XXHighEnd

Take the following with a big pinch of salt...

When I was 'testing' the Sonore microRendu with the iFi Nano DAC a few months ago I took a few 24/192 captures. Here are two spectra - the same track, with and without the Intona.

I'll do some more in-depth testing at some point to see if this is actually repeatable.

Mani.

I've just found a couple of other files. Here's what silence* looks like with and without the Intona...

*Edit: Playing back the 'digital silence' file from the Alan Parsons test CD.

Mani.

And finally, in case it's of interest, silence with the Intona feeding the NOS1a...

[The rise in noise after 45kHz is down purely to the ADC and not the DAC.]

Mani.

Hi Mani,

Thanks for these graphs - very interesting !

For what I understood when I got the Intona:
- Cut noise with galvanic isolation.
- Also cut a possible ground loop (and I was able to verify that because I was having one before my upgrade to NOS1a).

Nothing technical about what I am saying but if the Intona is helping with cutting noise, maybe with build 14393 what we interpret as "very accurate" or "sharp" is not really about that and it turns a good thing into something else...

Alain

Hi Alain, in your case the Intona has cut the ground loop by providing galvanic isolation - that's exactly what galvanic isolation means. Galvanic isolation does not necessarily lead to noise reduction - a common misconception. (But if you're using an isolation transformer, it probably does cut HF noise - unfortunately, it'll kill transients in the music too. This has been my experience anyway.)

Now looking at my iFi DAC graphs (not the NOS1a, because there's no with/without Intona), it's clear that the Intona is cutting noise, as well as providing galvanic isolation. So to my mind, the Intona does more than just providing galvanic isolation. Maybe some of what it does is actually destructive to the sound? Robocop seams to hear this, but for me it's exactly the opposite. To me, the Intona cleans things up, making music sound simply more realistic.

Anyway, this has inspired me to test things further with the NOS1a, with and without the Intona. I'll capture some digital black files and also a couple of 1kHz @-90dB files. If anyone can think of any other tests I could perform, just let me know.

Mani.

Hi Mani,

Very nice initiative. And I am afraid it sprung from my text :


but my "technically" was not meant as in "measuring". Instead, I tried to refer to "nicer highs" or "better bass" or other kinds of what I call technical reference (as in technical listening).

So just in case : of course the Intona can be measured for noise (like 8KHz, might you be able to focus on that). And then especially for non-isolated D/A converters (so take a normal NOS1 and you will see a difference as well).

Otherwise, please continue !
Regards,
Peter

PS: And what I said in the other thread : the Intona makes things right (more real); I just have no other description for it. But this would take the NOS1a for granted and I can't testify for other DACs.

Unfortunately, it seems my ADC simply isn't good enough to measure whether the Intona makes a difference or not... with the NOS1a, that is  :(

But on the plus side, the NOS1a really is quiet  :)

Mani.

Remember the graphs on cables. Are not what we hear.

The actual differences are quite small between Intona and no Intona whether we can hear them is another story.

I can state the Intona does make a difference but how correct is this in our systems.

I do need to go back to 10586 and try Intona.

In reality Intona is designed for industrial setups and no consideration for audio listening. There is a place for using this technology in audio but it needs more work which I guess is what Peter is working on. But ultimately it should be in the DAC and not another box.

Robert

:thanks:


Haha, this is not correct. That is, it would be useless to put that in the DAC. And for example. For the NOS1a it *is* in the DAC. But logically, it is now after the receiver. "Logically" because we're in the DAC anyway. So the only usecase for an application like this would be at the other side of the input connector. Well, then do it outside, that saves you a trip to the electronic repair store.
Understand ?

What I'm also saying with this, is that what's in the NOS1a is another "application" as such. It also galvanically isolates, but it is in another position in the chain.

Regards,
Peter

Hi Mani,

What are "digital black" files ? I can imagine something, but looking at the result of that ... I don't know. Especially not when comparing that to silence (could be the same) and even more especially not when comparing that to playback at -90dBFS through the NOS1a, which looks totally different and/but (!) normal to me.

Thanks !
Peter

Yes, we should always bear this in mind.

Mani.

'Digital Black' is track 95 on the Alan Parsons Sound Check 2 CD. He describes it as "silence - all bits at 0". Yes, my 'digital black' and 'silence' graphs look almost* identical. With the former, I am playing back the digital black file on XX. With the latter, nothing is playing back (but the NOS1a is still connected to the ADC).

(*There is a curious spike at 46kHz, only visible when a file is being played back, i.e. not present in my 'silence' graphs. This spike actually seems larger with the Intona in place. But this needs to be taken with a pinch of salt because it may simply be a quirk of the ADC.)

So all in all, another 'failed' experiment. I'm starting to appreciate how Edison must have felt...

Mani.

Why ??

Anyway, I still don't understand why silence(/black) looks so strange for that noise floor, vs. playing that -90dBFS signal which looks fine for noise floor ...

Peter

Hi Mani,

Thanks for the precision and the additional graphs :) The comparison with and without Intona with the NOS1a seems to show very little differences...

I am not at home presently but hope to be able to do some listening comparisons.

I still have to verify what will happen with that previous ground loop...

Alain