Topping Centaurus R2R DAC Review

[amirm]

This is a review, detailed measurements and listening test of the Topping Centaurus R2R stereo balanced DAC with PEQ filter support. It was sent to me by the company and costs US $999.

The unit has the elegant look of the new Topping DACs with high resolution, high contrast screen, nicely highlighting the volume level. It is fully graphic and can be changed to show spectrum, VU, etc. The included Bluetooth remote felt like it had a slight lag to it. Nothing serious but I don't remember this before. There is no rotary volume control. I use the remote for home use but on desktop, a rotary control is nicer for quick adjustments. Back panel shows the nice feature set we have grown to like from Topping:

Of note, we have the very useful trigger in/out for automatic turn on/off of downstream amplifier.

As the heading indicates, this is Topping's first discrete "R2R" DAC instead of using an integrated DAC solution. R2R performance can range from close to awful to respectable -- but never as good as IC based solutions. Let's see where the Centaurus lands. All tests are in default 4 volt mode instead of 5 volts (and "PRE" mode).

If you are not familiar with my DAC measurements, please watch this video first:

Topping Centaurus R2R DAC Measurements
As usual we start with our dashboard with XLR output:

This is better than I expected! Topping says THD+N is better than 0.0005% and we are getting half of that, resulting in the Centaurus landing in our "Excellent" category:

Harmonic distortion is higher than state of the art but all peaks are below -120 dB, making them inaudible.

RCA performance is naturally a bit lower:

Noise performance is essentially state of the art:

Jitter test output is not as squeaky clean as we normally see from Topping but is transparent:

Distortion was kept in check with our punishing 50 Hz tone into 600 ohm load:

Where we go sideways with R2R is in mid levels:

We have about 20 to 25 dB more distortion and noise at -33 dB than state of the art DACs. The quietness that topping brings to the table shows up at the start of the sweep where distortion is still very low.

Linearity however, has taken the smallest, negligible hit:

Edit: forgot to include multitone:

I was disappointed that none of the filter settings resulted in flat frequency response to 20 kHz:

On the other hand R2R fans get full menu of what they are asking with myriad of filter settings.

With default filter, there is still some out of band noise to reduce performance but impact is low:

Go to "non-oversampling" mode and ultrasonic noise shoots through the noise, causing that off-the-charts green line. Best not to have a tweeter that attempts to go above 20 kHz!

Topping Centaurus R2R DAC Listening Tests
I gave the DAC a quick test to see if I can the magic of R2R DAC. Connected the XLR output to Topping A90 headphone amp and drove the Dan Clark E3 headphone with it. I Was listening to one of my favorite tracks from Civil Wars, the remake of Billie Jean on the RME ADI-2 Pro. After quickly moved the headphone jack to Centaurus A90 chain, I noticed the highs collapse a bit but raspiness of the Jean-Paul White became more pronounced and pleasing! Was quite a surprise until I plug the headphone back into the RME, cranked up the volume to similar level and it too produced the same sound. Teaches me not to do sighted tests like this.

Conclusions
Objective performance of Centaurus seems to be the best that can be done with R2R technology. Topping brings to the table ultra low noise, equalization and great packaging, offsetting some of the shortcomings of that technology. Ultimately it can only polish that so much. Fortunately, distortion levels are likely still well below audibility, sans the rolled off highs that may be audible to younger folks. They should keep in mind as they change filters that the roll off changes with it.

Once a month someone asks me what R2R DAC they should buy. They say they have tried all the ESS/AKM DACs and want to play with something new. When I tell them I have nothing to recommend, some accept that, but others downright get angry with me! Now I can tell them to go and get the Centaurus and sleep easy that it at least doesn't compromise much fidelity.

While I would not buy or use an R2R DAC, I am still going to recommend the Topping Centaurus for those who want an R2R technoloy.
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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

 

[amirm]

Reserved for @AdamG to kindly post the specs.

Manufacturer Specifications:

TOPPING Centaurus R2R Digital to Analog Convertor (DAC)

shenzhenaudio.com: professional headphone, earphone, amplifier, dac, decoder, hifi player, cable supermarket. you will find good price here.

shenzhenaudio.com

 

[Mnyb]

The treble roll of seems small but it’s over a wide range so potentially audible .

Voted not terrible, but the product is not that bad ? What to weight into the judgement ?
A hand cranked 78,s rpm mechanical gramophone could be beautifully done and something to be had , but ultimately performance is not good ?

Anomalous product for an anomalous market

 

[GXAlan]

How does R2R approaches differ from something like the Marantz SA-10 with its discrete DAC approach? It seems like this is just mechanical watchmaking for audio?

 

[Rja4000]

Well done !

As you say, now you have a scientifically validated answer to those believing in R2R fairy tales : it's for sure not better, but, well, drawbacks (while still measurable) are limited here.

At least if care is taken in level matching between this DAC and the amp: if you have to always run it at -30dB, intermodulation distortions may become somehow noticeable.
So it's probably better to use this DAC at fixed output level and an integrated amp to control overall volume.
Correct ?

 

[Mnyb]

This is one of the best examples of R2R currently. They should just remove the the NOS 2 filter setting altogether for public safety, just like mandatory seatbelts and other regulations pure dunning Kruger territory to be fa filter tinkerer imho .

R2R is usually not this good so kudos for the very real engineering effort , but why ?

 

[unpluggged]

but why ?

Money.

 

[Sokel]

I seems like Holo gave Topping the technology and R2R modules but they kept a little performance advantage for themselves:



Other than that,another DAC.Would be great to see EQ impact down low to this and all that uses EQ as it becomes standard.
Fail to a ruler flat FR is a miss though,a major one.

Thanks Amir!

 

[Power Pop 23]

Meh,

A review of a DAC......

Time to vote. Where should Amir spend his testing resources?

I am sure if Armin would like a poll on his rather argumentative question he would have made one himself. I strongly doubt this thread here will change anything, so it is rather a discussion about its formulation and this poll even if some wish differently.

audiosciencereview.com

 

[MaxwellsEq]

The intermodulation graph demonstrates why not to buy this DAC. Why choose a product which is good at maximum signal and good at silence but poor in the middle (where music actually happens).

Because it's OK at max and at silence, it gets a higher SINAD score than it deserves. The test at -12dBFS that @NTTY does would be more useful here, since the current crop of chip DACs would stay in "Excellent" and this would probably drop out.

 

[Sokel]

. The test at -12dBFS that @NTTY does would be more useful here, since the current crop of chip DACs would stay in "Excellent" and this would probably drop out.

Actually a lot lower than that.
I been watching around electrical levels at well recorded music at line level and they all bang at an (additive for spectrum) -30dB to -20dB with the peaks reaching around -15dB and very rarely above that.50 to 150mV tops and some for peaks for us classicals,for preamp level if a decent gain follows.

So,exactly were the famous ESS hump and the one shown here is.

Edit:Hopefully a couple of ESS's that I have measured with this problem can be relieved with DSD as it greatly reduces it for some reason,to the point of been decent.No EQ with that though.
Better avoid it.

 

[roog]

Serious question: how do we think that R2R DACs got their audiophile status?

 

[Sokel]

Serious question: how do we think that R2R DACs got their audiophile status?

Burr Brown 1704.

 

[JeremyFife]

Thanks for the review, always good to read.

How to assess this? A very good implementation of R2R (outdated technology?) or a good DAC that costs too much for the measured performance?

I went with the latter, but if I'd nailed my colours to R2R I'd be very happy.

 

[MaxwellsEq]

Serious question: how do we think that R2R DACs got their audiophile status?

R2R had a poor domestic audiophile reputation at the start. The earliest non-oversampling CD players were R2R and critics called them bright, shrill, gritty, glassy, shouty, lacking in bass etc.

Now, according to audiophiles, these bright, gritty DACs are smooth and "analogue". So, "audiophile status" is valueless.

 

[MaxwellsEq]

Thanks for the review, always good to read.

How to assess this? A very good implementation of R2R (outdated technology?) or a good DAC that costs too much for the measured performance?

I went with the latter, but if I'd nailed my colours to R2R I'd be very happy.

It's sort of in-between. R2R is not outdated - it's perfectly suited to the task but extraordinarily difficult to do well.

It costs a lot of money, but I don't think it's a good DAC. Intermodulation in the normal music range is simply too high for me. I'm not saying I could hear it, but why pay more for something measurably worse in the critical music sound level domain (between peak and noise floor).

 

[usersky]

Being this good actually defies the puropose of the device. Thanks for the review!

 

[Michal]

I wonder how the Laiv Harmony DAC would measure up. Maybe someone will send it to Amir for testing someday.

 

[NTTY]

The intermodulation graph demonstrates why not to buy this DAC. Why choose a product which is good at maximum signal and good at silence but poor in the middle (where music actually happens).

Because it's OK at max and at silence, it gets a higher SINAD score than it deserves. The test at -12dBFS that @NTTY does would be more useful here, since the current crop of chip DACs would stay in "Excellent" and this would probably drop out.

If Toping sends me one for testing, I’d be happy to report

R2R were all good at full scale indeed. Distorsion was increasing rapidly as we were lowering the digital output.

The IMD test (DIN, if I recall) of Amir partially shows the difference indeed. Distortion increases at around -6dBFS and becomes buried into noise at -53dB only, as Amir commented. So the view is distortion driven.

That’s why I also separate THD and Noise in my measurements at lower levels. I can hear a -100dBFS tone in -90dBFS dithered noise, so I like to look at these two.

I usually show FFT at 0dBFS and -6dBFS and a THD (only) sweep at -12dBFS, where we see a significant difference between R2R and 1bit.

All that said, very good performances here, obviously. I’d be happy to plug that DAC behind a CD player used as a transport to know more about it.

 

[Sokel]

Being this good actually defies the puropose of the device. Thanks for the review!

It's not that good when it fails the utmost more important metric,a flat FR.
It's actually strange.