Topping Centaurus R2R DAC Review

[totti1965]

It's not, look again

Oh sorry I have corrected it before I read your post.

 

[Mikig]

That's not the case. Look very hard at the intermodulation chart. It's good at 'silent' and it's good at 'so-loud-your-ears-bleed'. It's poorer where the bulk of music is. This is common with ladder and R2R DACs.

The image below makes it look artificially better for extremes than it is for normal music.
View attachment 413994

Meanwhile this image below explains why. Notice the top-left and bottom-right of the chart are good (which is why the figures in the above image are good), but the music happens in the middle of this slope which should be flat. This is where distortion modifies the music:
View attachment 413995
A good DAC will measure well at -20dBFS, -30dBFS, -40dBFS and have a smooth slope. This DAC would show poorer results than a DeltaSigma (even an ESS with the IMD hump).

yes you are right, but we are not talking in absolute terms. In its category, R2R, is tested as the best.
I think that from the Amirm test we can see that the performance is not that of D90 III, but all in all the average of the panels place it as a Dac not problematic in terms of fidelity and with some surprising values for its category. this on paper.
A different story concerns the aura that R2R brings with them in the world of enthusiasts.
Then as they say: "perfection is in the eye of the beholder" in this case of the listener….de gustibus .....
I personally would buy one to form my own opinion on listening, I have no prejudices against any technology.
Two problems afflict me.
The first is that I am tired of doing listening tests, I prefer to listen and enjoy music, Now it is increasingly difficult if not almost impossible to establish at the level of sound output in a system with speakers peculiarities or defects of electronic or digital devices. I no longer want to listen to the same song every day for 30 times to try to understand things that I would barely hear by now .....
Eventually if I do tests or critical listening
I focus and make general system adjustments now, so I focus much more on speakers and listening room.
the second is that with the same money, I can enrich my collection with devices or speakers that intrigue me more ...

 

[totti1965]

It would be interesting to know where dCS land in terms of performance in comparison. Is there any billionaire here to send a unit to Amir for testing?

dC - who?

 

[beefkabob]

Holo makes the R2R modules:

View attachment 413841

The only reason I bother to rear R2R DAC reviews is for the sexy shots of tiny resisters in neat rows. Oh yeah, baby! Who's a dirty, dirty analog design?

 

[Mnyb]

Unfortunately, most what you wrote is incorrect because you are confusing decoding and filtering by mixing them together.

Let's start with reconstruction filters. You MUST have them if you have any hope of reproducing the original recording. This is a baked-in consequence of digital sampling theory as invented in the middle of the last century by Whittaker, Nyquist and Shannon. It does EXACTLY the same thing whether you have a current SOTA DeltaSigma, an original Phillips 4x oversampler, a ladder or R2R DAC. The filter's job is to allow everything through without any impact for up to half the source sampling rate and then to plunge precipitously down to block everything above half the sampling frequency. Sure, with certain test signals, filters ring, but good ones don't when playing music.

Then let's look at the DAC itself. Assume we have a mathematical system where 1 = the quietest breath of a gentle breeze and where 256 = the loudest bit of an explosion. This can be encoded in an 8-bit digital word. When all the bits are 11111111 = 256; when all the bits are 00000000 =1. The challenge is converting these bits into a voltage which can make speakers move. Suppose we set the first bit flipping on to be 0.01V, when the second bit turns on, it has be be double that at 0.02V. The third bit flipping on is double again - 0.04V. This 2x mathematics with each bit needs to be extraordinarily accurate. The simplest architectures to understand are ladders and R2R DACs where each step is done with precision resistors. It's easy to understand, but spectacularly hard to get right. And if you do get it right once, it will drift with temperature and with time.

The result is - even the very best R2R and Ladder DACs struggle to get close to the near-perfection achieved by DeltaSigma. Where they are at their worst is not at the very quiet or very loud part, but slap bang where the music is. They add distortion. It's probably not possible to hear this distortion, however. BUT this has NOTHING to do with filters.

Yes one bit DAC then ultimately modern delta sigma DAC’s where born to solve all those linearity problems resistor ladder DAC’s inherently have that can’t really be fixed.
In the of one bit case it’s intuitive even to a layman if your one and only DAC’s bit “drifts” it’s just a subtle level change and does not alter the relationship between any bits in the sample it simply can’t have trivial linearity problems by design.

To make it work you then need complex noise shaping in these DAC’s so the whole thing works by mathematics ,this is more stable than laser trimmed precision resistors but non intuitive and incomprehensible and less romantic than a big varm chunk of metal and expensive components ?

The noise shaping ultimately creates ultrasonic junk as a byproduct , but this has a simple solution, a filter . Again easier to implement and more linear.

Hard to stress enough the fact that a DAC ultimately does not work without the reconstruction filter it’s an integral part of what any DAC is doing. Turning these off leaves you with some kind of intermediate stage signal not meant to be listened to ,you get those stair steps that does not really exist in proper digital audio and timing no better than the distance between samples ( it’s much much better with a proper reconstruction filter )

Suppose that by design you can have different “garbage” signals in NOS mode from different DAC’s

 

[dlovesmusic]

Well, what do you know - it's not quite as good as the Centaurus. The Cyan 2 is rather better though, and is probably similar to the Topping.

Measurements of HoloAudio Cyan DAC&HeadphoneAmp - L7Audiolab

台式设备 众所周知，我挺欣赏HoloAudio的设备，就实来说，我和HoloAudio的开发者Jeff关系不错。但是，他一直有一条产品线我没有测量过-----青（解码耳放一体机）。今天要发布的就是网友送测的这台机器

www.l7audiolab.com

That’s the original cyan from a number of years ago. Not the cyan 2 that launched in late 2023

 

[DualTriode]

Filters modify the input signal and with it, change the nature of measurements generating results that are not meaningful. I can arrange where they don't impact the measurement which is what I did with the Topping D50 III: https://www.audiosciencereview.com/...ng-d50-iii-balanced-dac-with-eq-review.53856/

Thank You,

I thought that PEQ was Parametric Equalization.

Are there any DAC's that use DSP for Parametric Equalization?

Thanks DT

 

[GWolfman]

I Was listening to one of my favorite tracks from Civil Wars, the remake of Billie Jean

Hey, hey! I’m in good company! I love those two, too bad they’re not still making music and I never got to see them live. :cry:

 

[Eldus]

I'm not aware of any devices, but if you want to play around with distortion to see what it sounds like, then @pkane 's "distort" can do it on a PC.

If just interested in harmonic distortion (and if you are looking for "pleasing" ditortion, you probably are) then his pkharmonic plugin might be more interesting.

Analog Obsession makes free (donationware) plugins some (VST2) can be used in equalizer APO if one want to play around with distortion.

 

[binaryblaze]

Thank You,

I thought that PEQ was Parametric Equalization.

Are there any DAC's that use DSP for Parametric Equalization?

Thanks DT

To name a few:

RME's ADI-2 series
Qudelix 5K
JDS Lab Element IV
Topping D50 III and D90 Discrete
FIIO K19

 

[Mnyb]

Thank You,

I thought that PEQ was Parametric Equalization.

Are there any DAC's that use DSP for Parametric Equalization?

Thanks DT

All uses DSP of some kind it’s not analog eq .

Good examples are the WiiM Pro+ and WiiM ultra for example, these are streamers and DAC’s and could serve pre-amp duty .

 

[Palladium]

Getting an R2R to measure this well is a real accomplishment from an engineering standpoint. But I don't understand the marketing choice here. I assume there isn't a lot of overlap between tweako subjective audiophiles and Topping customers, who can get more performant DACs from Topping's own catalog for much less. So who is this for?

Because if you are an audio manufacturer would you say no to harvesting $$$ the some of the most gullible people on the planet?

 

[BeeKay]

Because if you are an audio manufacturer would you say no to harvesting $$$ the some of the most gullible people on the planet?

Topping used to be down to earth with the interconnects they sell. Let’s see if this changes

 

[Waxx]

It's a good dac, despite it's R2R. And that is a accomplishment that i was not expecting. My main concern about Topping stays (durability), but it shows their level of engineering skills. Not that i will buy such dac, chip based dacs are better and cheaper still, but for those who want an R2R, there is one now that is transparent, beyond the resolution of our ears...

But for less than that price i can get a MiniDSP Flex, with 4ch out dac in higher quality, + an quiet advanced dsp and dirac room correction. So...

 

[ttt]

Never understood these things. R2R DAC is similar to making OPA by discrete. Both smile-making nowadays hype to sell it for whom who has less engineering knowledge It's all against the physical principles. The IC technology is very advanved today. On a dye with litography both DAC and OPA circuits can be made with much more precisely, with very tight tolerances and smaller sizes, resulting magnitudes better THD and noise performances.

 

[NTTY]

Thanks for this review, Amir. I'm going to vote "Not Terrible" because it costs more for being an RTR DAC than a comparable Sabre unit, AND it has measurably inferior performance. However, the decrement in performance is probably inaudible if set properly, but the big problem is there exist settings on the unit, which if employed, could actually lead to damaged speakers.
So it's a dangerous toy that should not be put in the hands of newbies or children. I could probably have voted "Fine" if not for the possibility of a blown tweeter for the naive user.

If you’re talking about the selectable NOS mode filter, then it’s the case with many DACs, starting with the RME ADI for instance.

 

[MaxwellsEq]

yes you are right, but we are not talking in absolute terms. In its category, R2R, is tested as the best.
I think that from the Amirm test we can see that the performance is not that of D90 III, but all in all the average of the panels place it as a Dac not problematic in terms of fidelity and with some surprising values for its category. this on paper.
A different story concerns the aura that R2R brings with them in the world of enthusiasts.
Then as they say: "perfection is in the eye of the beholder" in this case of the listener….de gustibus .....
I personally would buy one to form my own opinion on listening, I have no prejudices against any technology.
Two problems afflict me.
The first is that I am tired of doing listening tests, I prefer to listen and enjoy music, Now it is increasingly difficult if not almost impossible to establish at the level of sound output in a system with speakers peculiarities or defects of electronic or digital devices. I no longer want to listen to the same song every day for 30 times to try to understand things that I would barely hear by now .....
Eventually if I do tests or critical listening
I focus and make general system adjustments now, so I focus much more on speakers and listening room.
the second is that with the same money, I can enrich my collection with devices or speakers that intrigue me more ...

I change my gear every couple of decades and do no listening tests except when changing gear. The listening tests confirm my brain and ear are not as effective as test equipment. The rest of the time I use the gear to listen to music.

For 80% fewer dollars you can get a better DAC than this.

 

[NTTY]

. This is where distortion modifies the music:
View attachment 413995
A good DAC will measure well at -20dBFS, -30dBFS, -40dBFS and have a smooth slope. This DAC would show poorer results than a DeltaSigma (even an ESS with the IMD hump).

Per the graph, IMD stays below -80dBr from -20dBFs to 0dBFS. And even if we are indeed talking easier distortion to ear, I personally failed to identify IMD lower than -50dBr.

 

[Gremlins]

Money.

I would say to satisfy audiophile believes

 

[MaxwellsEq]

Per the graph, IMD stays below -80dBr from -20dBFs to 0dBFS. And even if we are indeed talking easier distortion to ear, I personally failed to identify IMD lower than -50dBr.

I'm confident that I won't be able to hear this DAC's limitations, either. But I also feel the SINAD score is overly flattering, and I can't see the point of a device which can be bettered for less money.