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Denafrips DACs might not actually be NOS?


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  • 4 weeks later...

@GoldenOne - ooh, graphs! Could you grab a wideband FFT of it playing the impulse track?

 

And I'm not sure I'm following the impulse response derived from the transfer function - is this the continuous sweep thingy? I know that some manufacturers deliberately detect impulses, and effectively turn off the filter to protect their coefficients - but that shouldn't be happening in NOS mode? From the measurements in Stereophile, that didn't appear to be the case at that time, so maybe it's a measurement artefact?

 

 

 

your friendly neighbourhood idiot

 

 

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Interesting - this is almost certainly *not* processing delay as the only way you'd get this much ( 40ms ) is thousands of taps, which isn't backed up by the stereophile measurements.

I'm sure @GoldenOne would love an excuse to measure with his shiny AP?

If I had to put money on it, I'd say there's some kind of FIFO scheme in there. Hmmm, this might be interesting - I reckon the AP can measure group delay, and then graph that over time ( like minutes ) - do you fancy this?

 

 

 

your friendly neighbourhood idiot

 

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1 minute ago, idiot_savant said:

Interesting - this is almost certainly *not* processing delay as the only way you'd get this much ( 40ms ) is thousands of taps, which isn't backed up by the stereophile measurements.

I'm sure @GoldenOne would love an excuse to measure with his shiny AP?

If I had to put money on it, I'd say there's some kind of FIFO scheme in there. Hmmm, this might be interesting - I reckon the AP can measure group delay, and then graph that over time ( like minutes ) - do you fancy this?

 

 

 

your friendly neighbourhood idiot

 

The AP has a DUT delay test so I'll run that in a sec (currently rendering a video so might need to wait a bit).

Also the AP isn't mine it's just being loaned to me temporarily. Still a while off getting one permanently but working towards it.

https://youtube.com/goldensound

Roon -> HQPlayer -> SMS200 Ultra/SPS500 -> Holo Audio May (Wildism Edition) -> Holo Audio Serene (Wildism Edition) -> Benchmark AHB2 -> Hifiman Susvara

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If possible, using the same input as Darko ( i.e. Toslink? ) - although I think AES would do.

 

Should think the loan unit has got you salivating for your own!

 

Although didn't JA at Stereophile have his AP loaned from them for years and years?

 

 

 

your friendly neighbourhood idiot

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2 minutes ago, idiot_savant said:

If possible, using the same input as Darko ( i.e. Toslink? ) - although I think AES would do.

 

Should think the loan unit has got you salivating for your own!

 

Although didn't JA at Stereophile have his AP loaned from them for years and years?

 

 

 

your friendly neighbourhood idiot

It most definitely has!
Using it it's immediately clear why AP is the industry standard. It's almost nothing to do with the performance, it's the combination of hardware and software flexibility and how even custom, complex tests can be set up and run in a matter of seconds. It's immensely powerful.

I'm not sure what JA's arrangement was. But a large publication like stereophile is likely a fairly different sort of deal than a moderately sized youtube channel.
At the moment my intention is to purchase one as soon as funds are available. I'm looking at if it would be possible to get one on a hire-purchase scheme as that'd make things much easier but being a new business and me personally being quite young it's unlikely.

This unit has been kindly loaned to me for a couple weeks by AP to check that it will do everything I need it to do (and to fully sell me on it of course in case I had any doubt. With something as impressive as this a hands-on test really does let the device sell itself).

I'll ask them if there is any possibility of being able to keep ahold of a unit, maybe even sort out some sort of sponsorship arrangement. But honestly the tricky thing is that AP really doesn't need it. They're the industry standard for a reason and anyone who might need an AP already knows them. I doubt they need much advertising and given the cost of the device I doubt they'd see the value in it. Stereophile MAYBE, ASR paid RRP, and so I can't imagine I'd be much different.

In any case, I'm determined to get one. I don't know exactly when it'll happen, but as soon as I'm able to do so I will.

https://youtube.com/goldensound

Roon -> HQPlayer -> SMS200 Ultra/SPS500 -> Holo Audio May (Wildism Edition) -> Holo Audio Serene (Wildism Edition) -> Benchmark AHB2 -> Hifiman Susvara

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One of the things I'm hearing with the Ares II on USB input is that there is a treble filter like effect inversely related to sample rate... CD rate sounds rolled off but as you increase

native sample rate the perceived treble response become more linear. Very noticeable on instruments like cymbals

Regards,

Dave

 

Audio system

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1 hour ago, idiot_savant said:

Interesting - this is almost certainly *not* processing delay as the only way you'd get this much ( 40ms ) is thousands of taps, which isn't backed up by the stereophile measurements.

I'm sure @GoldenOne would love an excuse to measure with his shiny AP?

If I had to put money on it, I'd say there's some kind of FIFO scheme in there. Hmmm, this might be interesting - I reckon the AP can measure group delay, and then graph that over time ( like minutes ) - do you fancy this?

 

 

 

your friendly neighbourhood idiot

 

Ares 2 OS and NOS have near identical delay. The values shown are consistent and did not change from run to run.

gkFu382NaK.thumb.png.0dee566a2d5eb18fa4837806166d33bc.pngomtPcav4ds.thumb.png.66807db3067fcf7f6da4b514053be818.png

ifi iDSD diablo for a quick comparison:

2MYZTiLBR7.thumb.png.6510e1dbdc8e2e9069ee4fca978cf07f.png


So yes, it seems that the Ares 2 does indeed have a notable delay. Nothing 'huge', but definitely enough to throw off a movie audio sync.
The above were taken using SPDIF given as that is what Darko used.
USB may be slightly higher if there is an additional buffer there. (Can't test that with the AP)

https://youtube.com/goldensound

Roon -> HQPlayer -> SMS200 Ultra/SPS500 -> Holo Audio May (Wildism Edition) -> Holo Audio Serene (Wildism Edition) -> Benchmark AHB2 -> Hifiman Susvara

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46 minutes ago, idiot_savant said:

@davide256 -are you using NOS mode? If so, are you feeding it straight 44.1k?

The thinking so far is that the linear interpolate it appears to be doing would give you exactly that ( 6dB of attenuation at 20k for 44.1k )

 

 

your friendly neighbourhood idiot 

Yes to NOS mode. Don’t want more oversampling added to HQPlayer or PGGB files. This would also explain why my Linn Genki CDP sounds rolled off in the treble through coax

Regards,

Dave

 

Audio system

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1 hour ago, idiot_savant said:

@GoldenOne- can you maybe leave it running for a bit? We seems to have a 20ms or so discrepancy - I’m interested if the delay changes over time?

 

 

 

Your friendly neighbourhood idiot

Well it's a good thing you said this!
I just connected it again via coax this time. I was getting ~25ms at first, but I just checked again 2 mins later aaaand:

image.thumb.png.aa19cc140c3814d7b9f14d1ca777bab2.png

Thank you for suggesting that!
I'll leave it connected for a bit and try again shortly.

Why is it do you think that it gets longer after a while?

https://youtube.com/goldensound

Roon -> HQPlayer -> SMS200 Ultra/SPS500 -> Holo Audio May (Wildism Edition) -> Holo Audio Serene (Wildism Edition) -> Benchmark AHB2 -> Hifiman Susvara

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I don't have the option to do a DUT delay/time test setup so am just running it manually every few mins, but it is steadily getting longer.

Currently at 129.8.

I'm gonna go grab some food then will see what it's at once I'm back!

https://youtube.com/goldensound

Roon -> HQPlayer -> SMS200 Ultra/SPS500 -> Holo Audio May (Wildism Edition) -> Holo Audio Serene (Wildism Edition) -> Benchmark AHB2 -> Hifiman Susvara

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4 hours ago, numlog said:

Might be interesting to see if 32x steps are visible in OS mode with different input data rates, that would probably indicate if there is any difference between NOS and OS mode when fed 1.4Mhz data, and if it is capped at 1.4Mhz.

Stepping behaviour is indeed visible in OS mode.
WRDe9I7wda.thumb.png.e192ba609638b9b3cd125e6f66b358cb.png
Tlwc9biTcK.thumb.png.894a6c4cf04aa9e248e7b2bbe0266798.png

 

https://youtube.com/goldensound

Roon -> HQPlayer -> SMS200 Ultra/SPS500 -> Holo Audio May (Wildism Edition) -> Holo Audio Serene (Wildism Edition) -> Benchmark AHB2 -> Hifiman Susvara

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Ok so the delay seems to be....somewhat random, but also sloowly gets longer over time (not sure if there is a cap as such but we will see!)

First go: 25ms, moves to 129ms after a while
Unplug, move to coax 2: 85ms
Unplug, move to coax 1: 81ms
Swap back to optical: 163ms
Swap back to coax: 140ms

Leaving it on the coax now and will do for a short while.
140.5ms currently

https://youtube.com/goldensound

Roon -> HQPlayer -> SMS200 Ultra/SPS500 -> Holo Audio May (Wildism Edition) -> Holo Audio Serene (Wildism Edition) -> Benchmark AHB2 -> Hifiman Susvara

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I'm wondering if the variable delay has something to do with their invincible PLL? If PLL is off does the delay revert to a stable number?

 

The Mola-mola DAC I understand also has a somewhat variable delay but not one which changes over time. Just each time it locks the delay is indeterminate. This I gleaned from posts by one early adopter over at WBF.

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23 minutes ago, opus101 said:

I'm wondering if the variable delay has something to do with their invincible PLL? If PLL is off does the delay revert to a stable number?

 

The Mola-mola DAC I understand also has a somewhat variable delay but not one which changes over time. Just each time it locks the delay is indeterminate. This I gleaned from posts by one early adopter over at WBF.

It shouldn't do.
PLL shouldn't add any latency. A buffer or DSP would though.

Holo may latency for comparison with PLL on (blurred bottom result cause only one channel was connected):image.thumb.png.308cc17dd31d33629ba7931d586d35c1.png
 

https://youtube.com/goldensound

Roon -> HQPlayer -> SMS200 Ultra/SPS500 -> Holo Audio May (Wildism Edition) -> Holo Audio Serene (Wildism Edition) -> Benchmark AHB2 -> Hifiman Susvara

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13 minutes ago, GoldenOne said:

PLL shouldn't add any latency. A buffer or DSP would though.
 

 

I was using 'PLL' here to refer to the whole frequency locking system. They may be using a buffer to allow them to get more jitter rejection. The PLL is likely a digital one (DPLL).

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