R2R vs Delta Sigma DACs - same results?

[ohmywatt]

I don't have a pony in the race but my curiosity is tickled pink as I'm shopping for a dedicated/stand-alone DAC.

Heated debates are raging in forums pitching sound signatures, staging, depth, clarity etc. etc etc. ad infinitum against each other when comparing Delta Sigma designs, R2R designs and Delta Sigma vs R2R designs.

I struggle to understand how these different topologies/architectures, when brilliantly executed with quality parts, can result in the same outcome.

If a Delta Sigma DAC measured exactly the same as a R2R DAC and played through the same same system, level matched and all things equal, would they sound the same?

 

[voodooless]

I struggle to understand how these different topologies/architectures, when brilliantly executed with quality parts, can result in the same outcome.

Because they all have a common goal: output a near perfect reconstruction of the sound waves (as voltage) that are represented by the digital data.

 

[ohmywatt]

Because they all have a common goal: output a near perfect reconstruction of the sound waves that are represented by the digital data.

I appreciate your explanation. So the blanket statement, "all DACs sound the same", which is often encountered is not necessarily true, correct? Can I assume that exceptional execution of the design while incorporating quality parts can make a difference in a DACs presentation?

 

[voodooless]

The statement usually goes something like: all competently designed DACs sound the same.

Quality parts? What are those? If it’s audible transparent, it’s audibly transparent, no matter what parts were used. Engineering is much more important. You can use “quality” parts and still make a crappy product.

 

[Beave]

The statement usually goes something like: all competently designed DACs sound the same.

Quality parts? What are those? If it’s audible transparent, it’s audibly transparent, no matter what parts were used. Engineering is much more important. You can use “quality” parts and still make a crappy product.

Maybe this? "All competently designed DACs sound the same when listened to with controls in place (ie, level-matched and blinded listening)."

 

[voodooless]

Maybe this? "All competently designed DACs sound the same when listened to with controls in place (ie, level-matched and blinded listening)."

They also sound the same without controls

 

[ohmywatt]

The statement usually goes something like: all competently designed DACs sound the same.

Quality parts? What are those? If it’s audible transparent, it’s audibly transparent, no matter what parts were used.

I assume the end result/finished component is a sum of its parts and that individual parts are not all created the same. But to your statement, if the device is audibly transparent it probably does not matter what parts were used. This mindset will help me avoid falling victim to all the marketing gibberish in my search for a DAC.

 

[voodooless]

Select a DAC based on validated performance data, feature set, looks and budgetary constraints.

 

[JustAnandaDourEyedDude]

All competent ASR members sound the same about the sound of DACs

 

[pma]

If a Delta Sigma DAC measured exactly the same as a R2R DAC

It is close to impossible to get as good parameters from the R2R DAC as from the SOTA sigma-delta DAC. Because of the different circuit principle.

 

[Snoopy]

It is close to impossible to get as good parameters from the R2R DAC as from the SOTA sigma-delta DAC. Because of the different circuit principle.

A Holo Cyan 2 is not crazy expensive and it measured pretty good here on ASR. Also a great dac for someone that uses software to upsample anyway.

 

[Gibsonian]

I appreciate your explanation. So the blanket statement, "all DACs sound the same", which is often encountered is not necessarily true, correct? Can I assume that exceptional execution of the design while incorporating quality parts can make a difference in a DACs presentation?

Correct. They don’t all sound or measure the same

 

[dday84]

I would have said that I subjectively prefer the sound of R2R dacs in general vs DS. However, what I have eventually concluded though is that I just happen to like the sound when there is some additional added harmonic distortion. I think many R2R dacs have increased distortion levels vs DS. I have a good measuring DS Dac. When I use Foobar2000 I have a VST plugin for it that allows me to add harmonic distortion (F2 through F8) and set the levels for each of those. I then send this to a Wiim Pro that is connected to my DS Dac that feeds an input on my stereo preamp.

Without using a bunch of cliche terms, I do find the sound more pleasing than without it. The plugin I use is Pkharmonic. I add some harmonic distortion at F2, F3, and F4 (F2 is highest level I set). I find if I go too high with distortion than the bass sounds too loose and not defined, but anyone can experiment with this tool and draw their own conclusions.

I think this harmonic distortion is also why I have also loved vinyl my whole life.

With Foobar and this plugin I am in control of the distortion levels, and it is not some random distortion profile tied to the hardware itself.

 

[Purité Audio]

I grew up with vinyl, but instantly switched to CD and not just for the convenience.
Keith

 

[Jazigo]

Hi everyone!

Is there a case for R2R DACs being the better option for 16bit content?

Current oversampling DACs have the issue with intersample overs 0db, so one have to adjust the digital volume down to -6db.
The noise of 16bit audio is a best -98.7db.
This means that the SNR is at best 92.7db with a oversampling DAC, but we could get the full 98.7db with a R2R DAC.

 

[JSmith]

Heated debates are raging in forums pitching sound signatures, staging, depth, clarity etc. etc etc. ad infinitum against each other when comparing Delta Sigma designs, R2R designs and Delta Sigma vs R2R designs.

That's all subjective nonsense... doesn't not correlate to measurements, logic or blind comparisons. Don't worry about R2R... just get a normal DAC that suits your needs and move on to other parts of the system and listening to music, not the gear.


JSmith

 

[solderdude]

Hi everyone!

Is there a case for R2R DACs being the better option for 16bit content?

Current oversampling DACs have the issue with intersample overs 0db, so one have to adjust the digital volume down to -6db.
The noise of 16bit audio is a best -98.7db.
This means that the SNR is at best 92.7db with a oversampling DAC, but we could get the full 98.7db with a R2R DAC.

We need to differentiate between 'R2R converters' which can also be used at higher sample rates or over-sample anyway and filterless (NOS) R2R.

Filterless 44.1 and 48kHz files indeed can be audible distinguishable with filterless DACs and even with simulated filterless DS DACs for folks with young ears.
This is because of the stair-steps (which create a kind of treble roll-off) and is not compliant to the sampling theorem. Add the HUGE amount of unwanted HF signals that may (but doesn't have to) even 'fold back' into the audible domain depending on the situation.

Ironically, what most people may not realize, is that the actual output stage of a Delta Sigma DAC also is R2R (or something to a similar effect) but only 4 to 7 bits or so.
This is much easier to make accurately than the difference between the MSB and LSB of a 16-20 bit R2R(ladder or other type) of converter.
It just operates on a MUCH higher frequency and thus does not do the 'sample and hold' thing (which is incorrect by nature anyway).

Sure, the DS upsampling process, with its shaped noise, which is NOT the same as the noise generated by multibit R2R in spectrum. Differs in numbers but that noise is shaped and 'shifted' above the audible range and... try to find transducers (and above all ears) that detect that.

Secondly... try to find a recording that is made using microphones that actually has a S/N ratio (in the audible band) that even comes close to 92.7dB

So no ... there is nothing to be said for filterless DAC operation (which often is meant by NOS R2R)and when oversampled (and thus filtered) there is no benefit between R2R and DS except perhaps HF noise presence.

 

[Jazigo]

We need to differentiate between 'R2R converters' which can also be used at higher sample rates or over-sample anyway and filterless (NOS) R2R.

Filterless 44.1 and 48kHz files indeed can be audible distinguishable with filterless DACs and even with simulated filterless DS DACs for folks with young ears.
This is because of the stair-steps (which create a kind of treble roll-off) and is not compliant to the sampling theorem. Add the HUGE amount of unwanted HF signals that may (but doesn't have to) even 'fold back' into the audible domain depending on the situation.

Ironically, what most people may not realize, is that the actual output stage of a Delta Sigma DAC also is R2R (or something to a similar effect) but only 4 to 7 bits or so.
This is much easier to make accurately than the difference between the MSB and LSB of a 16-20 bit R2R(ladder or other type) of converter.
It just operates on a MUCH higher frequency and thus does not do the 'sample and hold' thing (which is incorrect by nature anyway).

Sure, the DS upsampling process, with its shaped noise, which is NOT the same as the noise generated by multibit R2R in spectrum. Differs in numbers but that noise is shaped and 'shifted' above the audible range and... try to find transducers (and above all ears) that detect that.

Secondly... try to find a recording that is made using microphones that actually has a S/N ratio (in the audible band) that even comes close to 92.7dB

So no ... there is nothing to be said for filterless DAC operation (which often is meant by NOS R2R)and when oversampled (and thus filtered) there is no benefit between R2R and DS except perhaps HF noise presence.

I realize that we are splitting hairs here, but I think that technically, the R2R DAC can have a higher SNR without intersample over 0db (for 16 bit pcm data).

 

[solderdude]

It's like saying that technically a DAC with SINAD 125 is better than SINAD 119 in technical signal fidelity but does it matter when the S/N ratio of any recording is magnitudes worse and that SINAD difference is dwarfed by noise in any recording ?

 

[Jazigo]

It's like saying that technically a DAC with SINAD 125 is better than SINAD 119 in technical signal fidelity but does it matter when the S/N ratio of any recording is magnitudes worse and that SINAD difference is dwarfed by noise in any recording ?

Yes, technically.