Bits is bits?

[Ralf11]

32 minutes ago, jabbr said:

Thankfully our brains (like digital systems) have good pattern matching error correction  

 

Agreed, but there is often a fine line between pattern recognition, and pattern imposition.

[kumakuma]

12 minutes ago, fas42 said:

In the end, we just want the music to sound good ... if someone is happy with the results using an approach that has me scratching my head about it, I'm not going to suggest that he should undo it, just because it's not my way, .

 

 

Really? After 5000+ posts telling us that our approach to this hobby is all wrong?

 

[jabbr]

13 minutes ago, Ralf11 said:

 

Agreed, but there is often a fine line between pattern recognition, and pattern imposition.

 

Like making everything either a 1 or a 0, a truth or a false?

[Ralf11]

I was thinking about hallucinations, which are appropriate for this site.  It also applies to making a mistake with respect to predator detection, which has more severe consequences.

 

Or just fuzzy logic - also relevant on this site...

[jabbr]

Both!

[fas42]

20 minutes ago, kumakuma said:

 

 

Really? After 5000+ posts telling us that our approach to this hobby is all wrong?

 

 

All wrong? I've heard systems in person, on very rare occasions, that get it mighty right - but the logic behind why the particular rig is doing so well is not anywhere as well thought through. If people were to do a few experiments with setups that were very close to achieving high standards of SQ, in the sorts of ways I've mentioned, then I would suggest that many would hear the variations in the sound - and that could give them a different focus in how they proceed.

 

Most people are aware of how impressive the playback of a recording that they thought they knew well can come across - when they hear it on a "special rig" ... what I'm saying is that at that moment one is finally hearing the actual content of the recording, without almost no added signature of the playback system, for the first time. If an approach is used that doesn't consider that as a goal, then, yes, I suppose I would say it's "all wrong" ...

[jabbr]

4 minutes ago, fas42 said:

Most people are aware of how impressive the playback of a recording that they thought they knew well can come across - when they hear it on a "special rig" ... what I'm saying is that at that moment one is finally hearing the actual content of the recording, without almost no added signature of the playback system, for the first time. If an approach is used that doesn't consider that as a goal, then, yes, I suppose I would say it's "all wrong" ...

 

This is the same post you use to respond to every thread, and has no relationship to the topic of this thread, nor does it to the topic of many other threads you post to. You have your own thread that you are free to post to. 

[Ralf11]

Frank has verbal incontinence

[fas42]

13 minutes ago, jabbr said:

.. , and has no relationship to the topic of this thread, ...

 

I would suggest people are unable to remember what the content of that article is ... they are so obsessed with trying to pinpoint where the merchandising of snake oil starts, that their eyes glaze over as the second sentence passes by, "It’s never long before someone invokes the “bits are always bits” argument, whining that digital is either “on or off”, and so there can’t be a “better” digital signal—it is 100 % perfect or not working at all." ...

 

As the rest of the article intelligently notes, there are plenty of areas where the "perfection of digital" comes undone, when that nasty ol' analogue world, just close by, has to get involved - pretending that this can't be relevant might be a nice comfort blanket; but that doesn't help those who just want better sound.

[kumakuma]

1 hour ago, fas42 said:

 

I would suggest people are unable to remember what the content of that article is ... they are so obsessed with trying to pinpoint where the merchandising of snake oil starts, that their eyes glaze over as the second sentence passes by, "It’s never long before someone invokes the “bits are always bits” argument, whining that digital is either “on or off”, and so there can’t be a “better” digital signal—it is 100 % perfect or not working at all." ...

 

As the rest of the article intelligently notes, there are plenty of areas where the "perfection of digital" comes undone, when that nasty ol' analogue world, just close by, has to get involved - pretending that this can't be relevant might be a nice comfort blanket; but that doesn't help those who just want better sound.

 

Yes, but that isn't what you have been posting about.

 

In fact, as far as I can tell, you have zero experience with the subject of the article as you don't even own a DAC except the one in your CD player.

[Rexp]

In a system where chain is phone>upnp streamer>dac. Why does Tidal app sound inferior to mconnect app, given same bits? 

[esldude]

21 minutes ago, Rexp said:

In a system where chain is phone>upnp streamer>dac. Why does Tidal app sound inferior to mconnect app, given same bits? 

Does it sound different?

[marce]

7 hours ago, fas42 said:

 

 

As the rest of the article intelligently notes, there are plenty of areas where the "perfection of digital" comes undone, when that nasty ol' analogue world, just close by, has to get involved - pretending that this can't be relevant might be a nice comfort blanket; but that doesn't help those who just want better sound.

Where? What?

[marce]

5 hours ago, Rexp said:

In a system where chain is phone>upnp streamer>dac. Why does Tidal app sound inferior to mconnect app, given same bits? 

Do you know the same bit pattern is being put out, is there digital volume control involved and of course as put, do they sound different all things to investigate...

[mansr]

11 hours ago, jabbr said:

The Pro-next S2D is an outstanding and affordable bus powered DAC that I have found sensitive to power supply in certain situations. My personal experience. 

If it's that sensitive to the power supply, I wouldn't call it outstanding.

 

11 hours ago, jabbr said:

I’ve seen the minimum rise time specified at 300 ps with a max roughly 1 ns according to the eye diagram (which itself places no lower limit on rise time).

Wherever you saw the 300 ps figure, it was wrong.

 

11 hours ago, jabbr said:

Obviously we expect the interface to have a low BER, but again, if there is no effect of variations in rise time (within spec) on the interface’s I2S/DSD eye plot itself then this is a nonissue.

The I2S timing is mostly irrelevant since the DAC chip buffers the data internally.

[marce]

USB 2 rise times:

Low Speed 75-300ns    Fknee approx.  4.66MHz  to 1.16MHz

Full Speed   4-20ns       Fknee approx.  87.5MHz to 17.5MHz

High Speed 100ps        Fknee approx.  3.5GHz

 

 

[mansr]

2 minutes ago, marce said:

USB 2 rise times:

Low Speed 75-300ns    Fknee approx.  4.66MHz  to 1.16MHz

Full Speed   4-20ns       Fknee approx.  87.5MHz to 17.5MHz

High Speed 100ps        Fknee approx.  3.5GHz

Where are you getting that 100 ps figure? The spec (section 7.1.2.2) says 500 ps.

[marce]

 A Fairchild app note.  Found it in Table 7.8 in the USB 2 spec, yep 500ps (so 0.70GHz) though 100ps looked a bit fast...

[jabbr]

4 hours ago, mansr said:

If it's that sensitive to the power supply, I wouldn't call it outstanding.

 

I see. Lots of other folks like it. 

 

4 hours ago, mansr said:

 

Wherever you saw the 300 ps figure, it was wrong.

 

Let’s see 🤔

 

https://www.usb.org/sites/default/files/USB_2_0_Electrical_Compliance_Specificationv1.06.pdf

 

3.2 EL_6

 

 

4 hours ago, mansr said:

 

The I2S timing is mostly irrelevant since the DAC chip buffers the data internally.

 

Which DAC chip ... all of them, in all cases? What about chipless DACs ... point being that if the USB variation doesn’t make it onto the I2S/DSD lines then it can’t make a difference. That’s not saying that it always makes s difference. Those aren’t the same thing.

[jabbr]

3 hours ago, marce said:

 

High Speed 100ps        Fknee approx.  3.5GHz

 

 

 

I believe these are the recommended specs for the oscilloscope used to test the USB signal for more accurate eye-patterns.

[mansr]

9 minutes ago, jabbr said:

I see. Lots of other folks like it. 

So what? Some people like vinyl.

 

9 minutes ago, jabbr said:

Let’s see 🤔

 

https://www.usb.org/sites/default/files/USB_2_0_Electrical_Compliance_Specificationv1.06.pdf

 

3.2 EL_6

The section of the USB 2.0 specification referenced there says 500 ps.

 

9 minutes ago, jabbr said:

Which DAC chip ... all of them, in all cases?

All modern ones do. Old, non-oversampling DACs like the TDA154x chips have only a minimal deserialisation with the LR clock directly driving the conversion stage. These chips have so poor performance at the best of times that I doubt the differences you're looking for would be detectable below all the inherent noise and distortion.

 

9 minutes ago, jabbr said:

What about chipless DACs

Those are a joke.

 

9 minutes ago, jabbr said:

... point being that if the USB variation doesn’t make it onto the I2S/DSD lines then it can’t make a difference. That’s not saying that it always makes s difference. Those aren’t the same thing.

Fair enough.

[jabbr]

16 minutes ago, mansr said:

So what? Some people like vinyl.

 

The section of the USB 2.0 specification referenced there says 500 ps.

Perhaps too fast a rise time causes your eyes to jitter

 

In any case your post is riddled with subjective opinions. 

 

Perhaps certain cables slow the rise time and this helps out certain USB receivers, I don’t know either way. 

[mansr]

15 minutes ago, jabbr said:

Let's uncrop that screenshot a little:

 

Now look up the reference mentioned there, USB 2.0 Specification Section 7.1.2.2:

 

Note how it very clearly states that the minimum rise time is 500 ps. Yes, there is a discrepancy. Since the Electrical Compliance document refers to the USB 2.0 Specification, the latter reasonably takes precedence here.

[Ralf11]

Does the discrepancy mean I will need glasses for my eye diagram?

[marce]

I think this should be an interesting intro to SI...

https://www.keysight.com/upload/cmc_upload/All/GTL84.pdf

 

 

Monotonic rising and falling edges are critical....