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Review and Measurements of Allo DigiOne RPI S/PDIF

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#21
Hey Johan I've nothing to sell. I personnally use Roon with dual pc as source.

I was using digione home and i have 2 friends with digione (I'm not talking about signature here) and I compared with them Digione/DP3
In both system DP3 sounded better to our ears (4 different people).
one is:
etalon isolator RJ45---Audioquest Vodka rj45--- Digione or DP3---coax thot cable--- AudioGD Dac 19---AudioGD master10---PEL Alycastre S2 speakers

So I'm curious about DP3 measurements since Digione as also extremely good measures.
Maybe there is not only jitter to consider??? I don't know
 

johan

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#22
Hi Renan

I understand you have nothing to sell and that you consider this system better. Please note that many people find some types of distortion pleasant as sound.

I am not saying that your particular streamer has jitter , I am just pointing out that Digione and Sig have jitter thats close to the floor of measuring equipment . I cannot answer the question of " maybe there is something else except jitter" since this is called audiosciencereview :)

I also note that you are using a AudioGD Dac 19

Not sure if you are aware , but AudioGD DACs have been tested here on the forum and it has very low THD+N. I cannot find measurements of your particular DAC but like most R2R (including Soreen ) they have poor measurements (while being reputed to sound good) . It shows , again , that distortion is pleasant to the ears.

https://www.audiosciencereview.com/...d-nfb-27-38-dac-and-headphone-amplifier.2486/
https://www.audiosciencereview.com/...audio-gd-nfb28-28-dac-and-headphone-amp.5147/


In the end you like your streamer . I doubt that it will reach the jitter of Digione , but maybe, like you said, maybe it has something else that makes it sound good :).
I don't mean so sound dismissive , its just that everyone hears different things . Jitter wise , I think Digione will perform better.

PS .I found the DAC 19 measurements https://www.superbestaudiofriends.org/index.php?threads/audio-gd-s19-technical-measurements.4305/
Thats about -45db THD+N.
 
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#23
Yes sound quality will depend on taste of people and measurement of Jitter is just a fact. This is why I'm curious about the jitter in DP3 considering what i heard from it.

if I follow your reasoning, the digione signature can not be better than the digione since the measurements of the jitter for the digione are already at the bottom of what we can measure?
Is that the case? ?

Considering the difference in souund, I never saw that a larger soundstage is due to distorsion. Usually I get larger soundstage if I do some phase correction or crosstalk cancelation....
 

johan

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#24
Renan33 ,

In fact I have designed a DAC with a THD+N of -110 and tweaked the output stage and increased distortion to -100 and everyone has the exact same impression..sound stage is larger.

To answer your question , yes definitely increased distortion can be perceived as wider soundstage.

As I said in the beginning , I don't mean to dismiss what you hear. Your streamer seems to work better on your dac .

Enjoy.
 
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#25
Well we are just talking "science fiction " there since there is no measure of DP3 jitter.

You might consider that DP3 could also present a very low jitter.

Ok for your experience on distorsion and sound stage... I was not aware that distorsion could wider the sound stage...

Our comparison for DO/DP3 has also been done with a 1451 Soekris Dac (R2R). By the way the Dac19 is not the R2R version but a former one.

There is difference between the Dac with a sound more natural and to some point flat with Soekris and with more medium in front bor the audioGD dac 19. So I don't know which Dac is more distorded but the the comparison of DO/DP3 gave us the same filling.

I have a DO since it was on the market and I recommended to many people the DO. So I'm fully convince about what it improve in different systems.
For me the use as Roon end point is perfect and I cannot do this with the DP3. So let say that suddenly i got a taste for distorsion coming back.....

Finally, you did not answer me, if the DO is so low in jitter... what you really improve with the DO signature....??
 

franklin

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#30
Hi Amirm,

Could you test the digiones with wifi on , let say playing a file on Roon with wifi ?
I am curious is there any measurement change when a RF transmission is working.
I think many people want to know this too.
 

amirm

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#31
Hi Amirm,

Could you test the digiones with wifi on , let say playing a file on Roon with wifi ?
I am curious is there any measurement change when a RF transmission is working.
I think many people want to know this too.
Can do. I have a lot on my plate right now so remind me in a week or two if I don't get it done.
 
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#32
Thanks Amir.
I was one of the people who originally requested this so am very grateful. It does seem to be a bit of a moot point as to whether the Signature is really better or not (not just appreciably but better at all since it appears worse on some measures). I would be intrigued as to how bad a dac one would need for the output to be appreciably different between them. Of the top of my head I imagine it would have to have a really good conversion clock and a really poor s/pdif input not to swamp any differences
 

MZKM

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#33
RMS level of jitter is 73 picoseconds.

That’s about 18Bit of dynamic range (10^12 / [48000 * 2^18]= 79 psec).

So, since jitter in practice is dealing with time delay and the J-test uses frequencies, can we use any of these measurements to state what the equivalent picosecond or nanosecond amount of jitter the J-test is using?
 

amirm

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#34
So, since jitter in practice is dealing with time delay and the J-test uses frequencies, can we use any of these measurements to state what the equivalent picosecond or nanosecond amount of jitter the J-test is using?
We can only compute that for simple sinusoidal jitter. For other spectrums including the combination of jitter sources as we commonly see, the math becomes non-trivial. For sinusoidal jitter, 73 RMS picoseconds translates into distortion spikes that are -114 db down or 19 bits.

As I commented earlier, I don't think the jitter meter in AP goes much lower than that. I would trust the spectrum more than the single figure.
 

MZKM

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#35
Next, to get really calibrated, I thought I test the Topping D10 as a S/PDIF interface bridge from USB:


Starting with FFT on top right, we immediately see the 250 Hz square wave in J-test becoming visible as jitter. 250 Hz is a square wave so when decomposed into frequencies, we see it and all of its odd haromonics (250, 750, 1250, etc). So we clearly have data dependency in the S/PDIF output of the Topping D10.

We see the same in scope display on the left where the sine wave pattern of the 250 Hz harmonics are clearly visible. The waveform does not look random as it did with APx555 output. RMS jitter has risen to 126 picoseconds and peak is nearly double at 400 ps. Jitter SINAD as dropped to 11 dB.
Can you explain the difference between this picosecond measurement and this one:

 

amirm

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#36
Can you explain the difference between this picosecond measurement and this one:
That one has much higher resolution FFT. And it has a 700 Hz high pass filter from what I recall.
 

MZKM

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#37
That one has much higher resolution FFT. And it has a 700 Hz high pass filter from what I recall.
Makes sense,

So, would you say ~127psec is a correct description?

I’m asking because I mentioned your measurements of the iFi Purifier and how it only really mattered with high amounts of jitter (which you had to induce) and that it added noise of its own, then since he had it on hand as he uses it, he measured it himself and showed about 100psec of jitter (If it’s the same as how he tested his own Synchro-Mesh: “Measurements were done with Sonos driving the SM using a Standard BNC cable and using a Standard BNC cable from SM to the Scope. Powered by the supplied 9V Wall-Wart”). I also wonder how his setup is able to measure jitter down <30psec (he claims his own SM can get down to 7psec) when the inherent jitter of your AP is >60psec.

EDIT: I also don’t get the SINAD of <12dB, as even with the peak jitter of ~400psec, that’s still 14dB-15dB depending on sampling rate, unless there are other things contributing to the lower score.
 
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Empirical Audio

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#39
MZKM - I measure 7psec of jitter by DIRECTLY measuring the jitter. I never use a DAC to measure jitter of a digital output device because the DAC itself introduces more jitter. I use a 7GHz B/W scope with a Jitter measuring system. It samples the period of the data waveform as the music is playing and displays all of the sample measurements of the period in a histogram. I can believe that the AP system cannot measure really low jitter. The B/W is not high enough.

Here is how the SPDIF iPurifier compares to my reclocker:

https://www.audiocircle.com/index.php?topic=157348.msg1727698#msg1727698

iPurifier is a very good re-clocker and I own 4 of them, used in my HT system for Dolby Digital jitter reduction.

Steve N.
 
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