Topping Centaurus R2R DAC Review

[Dougey_Jones]

Why would it be?

Because delta sigma DAC's by their very nature are always approximating the waveform (albeit very accurately these days) and resistor ladders (depending on their design limits) are able to fully resolve the waveform instead of just approximating it.

 

[VientoB]

Because delta sigma DAC's by their very nature are always approximating the waveform (albeit very accurately these days) and resistor ladders (depending on their design limits) are able to fully resolve the waveform instead of just approximating it.

I think the distortion tells you they are resolving it worse than DS DACs are approximating it.

 

[Sokel]

All K11 R2R outputs have max 72dB SINAD:
View attachment 414431

R2R distortion is the limiting factor.

I've been generous,didn't include the 3rd decimal

 

[Purité Audio]

No afraid not, a really well engineered R2R design such as this Topping will almost certainly be indistinguishable from any other well engineered sigma delta design, you would have to look at a really poorly engineered R2R to hear any difference and that difference would not be an improvement.
Keith

 

[VientoB]

No afraid not, a really well engineered R2R design such as this Topping will almost certainly be indistinguishable from any other well engineered sigma delta design, you would have to look at a really poorly engineered R2R to hear any difference and that difference would not be an improvement.
Keith

I dont think we're talking about hearing the difference here.

 

[oleg87]

Because delta sigma DAC's by their very nature are always approximating the waveform (albeit very accurately these days) and resistor ladders (depending on their design limits) are able to fully resolve the waveform instead of just approximating it.

Well, that is not true. R2Rs are also approximating it, usually to a much worse degree, because of the finite precision/stability of components.

 

[Sokel]

I think the distortion tells you they are resolving it worse than DS DACs are approximating it.

He's talking about the sampling probably.
It's only one occasion (Holo Cyan2) where I saw measured astonishing performance,and that is with DSD,not PCM.

 

[unpluggged]

resistor ladders (depending on their design limits) are able to fully resolve the waveform instead of just approximating it.

??????????????

 

[Dougey_Jones]

??????????????

Courtesy of ChatGPT

Why Resistor Ladders Excel at Lower Bit Depths​

1. Direct Conversion:
   Resistor ladder DACs perform a true binary-to-analog conversion, meaning the analog output is determined purely by the input bits and the precision of the resistors. There’s no additional oversampling, noise shaping, or interpolation involved, as found in delta-sigma DACs.
2. Precision:
   • For 16-bit audio, the resistor ladder must resolve 2162^{16}216 discrete voltage steps (65,536 levels). This requires resistors with very tight tolerances—on the order of 0.01% or better—to ensure linearity and accuracy.
   • If the resistors are perfectly matched and the DAC's output stage is clean, the conversion is inherently accurate for signals within the design range.

 

[unpluggged]

Courtesy of ChatGPT

There’s no additional oversampling, noise shaping, or interpolation involved, as found in delta-sigma DACs.

Right. So this is how the waveform looks in this case:

 

[VientoB]

Courtesy of ChatGPT

Why Resistor Ladders Excel at Lower Bit Depths​

1. Direct Conversion:
   Resistor ladder DACs perform a true binary-to-analog conversion, meaning the analog output is determined purely by the input bits and the precision of the resistors. There’s no additional oversampling, noise shaping, or interpolation involved, as found in delta-sigma DACs.
2. Precision:
   • For 16-bit audio, the resistor ladder must resolve 2162^{16}216 discrete voltage steps (65,536 levels). This requires resistors with very tight tolerances—on the order of 0.01% or better—to ensure linearity and accuracy.
   • If the resistors are perfectly matched and the DAC's output stage is clean, the conversion is inherently accurate for signals within the design range.

The resisters are never perfectly matched.

 

[Purité Audio]

Essentially there is nothing special about R2R.
Keith

 

[oleg87]

Well, you know ChatGPT just ingests whatever audiophile marketing gibberish it can trawl through on the internet?

Courtesy of ChatGPT

Why Resistor Ladders Excel at Lower Bit Depths​

1. Direct Conversion:
   Resistor ladder DACs perform a true binary-to-analog conversion, meaning the analog output is determined purely by the input bits and the precision of the resistors. There’s no additional oversampling, noise shaping, or interpolation involved, as found in delta-sigma DACs.
2. Precision:
   • For 16-bit audio, the resistor ladder must resolve 2162^{16}216 discrete voltage steps (65,536 levels). This requires resistors with very tight tolerances—on the order of 0.01% or better—to ensure linearity and accuracy.
   • If the resistors are perfectly matched and the DAC's output stage is clean, the conversion is inherently accurate for signals within the design range.

The goal of digital-analog conversion is not to accurately reproduce a signal that looks like a zero-order hold sequence of the input codes, but to make the closest reconstruction of the sampled signal according to the sampling theorem. Oversampling, noise shaping, etc, are ways to do this more accurately. The chief limitation of delta-sigma converters compared to other methods is that your maximum sampling rate is relatively limited. For audio applications (and human-audible signals are glacially slow, in electronics terms), this is perfectly fine.

 

[antcollinet]

Courtesy of ChatGPT

Why Resistor Ladders Excel at Lower Bit Depths​

1. Direct Conversion:
   Resistor ladder DACs perform a true binary-to-analog conversion, meaning the analog output is determined purely by the input bits and the precision of the resistors. There’s no additional oversampling, noise shaping, or interpolation involved, as found in delta-sigma DACs.
2. Precision:
   • For 16-bit audio, the resistor ladder must resolve 2162^{16}216 discrete voltage steps (65,536 levels). This requires resistors with very tight tolerances—on the order of 0.01% or better—to ensure linearity and accuracy.
   • If the resistors are perfectly matched and the DAC's output stage is clean, the conversion is inherently accurate for signals within the design range.

I wish people would stop trying to use Arbitrary Incomprehension generators as research tools.

And as usual - also in this case - it has just regurgitated audiophile folklore.

 

[MaxwellsEq]

Courtesy of ChatGPT

Why Resistor Ladders Excel at Lower Bit Depths​

1. Direct Conversion:
   Resistor ladder DACs perform a true binary-to-analog conversion, meaning the analog output is determined purely by the input bits and the precision of the resistors. There’s no additional oversampling, noise shaping, or interpolation involved, as found in delta-sigma DACs.
2. Precision:
   • For 16-bit audio, the resistor ladder must resolve 2162^{16}216 discrete voltage steps (65,536 levels). This requires resistors with very tight tolerances—on the order of 0.01% or better—to ensure linearity and accuracy.
   • If the resistors are perfectly matched and the DAC's output stage is clean, the conversion is inherently accurate for signals within the design range.

ChatGPT is trained on nonsense on the Internet.

 

[MaxwellsEq]

Because delta sigma DAC's by their very nature are always approximating the waveform (albeit very accurately these days) and resistor ladders (depending on their design limits) are able to fully resolve the waveform instead of just approximating it.

You will need to provide references for this (not made-up nonsense from ChatGPT)

 

[MaxwellsEq]

Surprisingly controversial, this review!

I've a confession to make - the first CD player I used had a similar DAC to this technology. And I'm an engineer!

 

[masterhw]

I've a confession to make - the first CD player I used had a similar DAC to this technology. And I'm an engineer!

But I'd bet you didn't spend a penny more for it having this architecture. If it performs fine, then this is what the purchase is made on. I think the only offense to seeing R2R again is that this product (Centaurus) performs well in spite of the architecture, and perhaps the resources could've done more good on more fundamentally sound approaches (no pun intended). But if it performs well, ultimately any dissent is academic.

 

[VientoB]

Surprisingly controversial, this review!

I've a confession to make - the first CD player I used had a similar DAC to this technology. And I'm an engineer!

Was it an old CD player from the 80s?

 

[Dougey_Jones]

But I'd bet you didn't spend a penny more for it having this architecture. If it performs fine, then this is what the purchase is made on. I think the only offense to seeing R2R again is that this product (Centaurus) performs well in spite of the architecture, and perhaps the resources could've done more good on more fundamentally sound approaches (no pun intended). But if it performs well, ultimately any dissent is academic.

ASR operates heavily on groupthink. Some things are considered anathema and R2R is one of them, even if you acknowledge the limitations as I have in this thread. I limited my inquiry strictly to 16/44 redbook CD, which good R2R implementations can very accurately decode, without any of the extra tomfoolery employed in DS implementations and look at the reaction it provoked.

I don't even own an R2R dac, I'm just trying to understand the potential strengths and getting this much pushback. Also, the ChatGPT hate is stunningly laughable. It easily passed the Harvard Medical boards, Harvard Law Bar exam and is capable of writing code surely better than 99% of ASR contributors, welcome to reality.

"R-2R DACs perform direct conversion from digital to analog by using a network of resistors to create discrete voltage steps corresponding to the digital input. This simplicity is a significant advantage in terms of signal purity, as there is no intermediate signal processing like in delta-sigma DACs.

• R-2R DAC: The DAC directly outputs the analog signal without any digital modulation, oversampling, or noise-shaping.
• Delta-Sigma DAC: Involves oversampling (usually 64x or higher), noise shaping, and the use of a modulator to convert the input signal to a high-frequency bitstream that is then filtered to produce the final analog signal.

References:

In the book "Data Conversion Handbook" by Walt Kester (Analog Devices), the author explains how oversampling in delta-sigma DACs leads to the reduction of quantization noise but can also introduce distortion and intermodulation products if not well-managed. In contrast, R-2R DACs avoid these issues by directly converting the binary input to an analog voltage.

The paper "Design and Optimization of DACs for High-Speed Data Conversion" published in the IEEE Transactions on Circuits and Systems discusses how the speed of a DAC architecture like R-2R is often superior to delta-sigma designs, particularly in systems where latency is a priority.

The paper "Performance Analysis of R-2R Ladder DACs" (IEEE Transactions on Circuits and Systems) highlights that R-2R DACs, with careful resistor matching, are able to provide high linearity and low distortion, making them ideal for systems where signal purity is prioritized.