that I’d like to use from my [CEC TL5] transport to whatever DAC I end up with. I’ve got tubes covered with my Prima Luna Floyd Integrated (rolled with 60s [signal] & 70s RCAs), so my desire is to find something that will complement the existing configuration. Making things (far) more interesting, I recently picked up a pair of YG Carmel 3s, which are musical & revealing as all get out; particularly paired with my trusty ’ol REL S/812. I will say that I really like the sound of the Bricasti, but we’ve got ’em paired with various darTZeel bits, so the influence of the far more high-end components (compared to what I’ve got at home) is undeniable.

@zmann007 - My thoughts on the $4K LTA Aero should be posted by tomorrow, and the $2K Benchmark write-up is also almost done and will go up shortly after.  I have started listening more seriously to the Merason, which will follow, then the SMc Audio DAC-2 and finally the Mojo Mystique X SE NCZ.

Benjamin’s Mystique Y would be a good one to also look at for $4K, but I haven’t heard it.  Here is a link to a review.

I'd just like to say that this is brilliant, and greatly appreciated... particularly from the perspective of someone who's in the midst of searching for an extremely high quality DAC that won't break the bank. Products in the Mojo Audio line-up hadn't been in the running before, but they certainly are now.

The “Z” in X SE NCZ means the X SE unit I own already has the Z-chips, as well as nano-crystalline chokes (“NC”) making it essentially Benjamin’s current “flagship” DAC.

I did talk with Benjamin some time ago about moving the Z-chips from my EVO Pro to a non-Z, X SE but he said there was more involved than simply swapping the chips so I didn’t go forward with that.

@mitch2 I don't think you have to worry about people thinking you are biased.  You have been very transparent about your comparison.  I am interested because I have an smc amp and may get a preamp from smc so our systems might be very similar.  Have you ever thought about swapping the chips in your DACs and putting the z-chips in the new X SE NCZ?

Benjamin brings up a very important point in that with any of this stuff, the subjective opinions of reviewers, manufacturers, equipment owners, and others are predicated by the personal experiences and preferences of the individuals providing their point of view, as well as their partnering equipment and music choices.  I can only refer to the "Disclaimer" portion of my post from 9/14 at 10:38pm, where I said, in part, 

"my subjective observations will be biased" and 

"The write-ups I will post are not intended to be interpreted as an authoritative “last-word”"

I do not expect everyone else to view things the way I view them.  However, keep in mind that I have twice owned the Mystique X SE DAC at the same time as I owned the Mystique EVO Pro DAC, and I currently own the top-of-the-line, flagship Mystique X SE NCZ version as well as the EVO Pro (with Z-chips) that was the subject of my write-up posted on 9/14.

I am currently focused on the LTA Aero but, as I stated in this thread previously:

I will save the Mojo Audio Mystique X SE NCZ until last and provide a comparison between the two Mojo Audio DACs.  My initial impression between those two DACs favored the EVO Pro but because of the many positive reviews of the X SE, my discussions with Benjamin, and my purchase of the NCZ version of the X SE, I will revisit my comparison between the two Mojo Audio DACs to find out if I reach the same conclusion.

@ brbrock

Yes.

I'm working on a Mystique Z that will be built around the PCM58 DAC chip and will have an external power supply. 

The power supply upgrades will be plug-and-play so customers won't have to send their DAC in to us for upgrades. 

The entry-level power supply will have Hammond chokes (like our Mystique v3) and the top-of-the-line power supply will be dual-mono with LCLC dual stage nano crystal core chokes and will have no electrolytic capacitors.

We're hoping we can sell the entry-level model for as low as $7,500 and we're expecting the top-of-the-line model will have to sell for over $15,000.

But don't expect to see anything sooner than the end of 2025.

We just purchased some new software and testing equipment that will be used in the R&D which I would expect to be a rather lengthy process.  

@fuzzbutt17 Benjamin can you tell us if you have anything in the works for upcoming models?

Benjamin from Mojo Audio again.

I very much appreciate Mitch as a customer as well as Mitch's efforts in this incredibly detailed review.

That being said, I wanted to offer a bit different perspective.

When our Mystique X just was originally released we sent them out to dozens of our customers who owned Mystique EVO B4Bs and EVO Pros. 

After comparing the two DACs side-by-side in their own systems all but one of those people preferred the sound of our new Mystique X and paid thousands of dollars to upgrade their EVOs to our new X.

And a few of those people were professional reviewers who owned our EVO Pro.

You may want to check out the many raving reviews and awards our Mystique X received on our website. 

Everyone hears things a bit differently and every system has a bit different synergy with certain components. 

But I think it should be taken into account that Mitch is one of only two of our customers out of the several dozen who compared our Mystique EVO and our Mystique X side-by-side in their own systems who preferred the sound of our EVO.

As for my personal opinion... 

We get a few Mystique EVOs sent in each year for upgrades and I get a chance to hear them on our test bench. To my ear they sound a bit slower, softer, and a bit vague when compared to our Mystique X. A large part of this has to do with our Mystique X having a notably lower noise floor than our EVO. 

Technically speaking the reason for this is that our Mystique EVO has a series of power and signal cables that run beneath the digital and analog circuit boards as well as wires between the circuit boards and the connectors on the rear panel.

In addition, we upgraded a few parts in the power supplies, such as going from the fast recovery diodes used in our Mystique v3 and EVO to zero-recovery ultra-fast SiC Silcon Carbide Schottky diodes used in our newer X and Y series.

We also went from using three off-the-shelf unshielded PCB mounted power transformers that were used in our Mystique v3 and EVO to a 100% custom multi-voltage fully shielded Toroidal power transformer mounted on a Sorbothane pad that is both electrically and mechanically isolated from all circuit boards in our newer Mystique X and Y DACs.  

And unlike our Mystique v3 and EVO DACs all of the input and output connectors in our newer X and Y series mount directly to the circuit boards without any wires. 

The result is a notably lower noise floor which translates to more transparency between notes, a more open soundstage, a darker background, more micro-details, and more micro-dynamics. 

Which explains why literally dozens of our customers upgraded their Mystique EVO to our newer Mystique X.

Of course being the designer, I am obviously prejudice :^P

@mitch2 - Great review, Mitch. I’m very intrigued by the Mojo Audio line of DACs now. It sounds they simply bring joy to the experience of listening to music. In my book, that’s mission number one. Will be curious to hear your thoughts on the LTA DAC next. Lots of people seem pretty excited by it, so will look forward to hearing what you think its strengths are. 

@brbrock - pretty sure the LTA Aero uses chokes but not the big Lundahl chokes used by Mojo Audio.  I will look into it.  I suggest reading the links I posted that have direct comments from Benjamin Zwickel if you haven’t already.

@mitch2 Thank you for the reveiw.  I'm in the market for a DAC and  I am very interested in the Mojo DAC's.  Benjamin at Mojo talks about his DACs being different because of the chokes.  Does any of the other DAC;s have chokes?  I don't think I have ever seen or heard of another SS DAC with chokes. 

Mojo Audio Mystique EVO Pro

 

Applicable Articles and Published Reviews

Dagogo – Benjamin Zwickel on the Mojo Audio Mystique v3

Enjoy the Music – Jeremy Kipnis’ review of the Mojo Audio Mystique v3

Audiophilia - Karl Sigman’s review of the Mojo Audio Mystique EVO Pro

Enjoy the Music – Dr. Matt Clott’s review of the Mojo Audio Mystique EVO Pro

 

Observations

The Mojo Audio Mystique EVO line represents the enhanced evolution of Mojo Audio’s full-width chassis DAC design that began with their Mystique v3 (reviewed by Jeremy Kipnis at Enjoy the Music). The Mystique v3 DAC is also the first Mojo Audio DAC to use the 20-bit AD1862 R-2R chip (previous Mojo Audio designs used the 18-bit AD1865 chip) and the first to use five choke input power supplies. If you are interested in Mojo Audio’s Mystique DACs, please read the Kipnis review as well as the Dagogo article linked above as they provide historical background information about the Mojo Audio DAC designs. In awarding the Mystique v3 a Blue Note Award - 2018, Enjoy the Music editor, Steven Rochlin, said this:

"What I heard through the Mystique v3 was what only some of the very best DACs in history have been able to achieve: a rare and breathtakingly seamless emotional connection to the music and sounds being produced from my wide array of review speakers, on hand. The qualities this DAC lets through are the sort of experience one can expect when attending a live concert and sitting in an ideal spot. If you close your eyes and listen carefully, you can resolve all sorts of details that most people never bother to think about, but that they hear in the background, anyway. So often, these subtle inner details are crushed or distorted much the way different lenses change the viewer’s perspective in photography."

"But when listening to a well constructed audiophile recording on a tuned music system, and occupying the center position in one’s listening space, the distortion that generally affects most digital music reproduction is almost completely absent with the Mystique v3. This rare DAC repeatedly allowed me to feel the sound in a tactile, visceral, and musically meaningful way, that allowed my music to both come alive and remind me of the very best analog sources I have had the pleasure of hearing and working with – right off the 1st generation masters."

"Not surprisingly, I was stunned to hear inner instrumental details from recording after recording that simply resolved hidden elements like never before. Through the Mystique v3, the shear clarity at the loudest and softest ends of the dynamic spectrum, in combination with a palpable, detailed portrayal of the acoustic and instrumental space around and between the musicians, made for a truly scintillating listening experience that gave me goosebumps. Now and again, I was able to also hear a much more precise, characterful recreation of the various room acoustics surrounding the microphone(s). Through the Mystique v3, the degree to which one can "see" or rather "hear" the size and shape of the many different room acoustics, and even height being clearly heard, are all revealed much more easily than with just about any other DAC I’ve played around with. The rather surprising level of timbral detail, dynamic honesty, and harmonic accuracy revealed by the Mojo Audio Mystique v3 DAC is simply and utterly amazing, especially with recordings I have heard repeatedly on some of the best DACs in the world. If the point of our hobby is, indeed, to e, I can think of no finer way than to call up Mojo Audio and order up a Mystique v3 DAC to enjoy digital audio at it’s finest... each and everyday!"

I shared the link to Kipnis’ review, and Rochlin’s comments above, to illustrate the effect that the sound of the v3 DAC had on those experienced audio equipment reviewers and to show why, after reading the review, I was compelled to purchase the second-hand v3 that eventually replaced Metrum Acoustic’s Pavane and Adagio in my system. When I found out Benjamin Zwickel had introduced the Mystique EVO line as an upgrade to the v3, I purchased a new Mystique EVO B4B 21 DAC directly from Benjamin. The B4B 21 was the middle child in the EVO line that included the basic, B4B, and Pro models. Like the v3, the EVO B4B 21 ticked pretty much every audio box for me and provided the best digital sound I had ever heard in my system. Within a year or so, I saw a for-sale listing for a Mojo Audio EVO Pro model, and I purchased that, which is the subject of this write-up.

The improvements in moving from the v3 to the EVO B4B, and finally to the EVO Pro were incremental but certainly noticeable. IMO, the house sound for all of those DACs includes full and deep bass, underpinning a tonally rich midrange, and extending to smooth and sweet-sounding high frequencies. These enjoyable sonic attributes collaborate rather than compete with each other, resulting in an organic, natural-sounding presentation that some might describe as reminiscent of vinyl playback in that it doesn’t sound like the digital reproduction that I had become used to before owning the v3.

The EVO Pro DAC somehow accomplishes the sonic signature described above without any perceived loss of detail or drive. The detail is present, the bass can be felt, and the midrange sounds so natural that vocals are a pleasure to listen to. The main thing I like with the EVO Pro is that it all works together to create a coherent and believable sonic presentation. The EVO Pro avoids sounding unnatural like some DACs that are detailed to the point of sounding etched, or that make it seem as if vocalists have moved out into the room, or that present overly damped/tight bass with little to no decay. I also hear no unnatural or irritating roughness, dryness, or congestion, regardless of the source material or how busy the music gets and, as a result, the EVO Pro could be considered somewhat forgiving of poorly recorded source material. All of this leads to engaging and enjoyable listening sessions without listener fatigue, at least in my room.

When listening to Birds through the Mystique EVO Pro, the opening bass line just jumps out at you big and full, with the sense of fingers on strings. The drums and different percussion instruments are distinct. I can easily hear the differences in tone and inflections between Dominique Fils-Aime’s lead vocals and her back-up singers. Not only is the detail present but the instruments carry weight and the singing is tonally rich. It is similar with The Girl from Ipanema, the instruments sound real and are perfectly proportioned to back up the wonderful singing by Joao Gilberto and Astrud Gilberto. Through the EVO Pro, the music is so relaxed I have the feeling I am sitting under a palm tree at an outdoor café.

Freddie Freeloader was perfectly balanced between Miles’ horn, the percussion, and piano. The attack and sustain of the piano keys were realistic and engaging. Sound staging was rock solid with each player perfectly positioned for a sense of realism.

I just saw the Tedeschi Trucks Band a few weeks ago and listening to the live version of Angel from Montgomery took me right back to the concert. Through the EVO Pro, Susan’s unique tone sounded just right.

Even the rock selections on my list like Thorazine Shuffle, Fell on Black Days, and Staind’s Outside were big and loud enough to be believable. I sensed no breakup or strain through my system when rocking out to those songs at a pretty loud level.

You might ask, so how much of this is related to the EVO Pro and how much to the rest of the system itself and I would have to say, I don’t fully know the answer to that. Some thoughts would be that my 650wpc SMc monoblocks can put out serious juice and do it in a controlled and musical manner. In addition, the Aerial LR5s like lots of current and can get really loud without strain as discussed in the review by Michael Fremer. So, the system itself might have something to do with why all six of these DACs sound pretty good to me. However, I do hear differences between the six DACs and not all of them do the things I discussed above to the same level, or in the same manner.

Does the EVO Pro do anything wrong? Here is where I come up a little short. I have owned a few DACs at or around the same price range but nothing in the $15-20K range, with the Tambaqui coming closest, and the Tambaqui is not a good comparison because the sound of those two DACs are quite different. What I heard from the Tambaqui was all about musical precision, which didn’t exactly correlate to the rich, full, natural sound I hear from the Mojo Audio DACs. I have said a couple of times that to my ears, the Tambaqui sounded “perfect” but not necessarily in a manner that engaged me the way the Mojo Audio DACs engage me. I can imagine some of you readers thinking, “what an idiot to sell a Tambaqui for this older technology R2R DAC!” Oh well, this is my subjective comparison, based on my musical preferences, and it is what it is.

I can refer you to the linked Dr. Matt Clott review of the Mystique EVO Pro, where he compares the EVO Pro to his $40K Davinci 2 and $19K Pilium Audio Elektra and said, “During my comparisons, and to Benjamin’s enormous credit, I never felt the Mystique EVO B4B to be massively outclassed.”

Therefore, to wrap up, in my world and considering the general price range, I perceive no significant sonic shortcomings to the Mojo Audio Mystique EVO Pro, although some might own DACs that offer a bit more detail, a more expansive perceived sound stage, and/or a touch more refinement (like I hear from the Merason DAC1 MkII). Some might not care for the appearance of the very plain black box (that weighs about 30 pounds), or the absence of knobs, displays, or functions. Also, the absence of an I2S input, and/or the ability to decode DSD or MQA may be a deal breaker for some. However, for others, the Mojo Audio house sound, and the Mystique EVO Pro specifically, could be just the thing that elevates their digital source to a higher musical level.

To quote Karl Sigman from his linked review:

“how many (DACs) can take the basic ingredients of fine imaging, extraordinary transparency, textures, spatial cues and impressive timbral accuracy and combine them in a 3D soundstage in an uncanny way into something that sounds so beautiful, natural sounding, musical and addictive as to demand that one say (often attributed to Aristotle), “The whole is larger than the sum of its parts”? Very, very few. The Mojo Audio Mystique EVO Digital-to-Analog Converter is certainly one of them.”

FWIW, my observations discussed above were based on running the EVO Pro through its S/PDIF coaxial input and balanced outputs. My system is as described earlier in this thread, with the pertinent digital front-end consisting of a SGC sonicTransporter i9 (Gen4), fiber to a Sonore Signature Rendu SE, USB to a Singxer SU-6 DDC, and then the coax output to the EVO Pro.

Preamble

My next post will consist of my observations of the Mojo Audio Mystique EVO Pro DAC.  This will be the longest write-up of the DACs being compared since I have owned this one the longest and I am very comfortable and pleased with the sound of the EVO Pro DAC.  The EVO Pro will be my baseline, or reference, for the following DAC comparison write-ups. 

In my write-ups for the individual DACs, I plan to link professional on-line reviews related to the subject DAC.  To get the most out of my comparison write-ups, I suggest reading the linked reviews, because they will contain technical, operational, and aesthetic information about the subject DACs that I will not repeat in my write-ups, and because I may refer to comments contained in some of the reviews.   In addition, I agree in general with the observations and conclusions reported in the published reviews for these DACs.   However, in some cases you need to read between the lines, and certain reviewers either have bias for or against a certain type of sound, or exaggerate certain aspects of the subject DAC but, overall, I believe the reviewers mostly nail the essence of each DAC.  

After the EVO Pro, I plan to post a write-up on the Linear Tube Audio Aero DAC, because there seems to be the most interest in that DAC and because I am under a time line for that one.  I will save the Mojo Audio Mystique X SE NCZ until last and provide a comparison between the two Mojo Audio DACs.  My initial impression between those two DACs favored the EVO Pro but because of the many positive reviews of the X SE, my discussions with Benjamin, and my purchase of the NCZ version of the X SE, I will revisit my comparison between the two Mojo Audio DACs to find out if I reach the same conclusion.

Disclaimer

Keep in mind that my subjective observations will be biased by my personal auditory preferences, my home system (virtual system posted here), my music selections, and my methodology (or lack of).  Also remember, this is NOT a play-off or “best DAC” competition, and I do not plan to select a “winner”.  The write-ups I will post are not intended to be interpreted as an authoritative “last-word” or an analysis following the scientific method.  I am certainly open to suggestions and questions, and I don’t mind if people disagree.

I just want to mention that the Bricasti M19 SACD transport and M19 (and their M12 Series II) DAC have an I2S connection optimized for working together. Their DACs also have an optional internal network renderer.

@mitch2 - Thanks for allowing us to enjoy your evaluations and comparisons vicariously. It's a great opportunity to learn about these other products I've not yet had the opportunity to hear and experience. I'm curious to hear your thoughts on these different products. While I'm absolutely happy with my Merason DAC1 MKii, I'm curious about the sonic strengths of these other DACS. 

Thanks again for allowing us to enjoy the journey with you. 

@moonwatcher - I am just finishing up my write-up on the Mojo Audio Mystique EVO Pro, which will be my baseline for comparing against the others. LTA Aero will be next.  All the nice end of summer weather we have had this week is getting in the way of my evaluations!

Most of these are well above my price range, but I am interested when you finally finish your comparisons where the LTA stacks up in this list. Keep having fun. 

no_regrets

You're welcome, lot's of really smart people on these threads have helped me for the last bunch of years as well

All of that said, there is no substitution for your ears. In almost all of my tests with different gear (many DACs, DDCs, CD transports, and streamers), I have preferred the I2S connection almost every time (if the units have that I2S connection). On units that did not have I2S, I mostly preferred the AES/EBU connection.....that's my ears in my system, or in systems I know well.

One more point that should be noted, is that AES/EBU are digital cables (XLR connector type) that are 110 ohm cables, and NOT the standard 75 ohm cables like XLR analog interconnects

@vthokie83 Thank you for helping me understand.  I've been a vinyl guy for 50 years and am just now trying to add a nice digital source to my system.

Best wishes,

Don

no_regrets

Using the Jay's Audio CD transport as the example, here is the preferred order of connections (IMO). In each case the clock from the Jay's will be used, it's just how the clock is received (separate or imbedded, see my previous post):

(1) I2S if your DAC has that connection

(2) AES/EBU if your DAC has that connection

(3) SPDIF (either RCA, coax, or optical....whichever your DAC has)

The outlier is USB. Some streamers and or DACs (usually higher end gear) are optimized for USB, over other connections.

@vthokie83 

Yes it would, you'd want to keep the oven controlled crystal oscillator in the Jay's transport as the master clock

Great!  Thanks again for your patient explanations. 

@vthokie83 

When you say “Yes it would, you'd want to keep the oven controlled crystal oscillator in the Jay's transport as the master clock”

Do you mean.. then use the coax or aes balanced digital output?

Im just trying to understand. 
 

Thank you and best wishes to you!

Don

Yes it would, you'd want to keep the oven controlled crystal oscillator in the Jay's transport as the master clock

@vthokie83 

Thank you for explaining.

If the clock in a dac is, for example, a Femto, wouldn't it be advantageous to utilize the Jay's connections that bundle the digital data and clock together in order to utilize the Jay's superior clock?

stuartk

The Jay's CD transports do have an excellent OCXO clockl, their transports are excellent in my experience. The Jay's CD transports have 4 different connections: RCA unbalanced SPDIF, BNC unbalanced SPDIF, AES/EBU balanced connections, and of course I2S.

In all of those connections, the digital data and the clock are sent by the transport; and the DAC will use the transport's clock data.

Using the unbalanced RCA/BNC SPDIF connections, the Jay's will transmit the digital data and the clock packed together, in an unbalanced format, and the DAC will then unpack the data and clock, convert back to I2S, and then perform the digital to analog conversion. Some higher end DACs may have the ability to regenerate the clock signal.

The AES/EBU connection will transport the data and clock together, in a balanced format (balanced will do a better job of ensuring the data arrives correctly). That said, the DAC will still unpack the data and clock, convert to I2S, and then convert the digital data to analog.

The I2S connection will transport the data and clock separately, so no need for the DAC to unpack it from the data, and no need to convert to I2S for the DAC, and then the DAC will convert the digital data to analog.

In my opinion (and through some experience), I would use the I2S connection if possible, the AES/EBU if I2S is not available, and the SDIF connections as a last option. 

@ brbrock

Sorry it took me so long to respond...I don't go on forums every day.

LC = choke + capacitor

CLC = capacitor + choke + capacitor

In a CLC they use smaller chokes than in an LC power supply.

Most power supplies in audio gear are just C (only capacitors) and have no chokes at all.

LC is better than CLC and CLC is better than just C power supplies. 

As for tube DACs...

Let me start by saying that the DACs I designed up until 2013 were all tube DACs.

I found that tube stages are inherently noisy (usually <95dB SNR) and putting a tube stage inside of a DAC chassis tends to lower the performance. 

Keep in mind that DAC chips all contain solid-state op amps inside of them making DACs inherently a solid-state component.

If you were to reproduce a DAC chip with 100% tubes the DAC would likely be the size of a microwave oven and would have to cost several times as much. 

Don't get me wrong: I love tubes.

Tubes add what I like to call "attractive distortion." 

I just prefer to add a little "attractive distortion" to my system with a tube preamp and/or amplifier because I can always upgrade my preamp or amp as opposed to the often less than optimal noisy colored tube stage built into most DACs. 

Why am I saying that tube stages inherently have coloration and distortion?

Aside from the individual sonic characteristics of each specific brand and type of tube, all tube stages require an output transformer or capacitor between the tube and the output. Yes, even the so-called LTA Aero with their "ZOTL" output stage has circuitry between the tube and the output jack...it is in no way "direct-coupled."

OK...yes...there are actual OTL tube stages (such as Atma Sphere Audio) but they require BANKS of tubes.  

Transformers, capacitors, and exotic output stages all add a character and color to the music as well as degrade the purity of the music. 

Less is more.

That's why the DACs I've designed since 2013 are direct-coupled with nothing but a single Vishay "Nude" resistor between the amplification stage and the output.

On the positive side, a significant percentage of the better tube DACs do have LC or CLC power supplies which is likely why people find they have better timing and timbre than solid-state DACs most of which don't have chokes in their power supplies.  

@vthokie83 

QUESTION: My Jay's CDT2MKIII has an OCXO. How does such a transport affect DAC clocking ?

@soix no disagreement on the value of a DDC, I plan to give one a try. But for apples to apples, maybe best left out for the review. 
 

And of course, yes, @mitch2 should do what he wants , I am by no means trying to dictate the terms of the review. 

I have to disagree with adding a DDC. I feel that the DAC’s should be compared based on their abilities, without having the DDC safety net. The Merason has its own galvanic isolation built into the unit. If others do not include this, they may suffer in comparison, as it should be. 

@zlone I actually agree with you as most people probably do not have a DDC so a native comparison without a DDC would make a little more sense from that perspective, but it’s up to the OP although the comparison with a DDC is still really useful/interesting IMO.  I’m the very happy owner of an Iris DDC and was only pointing out that galvanic isolation is another benefit that wasn’t initially mentioned in addition to all the others that @vthokie83 nicely laid out.  I actually think almost everyone with a DAC should have a DDC because its benefits are that important and impactful, but that’s a story for another day.  And then there’s adding a better external clock — it never ends…

That last part "PSAudio/HiFi Rose/Silent Angel/Matrix/Pi2/Holo Audio all have I2S outputs." I should have noted are streamers or music servers

brbrock

Electrical engineers, forgive me if I misspeak anywhere below

I cannot comment on the DACs in mitch2's comparison, but I can comment on the benefits of a DDC with most (not all) streamers or CD transports.....and specifically the Denafrips Pontus II/Iris combination, but that applies to most other DACs. Sorry for the detailed information, but I appreciated the education when I first got it.

(1) Crystal Oscillator - The basic clock in the Pontus II is a standard (though very high quality) FEMTO clock. Crystal oscillators (clocks) and their performance are affected by temperature variation, thus the need to keep the clocks at as stable a temperature as possible.....but that, and the implementation of, can get expensive. The better the clock, the better the stability and the sound quality, the higher the price.

Most low to mid quality DACs have a FEMTO clock that has no compensation for temperature, thus minor fluctuations in it's performance.

The next step up is a TCXO (temperature compensated crystal oscillator), where the temperature is controlled by the use of thermistors and insulation of the crystal oscillator.

The next step up from there is an OCXO (oven controlled crystal oscillator), which uses an internally adjustable "mini oven" to keep the crystal at optimum operating temperature.

As I mentioned, the clock in the Pontus II is a high quality FEMTO clock with no temperature compensation, The crystal oscillator in the Iris is the higher quality TCXO temperature compensated crystal oscillator. The next step up Hermes and the top of the line Gaia use an OCXO oven controlled crystal oscillator.

(2) Galvanic isolation - This isolates signals by using magnetic components. All Denafrips DDCs use a galvanic opto coupler, optically and galvanically isolating the signal

(3) Optical isolation - This isolates the signal by converting to an optical transmission using lasers, thus eliminating electrical contamination......usually with an opto-coupler. All Denafrips DDCs use a galvanic opto-coupler, optically and galvanically isolating the signal

(4) USB - USB transmission does not contain a clock signal, it is assigned by the receiving device. USB directly into a DAC has the DAC assigning the clock, USB into a DDC has the DDC assigning the clock which would then be passed to a DAC. High end streamers do a very good job of transferring USB data, so less phase shift and jitter; and some with very high end streamers have reported little/no benefit from a DDC.

(5) AES/EBU and SPDIF - These signals do include a clock signal that is generated by the sending device, however the clock is imbedded with the data signal and must be separated by the DAC/DDC. Higher end DACs/DDCs will correct or even regenerate the clock signal, and some have the ability to turn that feature off if the incoming signal is superior

(6) I2S - This is the protocol that DACs (and other digital devices) use internally to process data, so any USB, AES/EBU, SPDIF signal must be converted to I2S in the DAC/DDC. The great thing about the DDC is that it handles this conversion, and then can (if the connection is available) transmit that same I2S data to a DAC. The I2S signal has a separate pinout to transmit the clock, so it does not have to be parsed by the DAC; the DAC just converts the digital signal to analog with the already converted I2S signal using the separate signal for the clock.

I suspect this is partially why so many people report that the I2S connection sounds best versus other inputs. Some external devices (streamers or CD transports) can natively output I2S, so a DDC might not be needed. Jay's Audio and PSAudio CD transports have I2S output, and PSAudio/HiFi Rose/Silent Angel/Matrix/Pi2/Holo Audio all have I2S outputs.

I think I agree with zlone, and feel that the ddc should not be used and should hear how each dac performs based on its own merits.  
 

However, this is Mitch2 experiment and can conduct it as he desires to.  
I feel grateful that he is sharing his experiences with us!

Best wishes,

Don

@soix I have to disagree with adding a DDC. I feel that the DAC’s should be compared based on their abilities, without having the DDC safety net. The Merason has its own galvanic isolation built into the unit. If others do not include this, they may suffer in comparison, as it should be. 

@soix - Galvanic isolation - good add.

In the digital audio world, a decent DDC offers tangible improvements for an $800 box! In the world of DACs, I believe there can be quite a variance in the quality of the USB input, which can also be negated by using a good DDC to accept the USB input and then output to the DAC using another type of connection..

A DDC 1. provides multiple output options from a USB input, 2. reduces jitter, and 3. may allow the connection of a master clock or sync directly to the clock in a particular DAC

I’d add a DDC can also add galvanic isolation for further noise reduction that many DACs sadly do not have. 

@brbrock -

• Here is a list of DAC chips from 2012 with performance comments by Antonino Scozzaro of Soundbsessive
• The SMc DAC-2 uses the CS4328 chip (good odnobitnik)
• The Mojo Audio DACs use dual AD1862 chips (20-bit – one of the best of the world’s Audio)
• The LTA Aero uses the AD1865 chip (18-bit, very good multibitnik, 2 DACs in one case - stereo)
• The Merason uses the BB PCM1794 chip (best of odnobitnik)
• The Benchmark uses the ESS Technologies ES9028PRO chip
• A DDC 1. provides multiple output options from a USB input, 2. reduces jitter, and 3. may allow the connection of a master clock or sync directly to the clock in a particular DAC (I believe, but am not sure, certain Denafrips DDCs/DACs may be used in this manner)
• The SMc DAC-2 does indeed have an optical input (Toslink), as well as S/PDIF via coax

@mitch2 and @vthokie83  and @trivema   I have a few questions about some of the equipment in the study.  Mitch do you know the DAC chip used in the SMc Audio DAC?  Also is part of the purpose other than correcting timing of a DDC to be able to change inputs?  Many DAC's do not have an optical input such as the SMc audio and Mojo Audio, because of this I am not able to connect the TV to watch movies etc.  

It was more challenging than I anticipated to choose a small group of music selections that were both representative of music I listen to, and also suitable to highlight attributes of the of DACs being compared.  I started by creating a new playlist in Roon, where I could accumulate and compare tracks, and I eventually chose a smaller group of selections that I have grouped and listed below.

Music Selections (Title, Artist, Album)

Jazzy,

• The Girl from Ipanema, Getz/Gilberto/Jobim/Astrud, from Getz/Gilberto (Remastered)
• Birds, Dominique Fils-Aime’, from Nameless
• Freddie Freeloader, Miles Davis, from Kind of Blue
• Take Five, The Dave Brubeck Quartet, from Time Out
• Babylon Sisters, Steely Dan, from Gaucho

Vocals

• Gravity (Live), Sara Bareilles, from Brave Enough: Live at the Variety Playhouse
• Steamroller Blues, James Taylor, from Sweet Baby James (2019 Remaster)
• Come and Go Blues, Allison Krauss, from Muscle Shoals: Small Town, Big Sound
• Angel from Montgomery, Susan Tedeschi, from Live from Austin, TX
• Come and Go Blues, The Allman Bros. Band, from Live at Alltel Pavilion, Raleigh, NC
• Like a Stone (Live at Queen Elizabeth), Chris Cornell, from Songbook

Rock

• Thorazine Shuffle, Gov’t Mule, from Live…With a Little Help from Our Friends
• Fell on Black Days (Demo), Soundgarden, from Superunknown (Super Deluxe)
• Smells Like Teen Spirit, Nirvana, from Nevermind (Remastered, 2021)
• Cortez the Killer, Neil Young & Crazy Horse, from Zuma
• Otherside, Red Hot Chili Peppers, from Californication
• Outside, Staind, from Break the Cycle

@vthokie83 and @trivema  - Unfortunately, I do not have the Denafrips Pontus II DAC with an Iris DDC to include as part of the comparison, or any Denefrips DAC.  I have considered trying a Terminator (in whatever iteration) several times but the timing or opportunity were never just right.  I did try the Hermes DDC in my system for a couple of months but I had integration and performance problems getting it to work properly.  I will say the Denefrips USA support team was very helpful and eventually sent me a new unit that worked, but I ended up selling it.  I do like the idea of using a DDC (for having a variety of output options and lowering jitter out) and I currently use the Singxer SU-6, which I found to be a basic plug-n-play unit that has worked perfectly since I installed it.

mitch2

It'll be interesting to see your findings, and what you hear in your system

Trivema & Soix

I still find the Denafrips Pontus II DAC with an Iris DDC via I2S to be the most musical, enjoyable, and fun DAC combo out there. I have upgraded every other component (preamp, 2 amps, speakers, cables, receptacles), but I still do not feel the need to rush out and replace the pair......I find them an incredible bargain

I have tested several $4,000 to $5,000 DACs along the way (I won't mention names because I don't want an argument), and still find my liking for the Pontus/Iris combo.

Yes I absolutely will upgrade my DAC at some point within the next year, and yes I know there is better sound to be had......but I will take my time to make sure it still has that fun and enjoyable sound that I currently have. I lust for a Lampizator Pacific or Poseidon, but that'll have to wait a couple of years

@agisthos - The only brand new unit is the LTA Aero, which was burned in at the factory for a week and has been in my system and turned on full time for three weeks, while playing music some of the time, maybe 30 hours.  The Merason is an original DAC1 that was upgraded to MkII months ago, and the others I already owned.

You really need to put a hundred hours on each DAC as well. Are they new units or 2nd hand?

I don't care what my Lampizator Poseidon measures, it's the best DAC for my system.  My second system has a great DAC (and great measuring DAC as well) which is 70% as good and certainly as enjoyable, small and really cheap now that it has been discontinued (half a dozen rave reviews), the Topping D70s.  To really beat the cheap Chinese DACs, one generally has to spend a lot of money.  Haven't heard the Schitt units but their new transport for $1200 is great, the Urd.  

@mitch2

I’m looking forward to your report and not only because we appear to have similar tastes in home decor. I expect my next upgrade will be the DAC. 

@trivema

I’ve thought about it, but haven’t. Mine is the original Pontus ll and besides some minor updates, the basic design is still the same. I’m gonna keep looking for now, but Maybe if a used one popped up, I might jump on it.

Thanks.

@mitch2 You certainly have major task in front of you here. I'm just in beginning process of comparing three different dacs, two being new purchases. What I've discovered is leveling the playing field is very difficult. I will be testing a single R2R dac to two sabre chip dacs, these sabre chip dacs usb likely to be optimal input, I2S for R2R. And then my system presently already optimized for usb, will be purchasing one of two top DDC;s in order to provide optimal I2S.

 

So, you're using Singxer SU-6 which I previously owned, while this is one ot the better DDC, there's still better out there, examples being Denafrips Gaia or Musician Phoenix. And then we have the question of optimizing usb inputs as well. Herein lies the problem when trying to compare dacs, optimizing inputs is the single largest variable in attempting to provide level playing field and extract maximum potential from all dacs.

 

 

The person who wrote " Comparison is the Thief of Joy" even though not being about audio in its context, certainly has created a saying that is worthy of taking on board when getting bogged down in audio equipment.

I’ll counter with “Ignorance is bliss.”  One person’s “bogged down” is another’s valuable opportunity to learn very helpful and useful information, especially in the context of this thread.  I choose to continually learn and enjoy doing it, but that’s me. 

@pindac Many thanks for your wise post and your gentle admonition to re-focus on what matters first: The music.

I am currently in the midst of spending far too much time researching the system I haven’t put together yet, and this is what I needed to hear. Thanks again.