Denafrips DACs might not actually be NOS?

[The Computer Audiophile]

I think the issue is that we are missing a bunch of information and people are just speculating. That’s only slightly interesting to most people. 

[semente]

15 minutes ago, davide256 said:

The OP is a Youtube audio reviewer with 12K subscribers... they have a venue thats more suited to attract a manufacturers attention. There is also a review of the Pontus on this site... comments there are more likely to get a response as prospective purchasers will be affected. A random forum discussion... not  likely to get a response

 

The post that you quoted does not appear to be engaging Denafrips in the discussion.

[semente]

16 minutes ago, The Computer Audiophile said:

I think the issue is that we are missing a bunch of information and people are just speculating. That’s only slightly interesting to most people. 

 

And it upsets fanboys...

[The Computer Audiophile]

3 minutes ago, semente said:

 

And it upsets fanboys...

It certainly could. But on the other hand, if we had more information, it may make them happy because there may be something going on that's contributing to the positive results everyone is hearing. This is why I asked about pros and cons of what people believe is going on.

 

Some people always assume nefarious intentions and like to take down companies while reveling in schadenfreude. Not me. 

[GoldenOne]

I just want to make clear, that I made the original post because I thought it was interesting, and in the hopes that either denafrips or someone else would be able to provide further information or suggestions for testing. Which is what @idiot_savantdid (thank you for that).

This is not and was not intended to be a "Denafrips bad" post. If they are lying about the DAC being NOS that is indeed concerning. But given as the DAC sounds fantastic in OS mode and most people seem to prefer it in that mode anyway, the content of the OP is entirely separate from whether or not this is a good dac. (Which it is)

You can have a constructive discussion or criticism of a product which you like. There are plenty of products I love which I have issues with either in terms of design or business practices, and plenty of products I dislike which also have attributes I am fond of or appreciate.

There is no need to lump things into a "100% good" or "100% terrible" box

[numlog]

1 hour ago, The Computer Audiophile said:

I think the issue is that we are missing a bunch of information and people are just speculating. That’s only slightly interesting to most people. 

 they call it NOS, it isnt NOS, no speculation involved here. The hows and whys are nice to know, but doesnt change the fact

[The Computer Audiophile]

6 minutes ago, numlog said:

 they call it NOS, it isnt NOS, no speculation involved here. The hows and whys are nice to know, but doesnt change the fact

But the big part that's missing, is what's actually going on and why. It's clearly doing something other than OS and straight NOS and I'd love to know the details. Perhaps this gives them better performance and there really isn't a term for the approach, with NOS being closest. I have no idea.

 

The comments are from some are typical accusatory, the world is black & white style that really don't help anyone. 

[numlog]

To me it looks like linear interpolation aswell, a very primitive form of OS but OS nonetheless. It would help to reduce the amount of ultrasonic content on the output compared to NOS but comes at the cost of high-end roll off. A frequency response graph could confirm that. Probably done to improve measurements.

 

 

 

[GoldenOne]

21 minutes ago, numlog said:

To me it looks like linear interpolation aswell, a very primitive form of OS but OS nonetheless. It would help to reduce the amount of ultrasonic content on the output compared to NOS but comes at the cost of high-end roll off. A frequency response graph could confirm that. Probably done to improve measurements.

 

 

 

Post on that is here:

 

[idiot_savant]

My take on this isn’t actually about a “gotcha”, denafrips are evil or rubbish - it’s just that there is so much speculation about how something may be better even though you can’t measure it, that I’d hope people would pick up on something that is clearly being measured. 

Here you have something that is measured, looks like linear interpolation in the time domain, looks like linear interpolation in the frequency domain on  two units measured with two sets of test equipment. And to be clear something that is even droopier than NOS is not a minor thing - so it’s a deliberate design decision that deserves talking about. 

 

As for the gain ranging, this is speculation on my part but it would be really good to hear an explanation from the manufacturer?

 

the point is that measurements may not be the final determiner of saying how something *sounds*, but they can tell you a lot about what something *does*
 

 

your friendly neighbourhood idiot

[numlog]

Your suggestion that it is related some fixed rate for DSP or compensation is most plausible, I dont think Denafrips will ever share the exact reason.

 

Considering the DAC already has an OS mode it wouldn't really make sense to add interpolation to the NOS mode for reasons related to measurements and risk this exact sort of discovery happening (frankly Im surprised it wasn't discovered sooner), from a frequency response perspective it already measures worse than NOS.

If the DAC couldn't operate at low sample rates they could still get away zero order hold operation (repeating samples) which would look and behave effectively like NOS. This suggests some other sort of limitation.

 

[etane]

Would be good to know whether there are different classifications of NOS especially if it differs from the original definition:

 

https://www.sakurasystems.com/articles/Non-oversampling-DAC.html

[taipan254]

I've been very wary over the years of purchasing audio products from China versus supporting companies based in the U.S. and allied countries (what can I say - I like to buy either local or from friends when I can! Of course, this doesn't always happen given complex global supply chains dependent on Chinese manufacturing... and there are plenty of U.S. and allied companies that I do not want to support as well... AHEM MQA / MERIDIAN!).

 

BUT Denafrips has been getting so much positive attention that I jumped in last month and purchased an Iris DDC (for a variety of reasons... one being that I cannot afford to make a custom server right now). While I've only had it for a short period of time, I think it is an EXCELLENT product and has certainly improved my listening experience. 

 

However, I'm saddened to see WHAT APPEARS TO BE deceptive advertising here. I also wonder why the Chinese founder / engineering team are silent, despite Alvin being a very effective Singaporean salesman / front man / advocate for them? Further, there was a Denafrips "knock-off" that circulated under a different brand name as well (Musician Pegasus I think? I feel like @The Computer Audiophile was gonna review it but didn't?) which didn't make me comfortable when I was considering purchasing an Ares II. 

 

All told these aren't great data points if you're Denafrips or Vinshine and you're trying to build a reputable brand. Oh well. This will be interesting to follow. 

[The Computer Audiophile]

I wouldn't jump to any conclusions without more information. 

[idiot_savant]

@etane- wow, is that like the NOS bible?

 

Chris, trying not to jump to conclusions, but the denafrips is unquestionably doing a linear interpolate rather than NOS - if you overlay the Stereophile filter response graph with the one I provided, then compare at 96k… or look at Goldensounds scope shots-

It may be an honest design error, or desired, so some comment would be helpful?

 

Is the linearity graph a measurement error?

I’ll lay my cards on the table and say that NOS is IMHO a flawed approach anyway… but I am an idiot

 

your friendly neighbourhood idiot 

[etane]

16 minutes ago, idiot_savant said:

@etane- wow, is that like the NOS bible?

 

I think it is, isn't it? 

[The Computer Audiophile]

28 minutes ago, idiot_savant said:

may be an honest design error, or desired, so some comment would be helpful?

 

Completely. A comment or more info would be great. It’s clearly not OS and not a traditional by the book NOS as defined. 
 

 

29 minutes ago, idiot_savant said:

lay my cards on the table and say that NOS is IMHO a flawed approach anyway

Even when using far better over sampling prior to the DAC in something like HQPlayer?

[idiot_savant]

Well, it’s getting late here, but I’m afraid on first look the sums in that are frankly implausible…

 

 

your friendly neighbourhood idiot 

[idiot_savant]

@The Computer Audiophile good point - maybe I should have said “a NOS playback *system* is IMHO a flawed approach, and offering a NOS filter at 44.1kHz is a bad idea under most circumstances*”

* maybe you hate your tweeters, or your dog

 

*if* this unit is using a linear interpolate to generate ( say ) 768k internally, and you feed it 768k via eg HQplayer it probably is irrelevant. 

 

playing back  44.1kHz audio unfiltered is IMHO a bad idea, and I’m genuinely interested as to why people disagree. 

 

your friendly neighbourhood idiot 

[The Computer Audiophile]

3 minutes ago, idiot_savant said:

@The Computer Audiophile good point - maybe I should have said “a NOS playback *system* is IMHO a flawed approach, and offering a NOS filter at 44.1kHz is a bad idea under most circumstances*”

* maybe you hate your tweeters, or your dog

 

*if* this unit is using a linear interpolate to generate ( say ) 768k internally, and you feed it 768k via eg HQplayer it probably is irrelevant. 

 

playing back  44.1kHz audio unfiltered is IMHO a bad idea, and I’m genuinely interested as to why people disagree. 

 

your friendly neighbourhood idiot 

I have no clue why anyone would use anything in NOS mode without using external over sampling. 
 

I send 1536 kHz to the Terminator in NOS mode, using HQPlayer filtering. 

[GoldenOne]

1 minute ago, The Computer Audiophile said:

I have no clue why anyone would use anything in NOS mode without using external over sampling. 
 

I send 1536 kHz to the Terminator in NOS mode, using HQPlayer filtering. 

I think it depends on the device. 

 

I actually really like NOS on the may (which has some analog reconstruction). But on the ares 2 I don't at all (though I don't think it is actually nos as discussed). 

 

It'll be interesting to try nos on the phasure NOS1a if I can actually get it working. At the moment it's an H shaped paperweight

[idiot_savant]

Well, the paper @etanequoted pretty much advocates NOS at 44.1k because it’s too noisy otherwise. I think it’s a thing that people like that I don’t understand.  
 

As I’ve said before, linear interpolates can be a useful tool ( so eg I think Chord use one in the final interpolate ) but not at 44.1k. 
 

IMHO the problem here is that you have a DAC that ( as it stands ) you can set it up to be really quite poor in frequency response terms, then as you increase sample rates via eg HQPlayer it suddenly sounds much better, when it could have been perfectly fine already…

 

your friendly neighbourhood idiot

[GoldenOne]

1 minute ago, idiot_savant said:

Well, the paper @etanequoted pretty much advocates NOS at 44.1k because it’s too noisy otherwise. I think it’s a thing that people like that I don’t understand.  
 

As I’ve said before, linear interpolates can be a useful tool ( so eg I think Chord use one in the final interpolate ) but not at 44.1k. 
 

IMHO the problem here is that you have a DAC that ( as it stands ) you can set it up to be really quite poor in frequency response terms, then as you increase sample rates via eg HQPlayer it suddenly sounds much better, when it could have been perfectly fine already…

 

your friendly neighbourhood idiot

I think technically though if upsampling to 705.6/768mhz then the dac filter itself makes very little difference regardless of design (so long as its not doing something completely crazy). Probably more just a processing power vs benefit question when going from the 768khz source to whatever is actually being fed to the dac

[semente]

VW brought us the emissions-gate. And now we have the NOS-gate.

 

What a strange world.

[idiot_savant]

@GoldenOne you are, of course correct, in that filters should have less effect the higher in sample rate you go, so that brings us back to what is the point of a NOS mode at lower sample rates?

do you happen to know anything about the Holo analogue reconstruction filter? I can’t see it doing much good unless matched with an OS filter?

 

your friendly neighbourhood idiot