Worlds Greatest DAC and what it does differently

[beerandmusic]

Another thought popped into my head...i wish it would stop...I have sleeping disorders.

 

Anyway...

 

Ok so barrows conceded that if electronics were perfect a 44.1K dac would be sufficient.

I want to take it up a notch to 24bit 96K DAC just to be safe...so moving forward, this i what the worlds greatest dac will be.

 

Now we have to compensate for "imperfect electronics"...

 

but wait...it is already conceded that the dac already recieves the bits perfectly, and the only inputs to a dac are

 

A) perfect bits

B) reference voltage

C) noise

 

hmmmm....

ok since i don't like using DLNA (quirky, ff/rew and a few other idiosyncracies) and will NEVER consider subscription based software), instead of a streamer, couldnt we have a usb->enet->usb interface or some other way to isolate "imperfect electronics" of the pc since spdif supposedly has it's own issues?

 

using a usb->enet->usb, it probably would not be possible to control it then though with existing software? ughghg...

 

i just want the functionality of usb, but with the SQ of streaming...

also, why is it that you don't have quick ff/rew functionality with enet like you do with usb?

 

Just a random thought...back to bed...

 

[beerandmusic]

^^^^i am awake now....boy i think of a lot of stupid stuff when i am half awake...next time i will be smarter to post than when i am half awake (grin)

[Miska]

On 6/10/2020 at 9:31 PM, pkane2001 said:

If you are looking at the differences in the human-audible range, these "VAST" differences would be a VAST exaggeration. A 1kHz sine wave reproduced by most competently designed DACs (possibly excluding some NOS R2R types) will look like a 1kHz analog sine wave. You'll need to zoom in with a magnification of 10,000x times or more to start to see some minor differences, and that would be with some of the poorer performing DACs.

 

Given that the other DAC here is running 16-bit R2R at 192k sample rate, you don't need to zoom much to see stair steps on it. Or in frequency domain to see images at multiples of 192k sampling rate...

 

Vastly different, to a well performing DAC, the difference in image levels is in several tens of dB, even close to 100 dB.

 

[Miska]

On 6/11/2020 at 7:33 AM, beerandmusic said:

Yes, he was...i specifically stated in the thread, "differences within the audible spectrum" and i repeated it many times.

 

I'm pretty sure even in THD frequency distribution figure within audible spectrum differences are well over 10 dB. And then when you take into account things like different digital and analog filter roll-offs and differences in phase responses within audible spectrum.

 

[Miska]

On 6/11/2020 at 7:16 PM, beerandmusic said:

edit to add:: since you believe if everything was perfect that 44.1khz should be sufficient to capture the audible spectrum, I personally think that 96K would likely be more ideal as 44.1K is very close to our boundaries and that 96K "may" be a rudimentary step that would leave no room for argument, and plus it is a multiple of 48k which I understand is more ideal for video, that 96K "may" be a "sweet spot" for both recording and reconstruction.

 

96k is not enough for proper reconstruction with analog filters. Even very early CD players from Philips used 4x upsampling filters to play at 176.4k rate. And these are still far from perfect.

 

96k may be OK'ish for delivery format, but not for running conversion section. These are two different things.

 

[beerandmusic]

11 minutes ago, Miska said:

 

I'm pretty sure even in THD frequency distribution figure within audible spectrum differences are well over 10 dB. And then when you take into account things like different digital and analog filter roll-offs and differences in phase responses within audible spectrum.

 

this is pretty greek to me...

 

question again is, assuming

 

1) original 1khz sine wave recorded at 44.1k

2) all hardware is the same but the dac

3) would there be any measurable differences (within the audible spectrum) between 2 different competent dacs one being pcm 192K and the other upsampled to quad rate dsd at the "analog out"

 

edited I meant to include within the audible spectrum.

 

[beerandmusic]

2 minutes ago, Miska said:

 

96k is not enough for proper reconstruction with analog filters. Even very early CD players from Philips used 4x upsampling filters to play at 176.4k rate. And these are still far from perfect.

 

96k may be OK'ish for delivery format, but not for running conversion section. These are two different things.

 

ok...lets go with 24bit PCM 192K then?  That's really what i am considering anyway.

[Miska]

2 minutes ago, beerandmusic said:

3) would there be any measurable differences between 2 different competent dacs one being pcm 192K and the other upsampled to quad rate dsd at the "analog out"

 

Of course yes. If you look close enough, you can find differences between two DACs of same model, thanks to component tolerances.

 

[beerandmusic]

25 minutes ago, Miska said:

 

Of course yes. If you look close enough, you can find differences between two DACs of same model, thanks to component tolerances.

 

within the audible spectrum that can be heard?

[Miska]

2 minutes ago, beerandmusic said:

ok...lets go with PCM 192K then?

 

As I said earlier, when you get PCM sampling rate at about 1.5 MHz, then R2R ladders with typical analog section begin to look decent. But that is not easy thing to get working properly in first place due to settling time problems at high precision. But luckily there are digital domain tricks that you can do to help the DAC perform better.

 

[Miska]

Just now, beerandmusic said:

within the audible spectrum?

 

Yes

[beerandmusic]

3 minutes ago, Miska said:

 

Yes

pkane seemed to disagree in one of the first posts?  Is he incorrect or misunderstanding what you or I are saying/asking?  If I understood him correctly He suggested you are "vastly exaggerating" ?

[beerandmusic]

It doesn't sound like dacs do their job very well if they cannot reproduce the analog out with consistency and relative accuracy, especially for a simple 1k sine wave?

[beerandmusic]

22 minutes ago, Miska said:

 

As I said earlier, when you get PCM sampling rate at about 1.5 MHz, then R2R ladders with typical analog section begin to look decent. But that is not easy thing to get working properly in first place due to settling time problems at high precision. But luckily there are digital domain tricks that you can do to help the DAC perform better.

 

PCM at 1.5mhz?

when you say digital domain tricks, that sounds like you are referring to within the dac?

I am talking about measurements at the analog output of the DAC, after all digital to analog conversion is done

 

[Miska]

24 minutes ago, beerandmusic said:

when you say digital domain tricks, that sounds like you are referring to within the dac?

I am talking about the analog output of the DAC, after all digital to analog conversion is done

 

It could be inside the DAC, or outside of the DAC. I'm doing it in player software.

 

And yes, I'm talking about analog output of the DAC too. Modern DACs heavily rely on DSP algorithms, to the extent that DSP algorithms largely define base performance of the DAC.

 

Example; here you can see Holo Audio Spring 2 DAC running with 1 kHz -120 dBFS input, TPDF dithered to 24-bit, at 1.4112M sampling rate:

 

And here the same, but data noise-shaped to 20-bit to match linear range of the R2R ladder:

 

You can see that the second one is at least 20 dB (10x) cleaner! In fact it is much more than 10x cleaner, while having actually more dynamic range, but limited by analog noise floor.

 

Another view, here is same DAC running sweep with built-in oversampling (8x) to 352.8k:

 

You can see that the first image around 352.8k is at -60 dB meaning about 10-bit equivalent reconstruction accuracy. And actually four image pair bands visible. At 192k sampling rate it would be much worse.

 

Here's the same, but at 1.4112M sampling rate with oversampling done in player software:

 

You can see there there are no images at least clearly visible at multiples of 1.4112M sampling rate. The difference here is more than 40 dB (100x)!

 

And here's the same again at DSD512:

 

Here you can see that within about 100 dB range, 1.4112M PCM through R2R section and DSD through the DSD section produce similar image levels on this DAC, so we can reach at least decent RedBook reconstruction.

 

In all cases, source file is 44.1k sampling rate. We could also look into narrower spectrum to see differences in there.

 

 

This is just a very brief example what DSP can do to operate the conversion section to perform well.

 

[beerandmusic]

ok thanks for taking the time to share.

 

When i first questioned you, i said for comparative purposes, i wanted to use a schiit for pcm and a rme adi-2 for dsd (because those are 2 dacs that I am considering), and wanted to know if there would be anything that is audible between the 2 assuming most of what i listen to is 44.1k.

 

I used to think that higher resolution would mean "more music", but recently i read that the upsampling is only to push reconstruction noise out of the hearing spectrum.  (maybe i am not phrasing this correctly but that is what i recall). 

And even barrows suggested that a 44.1K dac would be sufficient if not for "imperfect electronics".  I also believed that i read that by upsampling to 192K would be sufficient enough to push this reconstruction noise out of the hearing spectrum (again, i may be using wrong verbiage).  I am sure I will never understand this stuff enough to make a "logical" decision, but i am trying.

 

I keep going back to the purpose of a dac is nothing more than to reconstruct the original analog signal that was converted to digital, and that if a DAC does it's job, they should sound the same....

 

 

 

 

 

[pkane2001]

1 hour ago, Miska said:

 

Given that the other DAC here is running 16-bit R2R at 192k sample rate, you don't need to zoom much to see stair steps on it. Or in frequency domain to see images at multiples of 192k sampling rate...

 

Vastly different, to a well performing DAC, the difference in image levels is in several tens of dB, even close to 100 dB.

 

 

True, and that's why I said 'excluding some NOS R2R types'. I wasn't aware that we were discussing a specific DAC here, but DACs in general. Maybe I missed this part. 

[beerandmusic]

34 minutes ago, pkane2001 said:

 

True, and that's why I said 'excluding some NOS R2R types'. I wasn't aware that we were discussing a specific DAC here, but DACs in general. Maybe I missed this part. 

 

34 minutes ago, pkane2001 said:

 

True, and that's why I said 'excluding some NOS R2R types'. I wasn't aware that we were discussing a specific DAC here, but DACs in general. Maybe I missed this part. 

 

so to clarify pkane, are you saying and confirming with MISKA that schiit bifrost mb DAC does have problems and that there are audible differences at the analog output (even with a 1k sine wave)?

[fas42]

What the world of audio is largely unable to come to terms with, still, is that human hearing is incredibly sensitive to certain anomalies in the sound it hears - this is why nearly all hifi systems always sound like they're faking it; and will never convince one that they're a good replica of the 'real thing'. Worrying about the precision of a DAC, the amount of noise buried deep, deep down, measured in conventional ways, is almost entirely irrelevant - if a brilliantly spec'ed DAC makes good sounds, then it's more by fluke than anything else.

 

If you're worried about what's audible, then the overall integrity of the playback electronics chain is far, far more important - this is why a cheap setup can sound very impressive, because someone has gone to the effort of dotting the i's, and crossing the t's. Impressive looking measurements, as are routinely currently produced, are as close to be being of zero value as one can get, in determining whether, say, the "Wow!" factor will happen.

[pkane2001]

19 minutes ago, beerandmusic said:

so to clarify pkane, are you saying and confirming with MISKA that schiit bifrost mb DAC does have problems and that there are audible differences at the analog output (even with a 1k sine wave)?

 

Audible or not, I'm not going to say since that depends on you, what you listen to and what you can and cannot hear. Suffice it to say that I think it should be audible. To me, a 1kHz that looks like an obvious staircase isn't a proper reproduction of a sinewave. 

[beerandmusic]

2 hours ago, pkane2001 said:

 

To me, a 1kHz that looks like an obvious staircase isn't a proper reproduction of a sinewave. 

I would have to agree with that, and wouldn't want a schiit DAC if it isnt capable of producing even a simple sine wave...i am just surprised that I have never heard this before...even if it does sound better than anything else i have hooked up to my pc...the hunt will continue.

[beerandmusic]

On 6/11/2020 at 7:51 AM, barrows said:

My feeling is that there is some "magic" with DSD 256 (and perhaps above).  But of course this is not really "magic" at all.  High sample rates, including high rates of PCM-like quality allow for relatively simple actual conversion paths.  This is how most Sigma Delta style DACs work.  Tthese high rates also allow for even discrete (non chip based) converters, which give designers additional freedom (if they are clever enough) to develop a unique converter topology which may offer advantages over standard chips.

For chips, when one looks at, say, ESS-it oversamples to a very high rate (similar to DSD rates) and 5, 6, or 7 bits, and then converts to analog from this very high rate.  dCS uses a similar approach, but they do the final conversion into analog using a discrete converter.  Chord, again uses a similar approach, again using a (similar to dCS) discrete final converter stage.

Jussi's (AKA miska) DSC-1 DAC design, now adopted in various different iterations by Holo Audio, Denafrips, T+A, among others, is a DSD based discrete converter stage designed to be fed by a very high rate single bit signal, generally DSD 256 and above.

Mola Mola, in the excellent Tambaqui DAC, uses a variation on the discrete converter theme as well, with the final converter stage being a multi-element switch and resistor set up, similar to DSC-1.  Same with Playback Designs, and I suppose Emm Labs...

I am listening as I type to Bricasti M3 DAC, which uses a different, discrete converter stage design of their own, essentially also based on a high speed switch and filter, for single bit DSD input only.

 

Most of these different DACs sound different, but I have experience now with 4 different single bit based DACs, all of which have used some variation on a discrete converter stage.  All of them have seemed to share, in differing degrees, a quality of conversion which sounds more natural, and easy going to me.  I do not mean that they are rolled off, or "soft" sounding, but that they sound more like music, and less like an electronic representation thereof.

 

There are a lot of really good DACs out there these days, but for me, I do seem to prefer the DAC which use discrete conversion approaches, with high rate DSD input.  This can be done on a chip as well, as with AKM DAC chips' "direct DSD" path option.  But, when a designer goes discrete, they have control of the performance, and they may be able to do better than what is available on a generic DAC chip (or not, as the case may be).  

 

Can you expand more on what "discrete" conversion is, and what the other solution is besides discrete? And how would we know if it uses discrete or "non-discrete"?  Does pro-ject, rme, teac, mojo, or any dac below $1K use discrete? 

[beerandmusic]

On 6/12/2020 at 2:14 PM, Miska said:

 

Of course yes. If you look close enough, you can find differences between two DACs of same model, thanks to component tolerances.

 

Ok, thanks for sharing...i think i understand a "little better" now....is this correct::

 

I guess this is where i was going with this thread, that from a "logical" perspective, 24bit/192k should be MORE than sufficient to fully capture and accurately reproduce all recorded music that we can possibly hear.  Unfortunately, as Barrows points out, that whereas logically that may be true, but because of "imperfect electronics" that it is not true, and that higher sampling rates don't give you more music, but it helps creating the analog output with less noise than would be possible at lower rates.

 

Ok this brings me to another question...can HQP play directly to a DLNA renderer without NAA? (not sure I am using the right terms...i know i can play music from DLNA music server on qnap from jriver to my marantz streamer...can i play from hqplayer to marantz streamer?

 

[Miska]

3 hours ago, beerandmusic said:

Ok this brings me to another question...can HQP play directly to a DLNA renderer without NAA? (not sure I am using the right terms...i know i can play music from DLNA music server on qnap from jriver to my marantz streamer...can i play from hqplayer to marantz streamer?

 

No, but HQPlayer Embedded can operate as UPnP Renderer. (DLNA is sort of obsolete specification for high quality audio, it just specifies bunch of mandatory and optional formats, mandatory ones being such as 128 kbps MP3)

 

[beerandmusic]

2 hours ago, Miska said:

 

(DLNA is sort of obsolete specification for high quality audio, it just specifies bunch of mandatory and optional formats, mandatory ones being such as 128 kbps MP3)

 

MISKA>> mandatory ones being such as 128 kbps MP3

huh?  i dont get this statement?

I can stream DSD256 via dlna..i have been doing so for over 5 years...or are you just saying you can only do somethings with mp3 files?  I have replaced all my mp3's with wav or dsd.