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Another stupiid question - delta sigma


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Is delta-sigma that is "frowned on" but used by many large manufacturers of dacs, is that what is used for hardware upsampling, or is it used for something else?

 

If so, If i am content without upsampling or using software upsampling, then i should care less about delta-sigma?

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Delta-sigma modulation, also termed SDM, refers to the way the DAC converts digital to analog. This is how DSD works. The point being that all of these DACs internally convert to something like DSD. All of them that accept PCM.

 

The alternative type of DAC that accepts PCM is called R2R or ladder where a network of hopefully very precise resistors is used to convert to analog. The difficulty is that it's very hard to get >18bits resolution with normal resistor precision, and DAC chips like the 1704 are no longer made.

 

If you are using software upsampling with a delta sigma DAC it makes the most sense also to have the software convert to DSD i.e. Do the delta - sigma, then the DAC doesn't need to do any conversion.

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Delta-sigma modulation, also termed SDM, refers to the way the DAC converts digital to analog. This is how DSD works. The point being that all of these DACs internally convert to something like DSD. All of them that accept PCM.

 

The alternative type of DAC that accepts PCM is called R2R or ladder where a network of hopefully very precise resistors is used to convert to analog. The difficulty is that it's very hard to get >18bits resolution with normal resistor precision, and DAC chips like the 1704 are no longer made.

 

If you are using software upsampling with a delta sigma DAC it makes the most sense also to have the software convert to DSD i.e. Do the delta - sigma, then the DAC doesn't need to do any conversion.

 

I don't think you can really make a blanket statement about all delta sigma DACs internally converting to DSD, for instance the Sabre ESS DACs that I know of do not do this. They are more like a "hybrid" in that sense.

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I don't think you can really make a blanket statement about all delta sigma DACs internally converting to DSD, for instance the Sabre ESS DACs that I know of do not do this. They are more like a "hybrid" in that sense.

 

I said "something like DSD" and I think folks want an easily understandable answer.

 

The point being that either the chip performs the SDM or it's done in software.

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I don't think you can really make a blanket statement about all delta sigma DACs internally converting to DSD, for instance the Sabre ESS DACs that I know of do not do this. They are more like a "hybrid" in that sense.

 

But the Sabre DAC is still powered by 1-bit DACs internally, and is of course also a delta sigma DAC.

 

Take note that today's DSD DACs are either 1-bit or few-bit delta-sigma DACs. And so are majority of PCM DACs.

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But the Sabre DAC is still powered by 1-bit DACs internally, and is of course also a delta sigma DAC.

 

Take note that today's DSD DACs are either 1-bit or few-bit delta-sigma DACs. And so are majority of PCM DACs.

 

I'm not disputing that it's not delta sigma. But can you link me to where in their white papers it says it is doing 1-bit computation? I'm using a DAC a friend designed around it (I just looked on ESS site and I think he is using a slightly older version?) and from everything he has told me it is multibit operation.

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^^^ thanks for all the input...i will read with more intensity and see if i can find understanding...to clarify my question further, lets use real examples...if i use jriver software for example and upsample pcm to 256DSD, then is the "delta-sigma" ore even "r2r" dac chip (or whatever schiit uses) even matter?...if it doesn't do any upsampling, then that circuitry doesn't even matter?

 

I will study responses more later, my wife is tugging at my arm to take her out to eat...ack

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I said "something like DSD" and I think folks want an easily understandable answer.

 

The point being that either the chip performs the SDM or it's done in software.

Yes, but the internal sdm is multi-bit (typically 5 or 6 bits), and there is no way to input this format directly. Thus you're stuck with 1-bit DSD which has worse noise characteristics. The only reason it might end up better is that superior upsampling beyond 8x is possible instead of the sample and hold usually used internally.

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Yes, but the internal sdm is multi-bit (typically 5 or 6 bits), and there is no way to input this format directly. Thus you're stuck with 1-bit DSD which has worse noise characteristics. The only reason it might end up better is that superior upsampling beyond 8x is possible instead of the sample and hold usually used internally.

 

At 128FS+ DSD rates, DSD noise characteristics are already very good, as you can see on the measurements below.

 

Squarewaves from DACs - Blogs - Computer Audiophile

 

IIRC, Miska is able to achieve 32-bit performance with DSD256 modulators...

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I'm not disputing that it's not delta sigma. But can you link me to where in their white papers it says it is doing 1-bit computation? I'm using a DAC a friend designed around it (I just looked on ESS site and I think he is using a slightly older version?) and from everything he has told me it is multibit operation.

 

It is not multibit in PCM sense, but DSD sense, as it's using many 1-bit DSD DACs for conversion (64 of them IIRC). It's one possible architecture found in DSD DACs these days, and you'll find different variations of it in different DSD DACs.

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It is not multibit in PCM sense, but DSD sense, as it's using many 1-bit DSD DACs for conversion (64 of them IIRC). It's one possible architecture found in DSD DACs these days, and you'll find different variations of it in different DSD DACs.

 

Well I never said anything about PCM, just it is not true DSD which is 1 bit and whatever sample rate attached to it. Again can you point to me where in any of their white papers they say they use multiple 1-bit DSD DACs for conversion? I've spoke to my friend and have some recollection of the big multibit DSD thread and what you're saying doesn't sound familiar (though I'm willing to accept I could be wrong).

 

Further why I don't think the ESS is using run of the mill delta sigma processing is that native PCM sounds better than software DSD upsampling to me and everyone else in our listening tests. For frame of reference the closest thing this DAC is equivalent to is probably Merging NADAC, though they probably have the superior input system with Ravenna.

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^^^ thanks for all the input...i will read with more intensity and see if i can find understanding...to clarify my question further, lets use real examples...if i use jriver software for example and upsample pcm to 256DSD, then is the "delta-sigma" ore even "r2r" dac chip (or whatever schiit uses) even matter?...if it doesn't do any upsampling, then that circuitry doesn't even matter?

 

I will study responses more later, my wife is tugging at my arm to take her out to eat...ack

 

It's more than that. If you up convert PCM to DSD256, then an R2R DAC won't accept the signal, or would need to convert it back to PCM in order to use it. OTOH a delta-sigma chip would probably either use it without further conversion, or else convert single bit to multibit SDM if it wants to do that

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Well I never said anything about PCM, just it is not true DSD which is 1 bit and whatever sample rate attached to it. Again can you point to me where in any of their white papers they say they use multiple 1-bit DSD DACs for conversion? I've spoke to my friend and have some recollection of the big multibit DSD thread and what you're saying doesn't sound familiar (though I'm willing to accept I could be wrong).

 

Well, it's popular knowledge at this point that the ESS Sabre chips are using multiple 1-bit DACs for D/A conversion, though you won't perhaps find it mentioned anywhere on the ESS website since they keep the detail information about their DAC architecture close to their chest. Now, as for designing a DSD DAC, how many 1-bit DSD DACs you're going to use for D/A conversion is entirely up to the designer. There's no document that would specify that, and because of that there are DSD DACs with different architectures. As I said, most DSD DACs are either 1-bit or few-bit delta sigma designs.

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... Now, as for designing a DSD DAC, how many 1-bit DSD DACs you're going to use for D/A conversion is entirely up to the designer. There's no document that would specify that, and because of that there are DSD DACs with different architectures. As I said, most DSD DACs are either 1-bit or few-bit delta sigma designs.

 

Yes, and no matter what you do, you still have to filter! Just as with PCM, the filter techniques generally have greater impact on SQ than the D/A architecture.

The shift-register FIR as used by both Burr-Brown and (more discreetly) by Miska's DSC-1 strikes me to be one of the cleanest ways to handle DSD data.

Unless you are into the hairy, just throw an RC network or transformer at it for LPF. Just keep the scope away from those designs. ;)

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I wasn't able to wean the answer to my question from above, although it is probably there, but i just realized from reading this

 

Why High Resolution Audio? FLAC or DSD | DSD-Guide.com

 

That delta-sigma is what is required for DSD, so anyone that is frowning on delta-sigma is simply frowning on DSD...so i am assuming now that everyone that says "blah delta sigma" is simply a pcm only type of person. I don't know if some dacs implement both delta sigma and some other modulation, but i personally would prefer a dac that did support DSD (delta-sigma), so I am no longer going to worry if my dac is delta-sigma or not, as I only want a dac that supports delta-sigma and possibly something else.

 

On the other hand, I am going to suggest that i prefer using software vs hardwre to do any upsampling, so if that delta-sigma is not needed in the dac if i upsample using software (e.g. hqplayer, jriver, or audiogate), or if i start with native dsd, then that is fine too. I guess i still have the same question...

 

YES OR NO, if i send a native dsd stream to a dac, does the dac still need delta-sigma to convert to analog?

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I wasn't able to wean the answer to my question from above, although it is probably there, but i just realized from reading this

 

Why High Resolution Audio? FLAC or DSD | DSD-Guide.com

 

That delta-sigma is what is required for DSD, so anyone that is frowning on delta-sigma is simply frowning on DSD...so i am assuming now that everyone that says "blah delta sigma" is simply a pcm only type of person. I don't know if some dacs implement both delta sigma and some other modulation, but i personally would prefer a dac that did support DSD (delta-sigma), so I am no longer going to worry if my dac is delta-sigma or not, as I only want a dac that supports delta-sigma and possibly something else.

 

On the other hand, I am going to suggest that i prefer using software vs hardwre to do any upsampling, so if that delta-sigma is not needed in the dac if i upsample using software (e.g. hqplayer, jriver, or audiogate), or if i start with native dsd, then that is fine too. I guess i still have the same question...

 

YES OR NO, if i send a native dsd stream to a dac, does the dac still need delta-sigma to convert to analog?

Answer this for me in order to understand what you are trying to get from this.

 

If the answer is yes what does that mean for you, and what will you do as a result?

 

If the answer is no what does that mean for you, and what will you do differently?

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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Answer this for me in order to understand what you are trying to get from this.

 

If the answer is yes what does that mean for you, and what will you do as a result?

 

If the answer is no what does that mean for you, and what will you do differently?

 

 

Several times when i am considering a new dac, lots of times i see a response like (blah delta-sigma), and I don't know the engineering of dacs, but if it was accepted that "delta-sigma" is a cheap poor design, then I would want to look for a dac that didn't have a cheap or bad design. I was thinking that maybe it was known that delta-sigma dacs are cheaper and inferior to better technologies. But if now, my understanding is that all DSD dacs probably have some type of delta-sigma design, then i will not let that influence my buying decsion, and in actuality, i will more than likely ONLY want a dac with delta-sigma circuitry and realize that the one or two that say "blah, delta-sigma" are simply saying they don't like DSD, and i can ignore those responses.

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Is delta-sigma that is "frowned on" but used by many large manufacturers of dacs, is that what is used for hardware upsampling, or is it used for something else?

 

If so, If i am content without upsampling or using software upsampling, then i should care less about delta-sigma?

 

 

 

My opinion. You have brand new Schiit DAC and TEAC DAC at home. Stop worrying about the technology, listen to the DACs, and either keep both or return one (or both) according to how they sound to your ears.

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I wasn't able to wean the answer to my question from above, although it is probably there, but i just realized from reading this

 

Why High Resolution Audio? FLAC or DSD | DSD-Guide.com

 

That delta-sigma is what is required for DSD, so anyone that is frowning on delta-sigma is simply frowning on DSD...so i am assuming now that everyone that says "blah delta sigma" is simply a pcm only type of person. I don't know if some dacs implement both delta sigma and some other modulation, but i personally would prefer a dac that did support DSD (delta-sigma), so I am no longer going to worry if my dac is delta-sigma or not, as I only want a dac that supports delta-sigma and possibly something else.

 

On the other hand, I am going to suggest that i prefer using software vs hardwre to do any upsampling, so if that delta-sigma is not needed in the dac if i upsample using software (e.g. hqplayer, jriver, or audiogate), or if i start with native dsd, then that is fine too. I guess i still have the same question...

 

YES OR NO, if i send a native dsd stream to a dac, does the dac still need delta-sigma to convert to analog?

 

Depends on the DAC. Answer can be yes or no.

 

Oops, not what you wanted to hear....

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My opinion. You have brand new Schiit DAC and TEAC DAC at home. Stop worrying about the technology, listen to the DACs, and either keep both or return one (or both) according to how they sound to your ears.

+1.

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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My opinion. You have brand new Schiit DAC and TEAC DAC at home. Stop worrying about the technology, listen to the DACs, and either keep both or return one (or both) according to how they sound to your ears.

 

its not a new schiit dac, and i will/have listened to both..i will likely get something else some time..as i am always buying trying new things...its one of my many hobbies.

 

I am just trying to educate myself as to what those people are saying that say "blah sigma-delta"...

 

and i believe i have, that more than likely they are just "pcm only types"...

 

i accomplished what i set out to accomplish...thanks for your valuable input.

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