• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Topping Centaurus R2R DAC Review

Rate this R2R DAC:

  • 1. Poor (headless panther)

    Votes: 22 7.5%
  • 2. Not terrible (postman panther)

    Votes: 70 23.7%
  • 3. Fine (happy panther)

    Votes: 145 49.2%
  • 4. Great (golfing panther)

    Votes: 58 19.7%

  • Total voters
    295
The dangerous myth of original purity must be taken into consideration in this craze for R2R which finds its source among audiophiles resistant to digital

PS. And funny thing, it was through a reversal of the situation that we got there...
Interesting
Forums where you find a category of audiophiles full of believes entertain the myths that they create themselves arround gear and the magical they can bring
I think that some audiophiles now play with digital sources, but still they wont understand mesurements but will think that expensive dacs are better
Take a dac that is 8 years old but from a luxury brand Vs a recent dac that is state of the art but from eversolo, or topping, it wont interest them and will believe the 8 years old dac is better and sound like crazy
Or they need to spend 6k in a recent dac to feel an upgrade
 
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.
Indeed a lot of people are confused and mix R2R with non oversampling filters. I’m not sure why.

That said, you don’t need them as per the theory. The zero hold DAC function will recreate the original signal, it’s good enough. Now, if we want to remove the artifacts related to zero hold and compensate for the roll off of sin(x)/x envelope, then analog filtering is a minimum requirement, and you’re right that today we do much better with oversampling filters.
 
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.
Ok, got you and I can only agree with your SINAD POV.
On price perspective, I see it differently.
 
Fact is that the market is flooded with DACs to the point that little has left for one of them to point out as something different.
Hence attempts like this.
Pointing to the traditional audiophile market (yes,along with its myths) is maybe a way to differentiate.

Thing is that this recipe is very strict,the R2R element alone doesn't cut it.Neither the fact that modules come from a somehow closer to this community company (Holo) who follows its unwritten rules (but not there yet,it's more of a satellite) .The first miss (to the hardcore community) is the digital VC (or the VC at all) .
I understand that they keep it for their pre,but...

And then is the fact that Topping has tied itself to the measured performance above anything else neglecting all else (despite the marketing stuff which is funny sometimes) and it's been strongly opposed the subjective stuff.Origin doesn't help either,along with some hardware failure and the fact one cannot brag a "built like a tank" device.

I don't know,I feel they should stick to things like E30,etc,it's these stuff that made them known.
 
0e14d7eb45ac444174a29c1c55159543f848061f.png
d3164e0b3b8d2bc5a9b25c5dd2d9394ac0f23653.png



Jitter and multitone of the Cyan 2 with oversampled DSD256 through HQPlayer. Retrieved from https://community.roonlabs.com/t/best-native-dsd-dacs-for-use-with-hqplayer/132298/

Not directly comparable though. Also DSD is handled through a different pathway on the Holo Audio board.
 
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.
Two nations separated by a common language? Apart from the first sentence, I agree with every word of that.
I was questioning why R2R, NOS and reconstruction filters were often lumped together when I thought they were separate things?
Is there something that ties them together that I don't know about?
I think the answer is "no". You can have a R2R DAC with OS. You can have a NOS deltasigma DAC.
However, I think you're saying you can't have any DAC without a reconstruction filter?
Here's the Holo May with and without over sampling - OS and NOS respectively:
1734257185501.png
1734257207174.png

In NOS mode, it doesn't even attempt a reconstruction filter, and here's the result, a staircase output:
1734257286348.png

This is much the same as Topping advertise with the Centaurus in NOS mode:
1734257433901.png

At least the May and the Centaurus have the option to disable NOS mode. Now, I'm still learning about NOS DACs (it does all seem strange to me, as in "why would you do that?") but to the best of my knowledge, the Holo Cyan and Cyan 2 operate in NOS mode only. There may be other DACs like that, I haven't figured that out, yet.
 
I was questioning why R2R, NOS and reconstruction filters were often lumped together when I thought they were separate things?
Ahh, that's a valid question. You are correct - I often see these two independent technologies decoder and filter merged incorrectly. You see people justify an R2R DAC just so they can have no filter. Removing the filtering seems to be the goal and the chosen method is to buy an R2R DAC. Clearly, with a modern chip DAC, isolating the filter into a separate, switchable board is not straightforward. So, if you believe filters are evil, you hate your cat and are rich enough to regularly replace your tweeters, a DeltaSigma from AKM or ESS won't cut it.

However, I think you're saying you can't have any DAC without a reconstruction filter?
I'm not suggesting you can't have a DAC without a reconstruction filter. Clearly you can. What I'm saying is that for correct playback, you MUST have a filter blocking artefacts above half of the sample frequency. The theory and practice of sampling mandates this.

(it does all seem strange to me, as in "why would you do that?")
And it seems strange to me also. You would not do it if you understood the basics.
 
Gees, what's the point of this DAC, it's expensive and measures worse than their normal offerings. Yes, must be to please people that for some unknown reason want an R2R DAC, what's the point - none! Most ASR members would write this DAC off after seeing this review, maybe even before seeing the review!
 
Gees, what's the point of this DAC, it's expensive and measures worse than their normal offerings. Yes, must be to please people that for some unknown reason want an R2R DAC, what's the point - none! Most ASR members would write this DAC off after seeing this review, maybe even before seeing the review!
Many are led to believe that there is some as yet discovered ‘magic’ in R2R/NOS/ Vintage chips / really expensive dacs , it makes perfect sense for the manufacturer.
Keith
 
Gees, what's the point of this DAC, it's expensive and measures worse than their normal offerings. Yes, must be to please people that for some unknown reason want an R2R DAC, what's the point - none! Most ASR members would write this DAC off after seeing this review, maybe even before seeing the review!
And a lot will not, and a lot more non-members.
 
  • Like
Reactions: MAB
And a lot will not, and a lot more non-members.
I'm pretty sure most ASR readers wouldn't fall for R2R magic - at least those that agree with the principles of the site.
 
What I'm saying is that for correct playback, you MUST have a filter blocking artefacts above half of the sample frequency. The theory and practice of sampling mandates this.
In practice it also depends on the "observable bandwidth". Which, in case of humans, ends at ~22kHz on a good day for young ears, following a low-pass filter function. This means the bandwidth limit of the observer will work fine as reconstruction filter if fs/2 is above that limit.
The only real technical problem with filterless NOS (besides the ZOH HF drop which can be compensated, though) is significant IMD distortion in subsequent stages (like tube stages). OTOH, once you have such strong levels that high up the additional IMD created by the images is negligible compared to the IMD from in-band frequencies, the signal is already broken.
 
Ahh, that's a valid question. You are correct - I often see these two independent technologies decoder and filter merged incorrectly. You see people justify an R2R DAC just so they can have no filter. Removing the filtering seems to be the goal and the chosen method is to buy an R2R DAC. Clearly, with a modern chip DAC, isolating the filter into a separate, switchable board is not straightforward. So, if you believe filters are evil, you hate your cat and are rich enough to regularly replace your tweeters, a DeltaSigma from AKM or ESS won't cut it.

I'm not suggesting you can't have a DAC without a reconstruction filter. Clearly you can. What I'm saying is that for correct playback, you MUST have a filter blocking artefacts above half of the sample frequency. The theory and practice of sampling mandates this.

And it seems strange to me also. You would not do it if you understood the basics.
Thanks, we're on the same page. Having said that I think R2R and NOS should be separate things, something has just occurred to me that might link them.

Here's my supposition. Suppose that R2R DACs produce lower levels of ultrasonic noise / images / spuria etc than other DAC types? Suppose you can't have a NOS deltasigma DAC because the ultrasonic noise would be too much for the rest of the system? Therefore if you want NOS it's got to be R2R? Maybe that was established long ago and everyone has forgotten about the reason ever since, but they do go hand in hand. Just a guess.

However, you can still use a slow filter like this MBL one, and get something similar:
1734262004284.png

The Topping D90 III and many others have a similar filter option where the stop band is pushed out to 35kHz:
1734262444762.png
 
Last edited:
To get full review you should show measurements of this units major feature which is DSP, turned on.
 
Thanks, we're on the same page. Having said that I think R2R and NOS should be separate things, something has just occurred to me that might link them.

Here's my supposition. Suppose that R2R DACs produce lower levels of ultrasonic noise / images / spuria etc than other DAC types? Suppose you can't have a NOS deltasigma DAC because the ultrasonic noise would be too much for the rest of the system? Therefore if you want NOS it's got to be R2R? Maybe that was established long ago and everyone has forgotten about the reason ever since, but they do go hand in hand. Just a guess.

However, you can still use a slow filter like this MBL one, and get something similar:
View attachment 414119
I really don't get it.
Why don't someone want some really decent filters like the Bricasti M1SE ones for example?
The particular one has the heritage to be well into audiophiles circles as well.

Bad marketing or incompetence to make such decent filters seems to me (judging by their rarity)
 
  • Like
Reactions: Ein
Back
Top Bottom