dCS has recently announced a new DAC and analog output board they refer to as APEX.  This board will be available standard in all new Vivaldi and Rossini DACs.  It is also being offered as an upgrade to existing owners.


I have had my Rossini DAC for just under 6 months and was curious as to whether there are noticeable improvements in the presentation with the new APEX design.


Steve at JS Audio (Bethesda, MD) was kind enough to allow me yesterday, for just over 3 hours,  to “A/B” the (now previous) Rossini vs the new APEX model.  I provided FLAC and DSD files of music I have listened to repeatedly over the last six months on my Rossini.  The files were on a solid state USB drive that he connected through his network server and I played the files with Roon.


It is important to define the system used for the comparison as the equipment will most likely influence the presentation.  Steve had set up Wilson Audio XVX speakers driven by D’Agostino preamp and dual mono amps.  The speaker cables were Nordost Odin.  The DACs were connected to the preamp by XLR balanced connections. An Everest power conditioner was apparently being used to filter AC.  The room was well conditioned and of course, per Wilson Audio, the seating had been placed precisely.


Steve was careful to demonstrate that the filters, maps and volume levels were set identically on both DACs.  The system was such that I merely pushed a button on a remote to switch from the Rossini to the Rossini Apex.  Being digital files, I could repeat segments of the music as I switched DACs so that the limitations of auditory memory were minimized as far as possible.


One other potentially important note:  My own system consists of the Rossini DAC connected by XLR to a Rogue Audio RP9 preamp and then Rogue Audio Apollo Dark mono amps.  My speakers are Sonus Faber Amati Traditions and my cabling is Nordost Valhalla 2 throughout. I send digital music files to the DAC from my Mac Pro using an ethernet connection (through a router) and Audirvana. My ethernet cables are Cat 5 unshielded per dCS’s recommendation. My network router is a standard one, not specifically designed for music. I do use a Puritan filter on the AC.


The details of the two systems are important because the Wilson’s and Sonus Faber speakers are at opposite spectrums of “house sound”.  The Sonus Faber are known for their neutral to warm tonal qualities and while quite articulate and detailed, they are very “musical” with excellent representation of instruments.  The Wilson’s are known for their analytical detail, almost clinical, neutral to “cool” house sound.  Furthermore, the D’Agostino is solid state vs. the Rogue Audio tubes (even though Rogue Audio is often stated to be the least “tube like” sound of that genre of preamps and amps).


So, it is not surprising that I found the XVX speakers to be highly, indeed analytically if not clinically, detailed, very precise, very articulate.  This is not a “negative” when comparing this level of DAC. The tonal qualities of the Wilson was definitely “cooler” than the Sonus Faber but still very close to what (as a former French horn player) I would expect for instrumental sound.


The music selected for this comparison was all of the classical or jazz genre with one or two exceptions. NO rock, pop or heavy metal music was auditioned. The volume level was moderate, certainly not “loud”.  The volume setting, once adjusted to my preference, was not changed during the 3 hours of listening.







THE APEX (in comparison the the “previous” Rossini) :


  1. In general sounded “louder”, significantly so, even though as stated above, NO changes were made to the volume controls (levels). I believe this “illusion” reflects the lower noise level of the APEX.  More “data” and less “noise” is probably perceived by our brain as “louder” since our auditory system is not “subtracting” the noise from the incoming signal.
  2. Its bass had more impact, more punch, more enthusiasm when called for. Its bass was NOT, however, diffuse, muddy, blurry, or otherwise characterized by a “subwoofer” sound.  Rather the bass WAS clear, articulate, resonant, and subtle differences in the musician’s interaction with the instrument were evident. (e.g. the bowing or fingering of the double bass, the way the drummer hit the tympani, etc.) The bass notes had a distinct frequency, not merely a “boom”.  This was particularly apparent when the music incorporated an organ.  The lowest notes of the organ pedal were distinct, each note of even the lowest chords.  Of course, the XVX’s capability at the lowest frequencies certainly helped to make this difference more pronounced— but the point is, that the difference WAS clearly evident.
  3. Its sound was not as homogenized or thick.  Large full orchestral passages with every section playing different “lines” of the composition fortissimo were clearer, more distinct and each section could be distinguished and followed. At first, the original Rossini sounded “better”, “fuller”, but then I realized that this was an auditory illusion— the “fullness” was a lack of detail, a subtle blurring or homogenization.  The APEX sounded “thinner” until I realized that it was presenting more resolution and the lack of “noise” or “filler” between the notes created what initially was erroneously considered a “thinner” sound.
  4. It presented soft (pianissimo) passages more discernibly.
  5. Its presentation of quick piano notes, as occur in a jazz composition, defined  “Tickling the ivories”.  Cymbals shimmered and “faded” when they were suppose to.  I tried to discern how this was accomplished and concluded that it was NOT by clipping the notes.
  6. It similarly, presented each musical note more clearly. Again I do not feel this was from “clipping” but rather from a greater separation of the notes, more space between the notes.  Perhaps this is secondary to dCS’s claim of a lower noise floor, no noise filled the gaps between the notes.
  7. Its soundstage certainly varied with the recording.  Overall, the APEX’s soundstage per se seemed deeper. Sometimes it also seemed wider, but I noted that with both DACs, the XVX seemed to prefer presenting the orchestra or group (just) between the speakers (at least more so than my own Sonus Faber system).  If the recording allowed, there was definite placement of musicians, especially front to back more so than with the original Rossini.  Jazz recordings still placed the performers “in the room” and the listener close to the musicians. Orchestral pieces, when so recorded, reflected the venue better than the original Rossini.  I could discern the “echos” and “reverberations” from the concert hall, or in the case of several organ selections, the church, to a greater and clear degree.
  8. It presented the organ’s pedal notes with more vibrato, pulsating character than the original Rossini,  more attuned to what I have heard “live” and the upper octaves had more reediness that was probably very representative of the actual instrument.
  9. It presented brass instruments with accurate timbre and the “tonguing” techniques could be readily discerned.  Similarly, the bowing technique of the strings was more clearly differentiated.
  10. (10) It presented voices more realistically, lyrics more clearly.  (I note, however, that I prefer the tonal character of the Sonus Faber system to the XVXs in this regard.)


Noteworthy, the treble on the APEX was slightly harsh, bright, close but not quite stringent on many recordings, in contrast to the “original” Rossini.  In fairness, however, whereas the original Rossini had been in use for many months and was well broken in, the APEX was literally straight out of the box with perhaps one hour of use before my audition. I know that my own Rossini took a while to “break in” and the treble lost any hint of brightness or harshness.  So, this may be the explanation for the APEX’s treble character.  If so, then perhaps the other differences will become even more apparent with adequate break in.



A long list of differences, but in terms of the magnitude of the change, I would definitely say it is NOT a tsunami; not even waves on a stormy day.  More like a gentle ripple or swell on a really nice day. If I had to assign a percentage, I would argue the improvement is 5 - 10%. Noteworthy, this is based ONLY on the particular Wilson Audio / D’Agostino system.


dCS states that in addition to changes in the Ring DAC, per se, the output stage has also been reworked.  This could mean that the amount of change noted by the listener could vary depending on the preamp/amp into which the Rossini feeds its (preferably) XLR signal.  Thus, I would like to try the APEX on my tube and Sonus Faber based system to determine the degree of change (hopefully all positive) for a system at the “other end of the spectrum” from the one used for this comparison.


Partial list of the music files used for the audition:

The Trumpet Player, track 21.

Being. Track 1

Holst Planets- Buzz Brass and organ. Track 4

Lazzio Marosi Tuba Concerto, track 1

Janoska Rev, track 2

Color Music, track 6

Hovhavness, Symphony #22, track 3

For Beauty of Earth, track 10

Bach Cello Suite vol 1, track 18


Thanks again to Steve for his hospitality.


the big question is how much to upgrade the Rossini to Apex?  I've poked around a little and they don't seem to want to answer this question just say to contact your dealer.  I'm gonna guess 5K.  You kind of lost me when you said the Apex sounded brighter and thinner, I certainly would not want any part of that kind of sound added to my Rossini.  


Thanks for the great insights! Unfortunately, DCS has priced me out of their product line. I was saving for a Rossini. Now the price is into the stratosphere. Even the Bartok's price has increased significantly over the years without any hardware upgrades. Not sure if this marketing strategy will pay off. No other DAC manufacturer has raised prices as to the cadence of DCS (lumin, MSB, etc.). I'm a little sad, maybe heartbroken, but my money has to go to another manufacturer, which presents a better price/performance ratio. 


I fear you may have misread my post.

The APEX is NOT "thinner".  This is a transitory illusion created I believe by the fact that the APEX has less noise, more space between notes and musicians and hence the sound at first is not as "dense".  When you listen a little longer, the illusion dissipates and the music is more coherent, more detailed.

Also, I believe I mentioned that I suspect the "brightness" in the treble is due to the fact that the APEX had only just arrived (literally) and had not been broken in.  My own Rossini (not APEX) also sounded bright initially, but this resolved after a few weeks.

dCS has not posted upgrade prices, but JS Audio informs me that the price will depend on when you got your Rossini.  Apparently, if it is within a certain period, the upgrade may be free or very little.  If your Rossini is several years old, it will cost more. Only the dealer can determine your priced, but it doesn't cost to ask.

Thank you for the review. I am a Rossini + Clock owner. I bought my unit from JS Audio actually.


Cost of upgrade for both Rossini and Vivaldi is $9k. They share the same Ring Dac + Analog output board, hence the same cost. The upgrade involves swapping boards and replacing the faceplate in the back which indicates it is an APEX version (it is just cosmetic).


There is no change in the Ring DAC per-se other than board layout of some traces, the analog output stage is the main change. For this reason I would definitely say you need at least 100+ hours of break in to compare these two units. Given the change in the output section, I also think that the outputs need to be level-matched for a true comparison - just having them at max volume is not enough.


One question: How were you playing the files? USB stick into USB2 then Mosaic? Roon over USB? Roon over network?




Steve at JS Audio indicated that the two DACs were level matched.

The USB drive was connected to his network server and I was selecting the DAC and files remotely.  I believe he was using Roon over his ethernet network, however, I will have to confirm this since I know he sometimes uses dCS's Mosaic over his network.

The dCS site has a long article on the APEX.  I interpreted a couple of paragraphs to suggest that in addition to merely trace changes in the Ring DAC, there were a couple of transistor modifications as well.  

Definitely agree with respect to break in time which is why I mentioned this in the review.  In other words, I expect to detect more improvement once the break in has occurred.

On the other hand, the changes in the output section may make the preamp and amp's associated with the Rossini more of an issue,  for better or worse.  

Steve suggested that the pricing on the upgrade will depend on the age of your Rossini, i.e. if less than 6 months old, the price is considerably less.

Question: If the same board is used in both the Rossini and the Vivaldi, how much difference is present between these units?

excellent write up ! you went to a bit of work to help us, thank you !

A bit more detail on level matching desired…but tgat is always the case..

Enjoy the music and let us know if indeed you go for the upgrade.


I got it from a trusted source that the main upgrade was the analog output stage. Not sure where you're getting the sense that the Ring DAC was changed at all. 

Ok on the matched levels, I didn't get that from the review above.

The Ring DAC / Analog output board has always been the same in Rossini and Vivaldi. So is the Ring DAC software - not the case with Bartok thus far, which runs Rossini v1. 

I can imagine there might be an accomodation for people purchasing the DAC in the last six months - I have no idea. The price I quoted is the official price of the upgrade.

As for pre/amp matches with a different output stage - sure. Like I said I don't really know. I very much doubt that it will make much of a difference in terms of match tbh, the dCS "house sound" is largely determined by the DAC.

As for what's the diff between Rossini and Vivaldi if the boards are the same, well obviously the power supplies on Vivaldi are not only more and separate, but you dopn't have the network board sharing a ground bus with the DAC for example (which you do with Rossini). There's no doubt it's not the same.

9K. what a joke. Perfect for rich and nuerotic DCS owners. I can hear bit more shimmer in the cymbals. Sign me up.

Thanks for the detailed write up.  Very comprehensive 



Thanks for the time and effort taken to share your listening session. Of interest to me since I am considering having the Apex upgrade done to my Vivaldi and the system you listened to at the dealer is similar though not identical to my own (D’Agostino Momentum electronics, Wilson Audio). I’ve heard the improvements made to a friend’s system with the Rossini Apex upgrade and they were significant.


It is my sense that any residual harshness or brightness you experienced with the Apex Rossini you listened to will dissipate with break-in, since I heard none of that when listening to my friend’s system. In fact, it is the best I can recall his system sounding, ever.

I’m getting my Rossini  done in a week I will give you my opinion as soon as it gets here. I hate bright or harsh so I wouldn’t send it in if I thought that would be the result. It would be nice to hear any one’s personal experience with this. 

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Craig,   So how long of a break in do you think is to be expected? Do you prefer the upgrade over the original in every way?

The break in is gradual, so I am not sure exactly how many hours are required.  I believe at least 50 and maybe 100 to the "final" sound.  The differences are certainly there as originally noted and I do prefer the upgrade.  I think that the "output" is also "better" in that I note a decrease in the volume setting on the preamp (XLR connections) for the same "loudness" suggesting more clarity and articulation. Whether this reflects changes to the Ring DAC or the output board is unknown since DCS will not reveal what they actually changed.   I run 6V output to the preamp because it seems to have more dynamics than the 2V;  note the preamp is a now an ARC REF6SE but I noted the same on my previous preamp, Rogue RP9. Hope this helps. Craig

Just any FYI for comparing DACs.

A great way to compare DAC's is to use a neutral preamp with identical input type (XLR or RCA). Connect each DAC to a preamps input. Assuming you need a streamer, then get 2 identical streamers.

The key is to use GROUPED STREAM on ROON so that the music is sent to both DACs at the same time. To compare the DACs just flip back and forth on the input selector of the preamp.

I use an uber neutral Benchmark LA4 preamp and Sonore opticalRendu streamers to compare 2 DACs. I can also adjust the volume via a BOOST on the preamp if one DAC is louder than the other.


I have a Valhalla 2 power cord.  The DAC is connected to the preamp by Valhalla 1 XLR.  I transfer music to the day via Ethernet.  Per the recommendations of DcS, the ethernet cable is an unshielded CAT 5 purchased from the Amazon site. (Ironically, DcS does not recommend an "audiophile" ethernet cable and specifically warns against a shielded cable.)   DcS recommends using XLR where possible, and I certainly heard an improvement over Valhalla 2 RCA cables (which I sold to get the XLR cables).  I am in the process of experimenting with other brands of power cables, specifically, Shunyata, and there is certainly a difference. For example, the Shuynata Sigma NR (current version) provides more articulation and separation in complex orchestral pieces and a deeper soundstage, BUT, while the base is very articulate, it lacks "resonance" or "fullness" (like a circle completely, but lightly shaded in vs completely but darkly colored in). However, the Shunyata cable I am testing is brand new, just out of the box, and I do not know how much of the lack of fullness or impact of the bass (and a slight brightness in the treble) is merely due to lack of burn in vs the inherent character of the cable.  (The Valhallas are several years old and well broken in.) This remains to be determined.

Every cable definitely makes a difference!   I hope this helps.


I just got my upgrade back a couple weeks ago and the sound is VERY lean and bright compared to before the upgrade.  I can hear more detail but the musicality is not there. I assume it needs time to break in. Did anyone else have this problem at all. If so how long before it settles. 

So I got with Emron of DCS and he spent about 30mins on the phone walking me through all the setting on my Rossini Apex and explained the function of each. Then he walked me through changing settings to what he thought was best. So organic now with tons of resolution.  Now this thing has really come alive. Now I see why everyone is raving about it. May very well be the best sound I’ve ever had.  Great company!