Jump to content
The Computer Audiophile

Audirvana Plus 3 for Windows (Official Thread)

Rate this topic

Recommended Posts

I started using the mac version many years ago, and DSD64 => DSD 256 worked from the start.

 

@damien78

Maybe you can shed some light?

Main question is: can A+ for Windows upsample DSD64 to DSD256 and if yes, how?

Share this post


Link to post
Share on other sites

By the way, I will gently disagree with whether upsampling DSD is essential, since conversion to PCM is necessary as an intermediate step. I would tend to purchase PCM versions (if the same mastering), since with DSD to DSD conversion the final conversion will be from the intermediate PCM anyway.

Share this post


Link to post
Share on other sites
1 minute ago, bodiebill said:

 

I started using the mac version many years ago, and DSD64 => DSD 256 worked from the start.

 

 

I am virtually certain this was not the case years ago (DSD to DSD conversion on the Mac). I can always be wrong of course, but I don't think so....

Share this post


Link to post
Share on other sites

You maybe right about that.

 

I have no preference for either DSD or PCM but I do know that my Lampizator Lite 7's DSD chain is way better than its PCM chain. And DSD64 upsampled (by either Audirvana mac or HQPlayer) to DSD256 sounds considerably better than the original DSD64.

 

On the other hand, PCM sounds absolutely gorgeous with my Audio Aéro DAC. It can compete with Lampizator DSD, but with a different sound signature (I call it 'creamy' but not in a bad way).

 

I was not aware that A+ (and HQPlayer?) upsample DSD => PCM => DSD.

Share this post


Link to post
Share on other sites
51 minutes ago, bodiebill said:

I was not aware that A+ (and HQPlayer?) upsample DSD => PCM => DSD.

 

It's not possible to upsample 1-bit format (DSD) directly.

Share this post


Link to post
Share on other sites
3 hours ago, Jud said:

 

It's not possible to upsample 1-bit format (DSD) directly.

You can get around that by converting it to multibit DSD.

Share this post


Link to post
Share on other sites
1 hour ago, firedog said:

You can get around that by converting it to multibit DSD.

 

DSD, strictly defined, is 1-bit.  It's PDM or PWM, not PCM.  Anything with more than 1 bit has a PCM component.

Share this post


Link to post
Share on other sites

Multi-level SDM is not the same as PCM. (And if you want, you can also upsample 1-bit DSD as is.)

 

Note that multi-level SDM can typically have for example 3 or 5 levels that doesn't match with any number of two's complement PCM bits. For example modulators in TI DAC chips have 5-level output, that is log2(5) = 2.3219 two's complement bits. Advantage of  multi-level SDM compared to PCM is that for all values except 0 and maximum, multi-level SDM has more than one representation for the same value. This is one property that multi-level SDM DAC chips extensively utilize. Same feature allows also good quality bit-perfect DSD conversion when used correctly.

 

6 hours ago, jamesg11 said:

As with what Miska does in HQP?

 

HQPlayer has two modulator variants, one that eats PCM inputs and another that eats SDM inputs (2 - 256 level). To be exact, there are two totally separate DSP engines, one for PCM outputs and another one for SDM outputs since these work in a different way. The SDM input one can remodulate directly from one SDM rate and number of levels to another SDM rate and number of levels. So for example rate is converted directly from 2.8 MHz to 11.3 MHz, without any intermediate rate. The modulator itself has gain property which allows adjusting volume as part of the process. You can also bake other kind of things into the modulator.

 

Also things like convolution are processed at the native rate, so for example if you do convolution for DSD256, it is processed at 11.3 MHz sampling rate.

 

5 hours ago, Jud said:

DSD, strictly defined, is 1-bit.  It's PDM or PWM, not PCM.  Anything with more than 1 bit has a PCM component.

 

So you define 2-level SDM very strictly and PCM very loosely. :D If you are that loose, you can also say that DSD is just 1-bit PCM. Much simpler to call everything PCM! It would be better to be equally strict on both.

 

Equally strictly defined, PCM is two's complement (binary encoded) integer representation. So either DSD is also PCM, or HQPlayer doesn't convert to PCM.

 

 

Share this post


Link to post
Share on other sites
5 hours ago, Jud said:

 

DSD, strictly defined, is 1-bit.  It's PDM or PWM, not PCM.  Anything with more than 1 bit has a PCM component.

And many in the field would say that's irrelevant. DSD is more of a marketing term of Sony's, than a relevant technical term. See Miska's post.

Share this post


Link to post
Share on other sites

Interesting stuff! Especially the view that DSD can be seen as a 1-bit instance of PCM. Maybe that could make the DSD vs PCM discussion less black and white. After all, "what's in a name?". In the meantime, with much respect for the technical artistry to make this all work, I continue to trust my ears... 🙂

Share this post


Link to post
Share on other sites
5 hours ago, Miska said:

Multi-level SDM is not the same as PCM. (And if you want, you can also upsample 1-bit DSD as is.)

 

Note that multi-level SDM can typically have for example 3 or 5 levels that doesn't match with any number of two's complement PCM bits. For example modulators in TI DAC chips have 5-level output, that is log2(5) = 2.3219 two's complement bits. Advantage of  multi-level SDM compared to PCM is that for all values except 0 and maximum, multi-level SDM has more than one representation for the same value. This is one property that multi-level SDM DAC chips extensively utilize. Same feature allows also good quality bit-perfect DSD conversion when used correctly.

 

 

HQPlayer has two modulator variants, one that eats PCM inputs and another that eats SDM inputs (2 - 256 level). To be exact, there are two totally separate DSP engines, one for PCM outputs and another one for SDM outputs since these work in a different way. The SDM input one can remodulate directly from one SDM rate and number of levels to another SDM rate and number of levels. So for example rate is converted directly from 2.8 MHz to 11.3 MHz, without any intermediate rate. The modulator itself has gain property which allows adjusting volume as part of the process. You can also bake other kind of things into the modulator.

 

Also things like convolution are processed at the native rate, so for example if you do convolution for DSD256, it is processed at 11.3 MHz sampling rate.

 

 

So you define 2-level SDM very strictly and PCM very loosely. :D If you are that loose, you can also say that DSD is just 1-bit PCM. Much simpler to call everything PCM! It would be better to be equally strict on both.

 

Equally strictly defined, PCM is two's complement (binary encoded) integer representation. So either DSD is also PCM, or HQPlayer doesn't convert to PCM.

 

I thought I recalled something different from a conversation between you and mansr here on the forums, but I could be misremembering.

 

My notion of DSD is that it's 1-bit, with values obtained through pulse width/density (more 1s for higher values, more 0s for lower values), like adjustments to a steering wheel, whereas PCM "words" have assigned values like points on a graph or map, and bits within the "word" have different values depending on position, so 010 and 100 are different.

Share this post


Link to post
Share on other sites
41 minutes ago, Jud said:

My notion of DSD is that it's 1-bit, with values obtained through pulse width/density (more 1s for higher values, more 0s for lower values), like adjustments to a steering wheel, whereas PCM "words" have assigned values like points on a graph or map, and bits within the "word" have different values depending on position, so 010 and 100 are different.

 

There can be smaller and larger pulses. Good example being DSC-1 DAC where after each bit the conversion output can have one of the 33 possible values. Yet it is totally bit-perfect DSD converter.

 

And you can have for example 1-bit word with values 0 and 1. And you can have 32-bit word with values 0 and 1. Both have same meaning. Or you can have letter 'a' and 'b' instead. So it won't make any difference. So in your generalization, then also DSD would be PCM.

 

41 minutes ago, Jud said:

bits within the "word" have different values depending on position, so 010 and 100 are different

 

That is not the case for multi-level SDM. You can also interchangeably transform between the two representations, to limited extent.

 

41 minutes ago, Jud said:

I thought I recalled something different from a conversation between you and mansr here on the forums, but I could be misremembering.

 

Can you give a pointer?

Share this post


Link to post
Share on other sites
10 minutes ago, Miska said:

Can you give a pointer?

 

Wish I could! I would have to search, and if I am misremembering, I wouldn't find anything.  :D 

 

The Wikipedia article gives a nice outline of the picture I have in my head (in the "DSD technique" section), as well as saying things are really more complex than that, especially these days.  https://en.wikipedia.org/wiki/Direct_Stream_Digital

 

Share this post


Link to post
Share on other sites
6 minutes ago, Jud said:

 

Wish I could! I would have to search, and if I am misremembering, I wouldn't find anything.  :D 

 

The Wikipedia article gives a nice outline of the picture I have in my head (in the "DSD technique" section), as well as saying things are really more complex than that, especially these days.  https://en.wikipedia.org/wiki/Direct_Stream_Digital

 

 

That is quite a bit of simplification. And I don't think it makes sense to attempt cover all the details in Wikipedia or forum post. There are books and research papers about SDM stuff, because it is so widely on A/D and D/A converters these days. Lot of companies don't tell much details how their chips work either.

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×