Denafrips DACs might not actually be NOS?

[numlog]

 

29 minutes ago, The Computer Audiophile said:

Suggesting that current audio hardware is fully capable of all that's needed is a bit strange to me

Could you explain more detail what you think is needed and why current hardware isn't capable? 

[idiot_savant]

@The Computer Audiophile I don't really know what I've done to upset you. When I say I'm not really interested in implementations, I mean if the concepts aren't defined properly then implementations are irrelevant? I'm talking about thought experiments. If you posit that by using more horsepower for a task in a PC you can get a measurable parameter that is better than doing it internally, that must be quantifiable? My point is that saying that a denafrips DAC running NOS with HQPlayer is better than something else makes it hard to pin down what is causing that effect - it is obvious, for example that *this* particular DAC *needs* to be fed high sample rates in NOS mode, as the measurements show that even at 96kHz it is droopy in the audio band. Another thing to factor in if you look at the OS performance, is that even the "sharp" filter is not even anywhere near as performant as other products ( so 70dB suppression of 19.1kHz tone, vs most other DACs filters acheiving > 100dB ) - so saying it sounds better in NOS mode with HQPlayer vs OS native, you're comparing what is probably a very nice filter in HQPlayer against a not very good one inside the unit in OS mode...

 

@PeterSt - It doesn't really matter what the DAC chip is - so you've got a 1k tone @ 44.1kHz, you present it to the DAC at 705.6kHz -so does the DAC input see sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample1,sample1,sample1,sample1,sample1,sample1,sample1 etc. 

And you're *sure* that the 1kHz tone is -3dBFS going *in* to the DAC?

The reason I ask is that NOS will add a bit of gain ( because the original signal is still at full scale, and you're adding images via NOS )

 

your friendly neighbourhood idiot

[PeterSt]

5 minutes ago, idiot_savant said:

And you're *sure* that the 1kHz tone is -3dBFS going *in* to the DAC?

 

Yes, I am sure. I could show you clipping from a file not being -3dBFS. And do notice that my filtering is interpolating which does not allow for a higher output signal than its input signal (not for average and also not for "tops" (or valleys - haha)).

 

Btw, I could drop the signal another 3dBFS if you want, but currently someone is working on that DAC so I can't show you now.

 

Why would this matter with filtering improving ? (signal gets lower ? :-)

Anyway, we also test with lower output and this really does not matter (except for the S/N doing things, which makes THD+N also worse.

 

The 0.04% is a dead-normal figure as all NOS DACs show that.

On-topic and repeat: for the Denafrips the 0.004% looks strange to me. It should either be better (with filtering) or worse Genuine NOS).

[PeterSt]

17 minutes ago, idiot_savant said:

the DAC at 705.6kHz -so does the DAC input see sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample0,sample1,sample1,sample1,sample1,sample1,sample1,sample1 etc.

 

I suppose this was a question, right ?

Earlier on I wanted to say "I myself determine the sample and hold" but I was not sure about the decentness of the answer. Anyway, Yes. Each sample has an explicit value, determined by the in-PC filter.

[davide256]

What is the expected bad behavior of linear interpolation at the limits/singularity's and do we see that here with Denafrips?

Or does it diverge at these points implying some kind of modified algorithm for interpolation?

 

Does sound like Denafrips NOS mode would yield unpredictable results with oversampling programs built on true NOS mode behavior.

Any HQPlayer users experiencing an issue?

 

[PeterSt]

22 minutes ago, idiot_savant said:

as the measurements show that even at 96kHz it is droopy in the audio band.

 

Thinking about this twice, I would say that this can only because by some error (bug).

OR

some erroneous analogue filter. This may not necessarily be a bug but it may mask something else purposely (take out some (whining) peak)

[semente]

23 minutes ago, idiot_savant said:

I mean if the concepts aren't defined properly then implementations are irrelevant? I'm talking about thought experiments. If you posit that by using more horsepower for a task in a PC you can get a measurable parameter that is better than doing it internally, that must be quantifiable?

 

This post could help (compares NOS, internal SRC and filtering, external SRC and filtering) but the formating has gone bad (maybe @The Computer Audiophile can sort it?):

 

Also this topic: https://tinyurl.com/n8epw24r

[PeterSt]

40 minutes ago, ecwl said:

But I see lots of people getting upset over NOS R2R not being truly R2R.

 

OK, part of the understanding could be about what's not truly which. 😏

 

An R2R DAC should be truly that, because it is built around R2R ladders (if the "division" - as in R/2R is different than I wouldn't care about that). I'd say that there should be no doubt, already because the ladders can be seen with discrete ladder DAC's (as with the Denafrips) or else the chips could be observed. And easy for 24 bits:

This can only be the PCM1704.

 

So I'd say your "statement" should be different:

"But I see lots of people getting upset over NOS R2R not being truly NOS."

 

Agreed ?

So if I Upsample in-PC (this is not Oversampling, BTW) is my DAC than NOS ? It definitely is. But if I "demand" people to use upsampling/filtering because that is the whole idea about it ? then the chain will net not be NOS at all. It still would be filterless as in "no analog filter". So mind you, this is quite crucial for NOS die-hards who now suddenly get some best of both worlds thing. You saw my THD+N figures and you can take it from me that genuine NOS is THD+N 0.04%. This is super bad. Add an analogue filter behind it, and I doubt whether THD+N (which is in-(audio-)band) will improve. However, it will prevent aliasing to some degree and that in itself would imply distortion (THD). Same with a decent (sufficiently steep) digital filter.

The difference with the analogue filter alone, however, would be the staircasing being way higher.

 

@idiot_savant, Please consider that as the reason of digital filtering really helping vs upsampling only not helping much. This should be in the aliasing department and not the staircasing thing (OK, 20KHz is a huge staircase, but ...).

 

@ecwl, I am afraid I drifted off. It is not all that easy. Maybe you should change some of your "NOS" or "R2R" parts into "PCM" parts. That compares better with (versus !) DSD.

[The Computer Audiophile]

1 hour ago, ecwl said:

I have to admit I’m very confused by this discussion.

Granted, we have no idea what Denafrips Ares is doing in it’s implementation of NOS R2R playback.

But I see lots of people getting upset over NOS R2R not being truly R2R. But I’ve mentioned in other posts before that many DSD playback is not truly DSD either. And it seems that nobody gets very upset about that and vigorously defend it as “normal”.

To clarify, almost all “true” DSD playback is actually DSD with shift register with multiple elements. So technically, you’re not hearing “the original DSD” signal because of the multiple elements with shift register. And people tell me that’s normal and that’s still true DSD.

Let’s imagine Denafrips NOS also uses a shift register system for playback with say 16 R2R DACs all shifting at 16fs for 44.1kHz so you’re getting 16 R2R DACs all playing NOS except they’re all shifted by 705.6kHz = 1.4ms. To me, that’s still NOS (albeit with a type of filtering of some sort, which you’ll always need with NOS DACs, usually with an analog filter)

So how exactly is that different than a 2.822MHz DSD with 32-element shift register playback? Are we going to have people start demanding that their DACs be 1-element DSD DACs or else, their DSD DACs aren’t pure?

 

That said, maybe my understanding of NOS R2R DACs and DSD DACS are too elementary so perhaps somebody with more insights can explain to me the difference?

 

Agree, this is similar to the point I'm trying to make. The world isn't black and white and a company isn't misleading people or wrong because it's doing something different than what a "purist" may believe should happen. 

 

More information would be great, just so people can understand what's going on (for those that are interested), but it seems that many people are only interested in something else. 

[The Computer Audiophile]

1 hour ago, idiot_savant said:

If you posit that by using more horsepower for a task in a PC you can get a measurable parameter that is better than doing it internally, that must be quantifiable?

It's all measurable. You just seem to be writing it off without knowing much about it. Take a look at the filters and modulators in HQP. They are really powerful and can be resource intensive. The FPGA hardware to run them is about $2,000 (if I remember correctly) without any markup. Nobody has put this into a DAC yet. 

[idiot_savant]

@PeterSt - the increase in THD you are showing is a a slight rise in 3rd Harmonics, which is exactly what you get if you overload slightly... ( by having all the ultrasonic stuff present ). Oh, and no analogue filter? So you have large images above 768k? And the 96kHz frequency response has already been explained by it being a linear interpolate rather than NOS ( so if you imagine scaling the graph I posted yesterday, you'll see it's -1.29dB @ 20kHz for linear interpolate vs -0.64 for NOS

 

 @The Computer Audiophile - Who ever said I'm writing it off? All I'm doing is questioning the black and white view that throwing more horsepower at a problem is always the solution, and just telling me it's really resource intensive isn't really that instructive. All I'm doing is trying to point out some of the trade-offs, and the difficulty in making comparisons between oranges and apples. You're the one stating that there is no current hardware currently capable, without stating capable of what?

 

your friendly neighbourhood idiot

[The Computer Audiophile]

1 minute ago, idiot_savant said:

All I'm doing is questioning the black and white view that throwing more horsepower at a problem is always the solution

Nobody here has said that. 

 

1 minute ago, idiot_savant said:

You're the one stating that there is no current hardware currently capable, without stating capable of what?

Here's a link to the software that many people use - https://www.signalyst.com/consumer.html

 

 

[idiot_savant]

2 minutes ago, The Computer Audiophile said:

Nobody here has said that. 

 

Here's a link to the software that many people use - https://www.signalyst.com/consumer.html

 

 

 

But using HQP you can take this DAC way farther than any internal filtering and over sampling could do. The horsepower in any DAC is just too weak to do what HQP does. That’s why people like NOS type DACs. 

[semente]

Just now, idiot_savant said:

 

But using HQP you can take this DAC way farther than any internal filtering and over sampling could do. The horsepower in any DAC is just too weak to do what HQP does. That’s why people like NOS type DACs. 

 

Yes, some people like NOS DACs (a list here) so that they can feed them previously upsampled and filtered and noise-shaped Redbook.

 

But other people like NOS DACs with Redbook. People using Audio Note, Lampizator, Border Patrol, AMR, 47Labs, Zanden, etc. DACs.

[idiot_savant]

@The Computer Audiophile - look, I keep saying, I don't know why you think I'm some clueless buffoon. I've been to that page and it tells me there are a load of filters, but that's about it?

 

I'm sure it's wonderful, and well designed, and I've not said a single word disparaging it?

 

your friendly neighbourhood idiot

[The Computer Audiophile]

16 minutes ago, idiot_savant said:

I don't know why you think I'm some clueless buffoon

I haven't said anything of the sort. 

 

The impression I get is that you now quite a bit, but may be unwilling to exit a comfort zone or are quite skeptical of external oversampling and noise shaping etc... Thus, you haven't really looked at it much. 

 

 

[PeterSt]

19 minutes ago, idiot_savant said:

and the difficulty in making comparisons between oranges and apples. You're the one stating that there is no current hardware currently capable, without stating capable of what?

 

I hope you guys don't end up in a fight and that we must miss your insights for 10 years again. But ... maybe it is good to know that the world really has changed:

 

I would say that there's not a single soul any more who uses a DAC without the filtering in advance of it. Thus, everybody uses some kind of in-PC filtering. That by far most use HQP is something I can't help (they should be using XXHighEnd obviously :-) but hey, this is a fact. 

Fact is also that Miska from HQPlayer will tell you that no hardware can do the job he is capable of in-PC. This, of course, is BS. But in the end not so much BS at all, because it is about the WHAT is done, and like me in XXHighEnd, I can change it on a daily basis for you the customer, and it WILL determine most of the sound as such (I am not talking SQ per se, but just the nature of the sound). To each their own, but as long as we can set in-layer how the sound is to be, just by means of selecting a filter(type) which overrules what happens in-DAC and which almost per definition is worse-sounding (oops) ...

 

... then you should give in somewhat ?

I know of no-one who uses XXHighEnd and who finds HQP to be sounding better. The importance of this is ... it is the filter which determines the sound. That people (me included) coincidentally find the one player sounding better than the other, alas.

So let's turn this story upside down a little:

 

30 minutes ago, idiot_savant said:

Oh, and no analogue filter? So you have large images above 768k?

 

Yeah, isn't that great. Well, what if HQP could undo that by means of a lot of horse power.

I am not saying it can, but similar things it surely can do.

 

Or another twist: my filter virtually does not use any CPU at all (you will see 0% during playback only). And now I claim that sounds way better (hey, it does). It is still filter related because it is power consumption related.

Now who is right about what ?

And how to do something about that when all happens in-DAC ? ... oh wait, this thread is about that, right ?

 

haha

[etane]

Personally, I believe whether whatever iteration of "NOS DAC" is compatible with whatever post process software such as HQPlayer is a red herring.  The question should be IS THE NOS DAC AUTHENTICALLY A NOS DAC? 

 

NOS DAC is well defined by enthusiasts by products that use NOS DACs such as the list provided by @semente:

But other people like NOS DACs with Redbook. People using Audio Note, Lampizator, Border Patrol, AMR, 47Labs, Zanden, etc. DACs.

 

And, if it differs in design, implementation, technology and, most importantly, in SOUND, then it's not classically, technically or authentic(ally) NOS.   Of course, R2R removes the possibility of using traditionally used NOS chips from TDA or AD.  So, maybe by definition NOS R2R is NOT NOS and consumer should not expect NOS R2R to sound authentically NOS.

[semente]

35 minutes ago, PeterSt said:

I would say that there's not a single soul any more who uses a DAC without the filtering in advance of it. Thus, everybody uses some kind of in-PC filtering.

 

Peter, how long have you been in self isolation for? I am a member of other forums and most people there do not use a computer, nor a streamer.

[The Computer Audiophile]

4 minutes ago, etane said:

Personally, I believe whether whatever iteration of "NOS DAC" is compatible with whatever post process software such as HQPlayer is a red herring.  The question should be IS THE NOS DAC AUTHENTICALLY A NOS DAC? 

 

NOS DAC is well defined by enthusiasts by products that use NOS DACs such as the list provided by @semente:

But other people like NOS DACs with Redbook. People using Audio Note, Lampizator, Border Patrol, AMR, 47Labs, Zanden, etc. DACs.

 

And, if it differs in design, implementation, technology and, most importantly, in SOUND, then it's not classically, technically or authentic(ally) NOS.   Of course, R2R removes the possibility of using traditionally used NOS chips from TDA or AD.  So, maybe by definition NOS R2R is NOT NOS and consumer should not expect NOS R2R to sound authentically NOS.

Perhaps we need more or better terminology due to different topologies and DACs on the market. 

[idiot_savant]

@etane - so do *you* think a NOS DAC should be filterless with redbook ( 44.1/16 ) material? No PC, no external OS box? And if so, why? And does this necessarily match with a DAC type ( e.g. must be R2R, sign-magnitude, a particular chip )?

 

 

 

your friendly neighbourhood idiot

[semente]

I wonder if this can shed some light:

 

PHILIPS OVERSAMPLING SYSTEM FOR COMPACT DISC DECODING

April 1984 
The sampling process which converts a digital audio signal from binary numbers back to its original analog form generates spurious frequencies, which must be filtered out of the final wave form. Most brands of Compact Disc players use analog filters for this, usually in a system consisting of a 16 -bit D/A converter, a sample -and -hold circuit, and an analog low-pass filter (Fig. 1).

 

 

This, however, can be difficult to do accurately. First, the D/A converter must be linear to within one-half the value of the least significant bit (LSB). However, '/2-LSB accuracy of the dividing steps becomes more and more difficult to achieve as the number of such steps, or bits, increases. For 16 -bit D/A converters, low yield and high cost can easily be obstacles to practical manufacture.

 

"By oversampling at fourtimes the original sampling frequency, the original noise energy is now spread over a band four times as wide."

 

A second problem is caused by analog filtering. A filter steep enough to adequately remove residual components above the audio band must inevitably be a complex one, degrading the signal accuracy and introducing phase distortion. Even an active lowpass filter has a large amount of phases shift near its cut off frequency. Such a filter also generates noise and requires high-speed operational amplifiers, which have high power dissipation and require tight component tolerances to maintain low ripple in their pass -band. Temperature changes and component aging of such filters also affect performance adversely.

 

Philips engineers have found a way to carry out most of the essential filtering process digitally. This approach is used in the players sold by Philips under its own name and under its U.S. brand names of Magnavox and Sylvania. It has also been adopted, in whole or in part, by some other manufacturers.

 

continues here -> https://www.dutchaudioclassics.nl/Philips-oversampling-system-for-compact-disc-decoding/

[etane]

26 minutes ago, idiot_savant said:

@etane - so do *you* think a NOS DAC should be filterless with redbook ( 44.1/16 ) material? No PC, no external OS box? And if so, why? And does this necessarily match with a DAC type ( e.g. must be R2R, sign-magnitude, a particular chip )?

your friendly neighbourhood idiot

I can't directly answer your question as I am not technically inclined.  I drank 47lab's koolaid and understood the reason why NOS dacs are the only digital source I could effortless listen to is because it lacks brick filter, O/S, PLL and such.  Whether the source hardware is PC or software is not redbook, I don't think it matters.  I think it does matter that additional processing is added to the DAC chip.  To some, it's like adding ketchup to sushi.

 

Just want to add, I've moved away from NOS DACs as Topping D90 offers me a sound that is very close to what I am familiar with NOS DACs, inky blacks and lack of glare.  I've put an order in on Singxer SDA6 and expect it to offer the same menu but with better results plus it has a "NOS" mode haha.

 

[manueljenkin]

3 hours ago, The Computer Audiophile said:

That's understood. 

 

You listed tons of stuff that really shows you haven't looked much into the world of over sampling outside of DACs and I attempted to get someone involved to drop more information into this thread. Suggesting that current audio hardware is fully capable of all that's needed is a bit strange to me, but alas, if you aren't interested that's OK to.

I have explored a fair bit on this, and I haven't been impressed with any Hqplayer interpolator, technically or sonically (a smooth fft chart is no guarantee of optimal random signal performance which is more critical for audio). Also sinc + 44.1k doesn't sound anywhere close to as good as high res PCM or arc predict + 44.1khz (which sounds quite great as well). Now I don't want to hold this universal either. Of course there may be other systems and preferences that might make HQP work fine in other systems. But it's a vague thing to assume someone's knowledge or experience is limited just because they are not impressed by something you are impressed on.

 

Point is, it would be a short sighted view to think a LTI interpolator is end all fix for a real world signal interpolation scheme, one that also involves deviations on the analog side, and also the thought that everything needs massive computation to be accomplished. Wadia and luxman have had products with spline based interpolators. There are many dacs that use custom no pre ring apodizing filters matched to their dac analog profile. There's a few where analog and digital part play together (almost all ess dacs, and more). A gazillion tap filter is useless if the actual interpolation algorithm is not the optimal choice, it is useless if all the claimed benefits gets buried in randomness of intrinsic electrical and magnetic interactions in the analog stage.

 

I have respect for everyone trying every approach, but unfortunately, people tend to think they've got the grasp hold of absolutes just by looking at synthetic charts. Real world systems and signals are too profound and complex. I have seen what's possible with efficient customized and optimal interpolation filter design and wouldn't ever think about a sinc filter for high fidelity audio again.

[semente]

4 minutes ago, etane said:

I can't directly answer your question as I am not technically inclined.  I drank 47lab's koolaid and understood the reason why NOS dacs are the only digital source I could effortless listen to is because it lacks brick filter, O/S, PLL and such.  Whether the source hardware is PC or software is not redbook, I don't think it matters.  I think it does matter that additional processing is added to the DAC chip.  To some, it's like adding ketchup to sushi.

 

 

 

You need to cut down on the koolaid, the additional processing results in a more accurate reproduction of the signal.