Review and Measurements of RME ADI-2 Pro (comparison to ADI-2 DAC)

[amirm]

Hi amirm. Tell me about the graph of jitter. In numbers, how many pico, nano, femto seconds?

Hi there. The jitter is random so not easy to put a number on it from the spectrum display. If I were to guess, it would be in order of picoseconds.

 

[AudioQuality777]

Hi there. The jitter is random so not easy to put a number on it from the spectrum display. If I were to guess, it would be in order of picoseconds.

At least the range from the minimum to the maximum Jitter is possible to write? That is, the average number of picoseconds.

 

[amirm]

You have to compute the area under the red curve here:

It is not easy to do visually .

 

[AudioQuality777]

Yes, it's not at all simple. Thank you.

 

[fredoamigo]

Which is why on this "objectivist" site it would be good to remind ourselves what actually matters and makes a difference to the sound.

I feel like sometimes people chase measurements for the sake of epeen.

So many of the DACs measured here are more than "good enough", sometimes it feels like it may be a disservice to the naive reader to spend so much time obsessing over sub-audible minutiae.

It's cool that we all benefit from Amir's willingness to make full use of his AP, but measuring competently designed DACS these days does feel like a bit of a bikeshedding exercise when compared to things that really move the audible needle, like DSP.

hi
we don't like to know, that what we eat contains chemicals, if they taste the same, chemicals are also invisible... it's the same for an audio device?

it is also very interesting to know the why of the how

 

[dir]

i was suprised that my new adi-2 pro actually has FS signature on the frontpanel despite box&manual shows ordinary Pro

 

[nefilim]

i was suprised that my new adi-2 pro actually has FS signature on the frontpanel despite box&manual shows ordinary Pro

oh cool, when and where did you buy it?

 

[DonH56]

@amirm: Amir, does the AP unit do jitter separation? A good DSO will do it, but the DSO's we have at work cost as much as my house so aren't really practical for private users... A phase noise analyzer or good spectrum analyzer would also do it.

There are zillions of online calculators that will calculate jitter from a phase-noise plot, in this case noise offset from the signal tone, but that may not be the right answer and need care in application and use... In any event here is one: https://www.rf-tools.com/jitter/

 

[amirm]

@amirm: Amir, does the AP unit do jitter separation? A good DSO will do it, but the DSO's we have at work cost as much as my house so aren't really practical for private users... A phase noise analyzer or good spectrum analyzer would also do it.

It can do that given a digital signal. I don't think it can do that on analog, sine wave that is coming out of the DAC.

 

[DonH56]

It can do that given a digital signal. I don't think it can do that on analog, sine wave that is coming out of the DAC.

Hmmm... Jitter is inherently an analog thing but is much easier to derive given a reference like a clock. RF analyzers do it given a fundamental (carrier) frequency (which automated units will infer from the signal amplitude). So I can see why it would not, but OTOH seems like something it should be able to do, maybe with a little user input. Can it output the actual measurement data (sample points)? Then you could use Matlab or something to estimate it for you.

Just what you need, I am sure, something else to do...

Thanks Amir, for this, and the immense amount of time you spend testing and reporting!

 

[Thomas savage]

Hmmm... Jitter is inherently an analog thing but is much easier to derive given a reference like a clock. RF analyzers do it given a fundamental (carrier) frequency (which automated units will infer from the signal amplitude). So I can see why it would not, but OTOH seems like something it should be able to do, maybe with a little user input. Can it output the actual measurement data (sample points)? Then you could use Matlab or something to estimate it for you.

Just what you need, I am sure, something else to do...

Thanks Amir, for this, and the immense amount of time you spend testing and reporting!

@amirm my work van needs a clean when you get a minute...

 

[watchnerd]

hi
we don't like to know, that what we eat contains chemicals, if they taste the same, chemicals are also invisible... it's the same for an audio device?

it is also very interesting to know the why of the how

Sure. But we also need to remind ourselves there is a point at which it won't affect the sound, so over-engineering gives diminishing returns.

 

[amirm]

There are zillions of online calculators that will calculate jitter from a phase-noise plot, in this case noise offset from the signal tone, but that may not be the right answer and need care in application and use... In any event here is one: https://www.rf-tools.com/jitter/

Thanks Don. It was hard to convert the parameters to what it could understand. I did a crude approximation and got this:

The area below -140 shouldn't be there but there doesn't seem to be a way to cut that off. So the 250 ps of jitter is likely exaggerated by 1/2 or so.

 

[amirm]

@amirm my work van needs a clean when you get a minute...

I don't clean horses!!!

 

[DonH56]

Thanks Don. It was hard to convert the parameters to what it could understand. I did a crude approximation and got this:

<figure elided>

The area below -140 shouldn't be there but there doesn't seem to be a way to cut that off. So the 250 ps of jitter is likely exaggerated by 1/2 or so.

That seems way high but I am getting ready for a funeral so will have to loop back later. I also have a spreadsheet around, somewhere, that may make it easier to analyze. As you say it may be hard to use an RF-oriented online calculator for this.

 

[dir]

oh cool, when and where did you buy it?

it comes from local Ukraine dealer
i was compare both: DAC and Pro versions
it was not easy because they have different stage of gain
also it seemed to me that the character of the sound was varied (more or less dynamic) depending on the setting of amplification on output. maybe its just a psychoacoustic myth (because measurments stay same), maybe its just a tricky games with digital volume or may be due to the input sensitivity of my power amplifier and AV-receiver. But it was really interesting experience like choosing between different CD-players or sorts of mastering.
In general, I found the sound on both devices are really nice - transparent, detailed but quite musical + very flexible features

 

[NTTY]

Thanks for this review. It made me pull the trigger on the ADI2-DAC

 

[Rod]

Thanks for this review. It made me pull the trigger on the ADI2-DAC

I am not regretting my decision to buy it. That eq will come in handy. I found out on my headphones that the edginess on my hd-400i was due to a peak of 10db at 8.5k. Dialed that down and the vocals smoothed without having a negative effect on the overall sound. Much better than the eq software that I tried in the past.

 

[NTTY]

That's indeed one of the many reasons why I went for it.
That said, EQ is disabled when playing DSD. So, at the same time, it was not a critical feature for me to have

 

[Krunok]

Conclusions
From the measurements, it seems clear that the RME ADI-2 DAC is very much improved over the ADI-2 Pro. This was unexpected. For audiophiles this is good news seeing how the DAC version is much cheaper anyway. For pros though, it seems like a loss to have a less performant DAC in the ADI-2 Pro subsystem.

This leaves me personally in a quandary of not having a reference class DAC when I return the ADI-2 DAC to its owner tomorrow.

Shall we say that, in your opinion, the Pro FS version of this DAC is "as good as it gets"?

BTW, does Pro FS version support remote control?