Uniti Atom upscaling

No advantages to software upscaling of the feed to the DAC.  The DAC's own software and processing will have been optimally configures to get the best from Red Book (CD) format that can be achieved using that DAC chip and the associated circuitry.  If you upscale the data the DAC will 'think' the data are native at that format and may optimise playback in a different way that's not optimal for what are still red book data just held in a wider container.

"Upscalling" to DSD isn't actually upscaling as that one is in fact a lossy conversion; so data (and indeed maximum subsequently achievable quality) are actually lost in the conversion process.

Huge 

looking to be educated here please . Are you saying there is simply no benefit to the Roon DSP features and in fact they may actually degrade performance 

Unless you have a DAC that's primarily designed for DSD and which that doesn't process LPCM data streams well...

Then for conversion from LPCM to DSD...

Yes.

My question is about the Atom and which would be better DSD or pcm. Not about external DAC 

  Exactly the same applies to the Atom's internal DAC, there's no difference.

Play it back using the native format in which it was recorded and trust the Naim engineers to do the appropriate optimisation of the DAC playback programming for that data type, rather than second guessing them yourself using ROON (and loosing data in the process).

Of course if you do convert the data it may sound different, and you may prefer that different sound, but it won't actually be any better.  If you prefer the slightly degraded signal fine, the slight loss of quality actually can balance out other issues in the playback system, and hence it really can appear to be better even though there's less information.

Given Roon is now part of the Naim range with the Uniti range ( and you have to assume it will be part of any new streamer range) it would be good to get an official Naim view on the use of Roon DSP with their products . Who do I ping ? 

As I understand it, and it may we’ll be a Noddy upsamples  to Big Ears understanding,  is that most DACs upsample the signal and it requires (for a DAC) a bit of grunt to do particularly the first upsample. 

If this is done before the signal reaches the DAC (in a PC) the DAC  has less work to do, and this easing of the burden can improve the resultant sound. 

I have never come across the idea that the upsampled signal is somehow degraded. There are plenty who upsample to the DAVE DAC.

I think this idea that Naim knows best in all circumstances is a bit short sighted. One may well prefer one or the other but hey isn’t that what makes it all so wonderful. 

.sjb

Terrysmi posted:

Given Roon is now part of the Naim range with the Uniti range ( and you have to assume it will be part of any new streamer range) it would be good to get an official Naim view on the use of Roon DSP with their products . Who do I ping ? 

Naim’s official view!

Why don’t you just listen, it actually will sound the same regardless of any Naim official view. You will either prefer it, notice no difference or prefer no upsampling in Roon. 

It really is quite simple. 

.sjb

Sloop John B posted:

As I understand it, and it may we’ll be a Noddy upsamples  to Big Ears understanding,  is that most DACs upsample the signal and it requires (for a DAC) a bit of grunt to do particularly the first upsample. 

If this is done before the signal reaches the DAC (in a PC) the DAC  has less work to do, and this easing of the burden can improve the resultant sound. 

Surely this this only holds if you can upsample to the rate required by the DAC chip - eg. In case of the DAVE upsample to 768kHz.  If you are only partly upsampling (eg to 192kHz) then the DAC still has to process 192kHz to 768kHz  

Unless you are avoiding ALL upsample within the DAC then it’s better to avoid upsampling prior to the DAC.  And very few DACs can be fed a signal at their “native” rate  

I have never come across the idea that the upsampled signal is somehow degraded. There are plenty who upsample to the DAVE DAC.

This is the upsampling vs over sampling debate - and yes they are essentially the same - and many people felt upsampling DACs (where the upsampling was done with DSP prior to the DACs oversampling are inferior.  

As someone said above; the algorithms for oversampling (upsampling) within a DAC may well act differently on a 192kHz signal than on a 44.1kHz and may result in an inferior sound  

Sloop John B posted:

As I understand it, and it may we’ll be a Noddy upsamples  to Big Ears understanding,  is that most DACs upsample the signal and it requires (for a DAC) a bit of grunt to do particularly the first upsample. 

If this is done before the signal reaches the DAC (in a PC) the DAC  has less work to do, and this easing of the burden can improve the resultant sound.

Tat doesn't take into account that the programming in the digital filters in the DSp and/or DAC are optimised for a given sample rate in knowlege of all the surrounding electronics.  If you present the same data at a different sample rate (which is what up-sampling does) then you don't get the benefit of this adaptive optimisation of the processing.

Sloop John B posted:

I have never come across the idea that the upsampled signal is somehow degraded. There are plenty who upsample to the DAVE DAC.

The original question is not strictly about up-sampling but about LPCM to DSD data conversion.
Unlike simple up-sampling, LPCM to DSD conversion is a lossy process and hence the signal is degraded.

The upsampling to the DAVE DAC is done by a dedicated up-sampler that is specifically designed to precede the DAVE DAC.  This up-sampler is itself specifically optimised to take account of the subsequent processing done in the DAVE DAC and it's analogue electronics.   - Different situation entirely.

I don't understand your contention that LPCM conversion to DSD is lossy. Surely transcoding from one lossless format to another is not inherently lossy. What information is lost in the process?

The problem is the way in which data are contained by DSD and LPCM.  The differences are in the way that information is mathematically distributed between the amplitude domain and the time domain.  The effect is that there is no direct correspondence of one information pattern and the other.  Whenever analogue data are subjected to the entropic process of digitising the data some data are inherently lost as a function of the entropy (e.g. the data in the 'gaps' between samples are not encoded in the digital signal for LPCM).  This digitisation loss is different from the lossless storage of the data: As both formats are lossless, there's no subsequent mathematical loss of data by compression (or other processing) of the data.  However the data that are lost by the entropic process of digitising the data are different for LPCM and DSD.  Since the lost data are different, then when converting from one to the other the information lost in one format cannot be recreated in the new format, but the data that cannot be stored in the new format are also lost - hence the final result is less than the original before the conversion.

Each may be lossless in their own right, but as they can hold slightly different interpretations of the analogue data, the conversion can still be lossy.

Huge posted.

Sloop John B posted:

I have never come across the idea that the upsampled signal is somehow degraded. There are plenty who upsample to the DAVE DAC.

The original question is not strictly about up-sampling but about LPCM to DSD data conversion.
Unlike simple up-sampling, LPCM to DSD conversion is a lossy process and hence the signal is degraded.

The upsampling to the DAVE DAC is done by a dedicated up-sampler that is specifically designed to precede the DAVE DAC.  This up-sampler is itself specifically optimised to take account of the subsequent processing done in the DAVE DAC and it's analogue electronics.   - Different situation entirely.

My point was that many use Roon (mostly with HQP) to upsample data to DAVE. 

Now just because people do it doesn't mean it is correct but I'm presuming all of them don't have cloth ears or are "balancing other issues in the playback system". 

I'm presuming it sounds better that way which is ultimately the goal. 

.sjb

Sloop John B posted:

Huge posted.

Sloop John B posted:

I have never come across the idea that the upsampled signal is somehow degraded. There are plenty who upsample to the DAVE DAC.

The original question is not strictly about up-sampling but about LPCM to DSD data conversion.
Unlike simple up-sampling, LPCM to DSD conversion is a lossy process and hence the signal is degraded.

The upsampling to the DAVE DAC is done by a dedicated up-sampler that is specifically designed to precede the DAVE DAC.  This up-sampler is itself specifically optimised to take account of the subsequent processing done in the DAVE DAC and it's analogue electronics.   - Different situation entirely.

My point was that many use Roon (mostly with HQP) to upsample data to DAVE. 

Now just because people do it doesn't mean it is correct but I'm presuming all of them don't have cloth ears or are "balancing other issues in the playback system". 

I'm presuming it sounds better that way which is ultimately the goal. 

.sjb

Do you accept that

1   Most quality DAC systems use oversampling filters and hardware

2   That the details of the DAC system hardware (DAC chip & analogue electronics etc.) can be taken into account when writing and optimising the internal filter algorithms

3   That the data word size, data rate can be used to control how the internal filter optimisations are applied by the DAC system

4   That up-sampling an LPCM data stream to higher rate and/or larger word size LPCM data stream adds more data, but no more information, to the data stream

Whatever I accept or not has little  impact on what I'm saying, which is,  that quite a few people think the sound they get from their system using upsampling is better than without. You seem to be using theory to discount practice.

I presume the resampling and dither filters are also having an impact as powerful PCs can simply do more heavy lifting here.

.sjb

Sloop John B posted:

<snip> quite a few people think the sound they get from their system using upsampling is better than without.

<snip>

OK, I can agree with that - no problem.

Sloop John B posted:

<snip>

You seem to be using theory to discount practice.

<snip>

No, I'm distinguishing between practice and the perception of practice.

Sloop John B posted:

<snip>

I presume the resampling and dither filters are also having an impact as powerful PCs can simply do more heavy lifting here.

.sjb

Even if the data are up-sampled before being submitted to a DAC system, the DAC system will still have to apply its digital filters, so in practice, the difference is academic as the load on the DAC pre-processor isn't significantly reduced!

Think, perceive - you use the words pejoratively - what other way should one judge sound?

.sjb

Well now we're talking about sound let's look at the wider situation:-

A digital signal is filtered and reconstructed by a DAC to generate an analogue signal (no sound here).

The analogue signal is amplified and modified by an amplifier (still no sound).

The amplified signal is heavily modified by the crossovers, speaker drive units, speaker cabinets and the room in which they are placed including being split into bands, incurring many dynamic changes and phase changes and finally converted into sound.

My suggestion is that a slightly less optimal reconstruction of the analogue signal in a particular way, may partially offset a particular piece of suboptimal processing downstream in the amp or speakers.  In this way the final sound perceived by the listener can seem better, even though from the perspective of the DAC alone, the processing is suboptimal, and a different downstream system would highlight the suboptimal processing in the DAC subsystem.

So...

I stand by my position...

The processing in the DAC subsystem can be suboptimal and, due to subsequent modification by other components in the system, the resulting sound can be perceived as better leading to a user thinking that the sound is better in absolute terms.  The problem here is one of the lack of a true reference (we can't hear the unmodified signal from the DAC) and the limitations of human perception and psychology.

At the end of the day, that the sound is perceived as better by that one person using that specific processing and that specific set of replay equipment in that specific room means that:-
          For that one person, the sound is better when (and just possibly only when) using that specific processing and that specific set of replay equipment in that specific room.

It means nothing more than that.  It doesn't mean that the preprocessing improved the optimisation of the DAC or that the particular DAC with the up-sampling is performing better with it than than without it.

Must be a awful lor of sub-optimal systems out there!

If I have a bag  of chips and remove one tiny crispy bit-  Cover them in salt and vinegar, eat and enjoy - I've not eaten what the chipper had originally given but do enjoy it all the more. 

You're presuming the bit that gets lost has a bigger effect - on the sound - than the addition of  filter and dither. I'm simply suggesting that real world consumption suggests you are wrong about the effect on the sound. 

.sjb

You need the qualification... For that person for that particular processing, for that particular system, for that particular room with all the deficiencies entailed therein.

The chips analogy is factious and in this context, is totally meaningless.

Furthermore, if you read what I wrote you'll see that I'm assuming that the biggest deficiency is the speakers and the room.  In the context of that, the effects of a suboptimal filtration (and as you pointed out the degradation incurred by a second application of dither) may partially offset other deficiencies in another part of the system (as I pointed out previously).

Lastly, please don't repeat trying to reinterpret my points by changing them to a meaning you can then subsequently demolish.

Huge posted:

 

Lastly, please don't repeat trying to reinterpret my points by changing them to a meaning you can then subsequently demolish.

Sorry, I thought we were having a quite civil discussion, apologies if I somehow offended you, not my intention at all. 

.sjb

Ah, sorry I seem to have misinterpreted your intention, your previous post contained an unfortunate form of words and small adjustment to the meaning of one of my points.  On the surface, it appeared that you were intending to use a common debating technique that's intended to lure the other party into a logical trap.

It's obvious form the post above that it's wasn't your intention to prepare the ground for that type of attack.  just a coincidence that you expressed yourself precisely that way.  Sorry I misinterpreted your intent.

The previous night I was playing verbal games with someone who's a barrister I think some of the verbal sparring is still stuck in my head! 

 The irony here is that he's an expert in language and linguistic logic, and I have problems with language but I make up for it by combining geometry and symbolic logic.  So sometimes I do misinterpret language particularly when the conversation isn't face-to-face.  On the other hand exploring scenarios with him is interesting as we use logic in such different ways that we can't predict each other's next move (and that's very unusual for him given his job).