Blue or red pill?

[sandyk]

25 minutes ago, fas42 said:

 

Sometimes it can be easy to pick the obvious signs of non-optimised programming - on the laptop, the "poor" performers were constantly driving the physical media throughout the track, and chewing up significant CPU cycles - Media Monkey, which turned out best, buffered like crazy initially - and then ignored the drive; and the CPU effectively went to sleep during the replay ... the effort had been made to tune the software to just do the job it had to do, well - by not disturbing the rest of the system any more than necessary.

 

Mansr knows that far better than most.

What we need is for highly qualified members like Mansr and Archimago to see (hopefully) from listening results by members like Mani, that there are still some unexplained areas where current theory doesn't quite cut it, and carry out further investigations.

 

[sandyk]

5 minutes ago, mansr said:

Wrong. When reading from a storage device, the data is placed in RAM (system memory). The USB controller then retrieves the data from the same RAM when sending it to the DAC. In a normal computer, there is no way to bypass the RAM buffer, nor is there any reason to do so.

 

Well, looks like all the members who pestered jRiver must be wrong, and my own (and others) observations based on the activity LED of the USB memory stick are wrong too !

Using cPlay, as I described, there is a delay before playing starts with the activity LED flashing , then when  play starts the LED stops flashing and the USB memory stick can be removed. With other programs such as .VLC Media player etc. where the activity LED continues to flash while playing, you can  NOT remove the USB memory stick without play stopping.

There is obviously something very different happening.

In this case , I believe that Frank summed it up nicely. He pointed out all the extra activity going on which could change the noise profile.

So you are claiming that playing a file from System Memory using certain programs is all BS ?

I doubt that you will have a great deal of support for that claim.

[sandyk]

30 minutes ago, kumakuma said:

 

As mansr said, files are always played from system memory.

 

What you're referring to is whether or not the program loads the entire track or just part of the track into system memory before starting playback.

 

As fas42 pointed out , this results in a great deal more unnecessary processor etc. activity. and most members appear to prefer the sound without all this extra RF/EMI and HDD/SSD activity. The lower the noise generated at the time of playback results in improved performance in the DAC .

You may not be able to hear the difference, but I sure can.

Next you will be trying to tell me that playing music with Power DVD etc. , or even from a sound editing programs sounds just as good as a file that has been played solely from System Memory using a dedicated Audio software player ?

Dream on ! 

 

 P.S.

 Please also note the comments made attributed to jRiver in a recent post.

[sandyk]

40 minutes ago, kumakuma said:

 

Not sure how you got that from what I wrote

 Based on previous discussions with you !

[sandyk]

36 minutes ago, mansr said:

I don't know what PowerDVD does, but editing programs generally keep as much as possible in memory.

 The audio from Media players such as Power DVD, VLC Media player and GOM, while perhaps acceptable due to their video capabilities, sound quite lacklustre in comparison with the same audio (after extraction by demuxing) from a dedicated Audio SW player.

 Neither does Sound Forge F9 or Audacity sound as good either.

[sandyk]

36 minutes ago, esldude said:

If so, yes the first two runs were less than optimum, and the third one would have been the way to do it.  You have a fresh reference that way. 

 

 Dennis

 Yes, ideally you need some kind of reference. After quite a few repetitions, everything starts to sound the same.

 

Years ago, a friend had me perform a test with 3 x 20 pairs of  comparison files with the order changed randomly with a computer program he wrote.  He had taken my files and made up 3 new folders on a USB memory stick after shuffling them around between 2  HDDs on his PC, but none of his copies sounded as good as I remembered them sounding.

I then inserted a fresh copy of the better sounding tracks into each of the pairs as a reference, (a total of 3 tracks) which then helped me to home in on which of the original tracks had been my original preferred copy.

I had a falling out with my friend (DIY Audio member Greg Erskine) however, when I insisted that NONE of his tracks sounded as good as the new reference track.

 

Alex

 

 

[sandyk]

39 minutes ago, manisandher said:

 

Absolutely - he has the digital stream captured in real time during the A/B/X. He's probably analysing it right now :-)

 

Mani.

 Mani

 The results of the digital stream analysis, provided that the checksums were identical, will show no differences.

Alex

[sandyk]

1 minute ago, manisandher said:

Hi Alex, apologies we didn't get around to using any of the files you sent to me a while ago. We were a bit 'done in' by the end of the A/B/X.

 

 

I don't think talking about 'checksums' is appropriate here. We didn't use two different files that had identical checksums, but rather a single file played back in (what I believe to be, but to be verified by Mans) two different bit-identical ways.

 

(I see Mans got there before me.)

 

Mani.

Mani

 All that I am saying here is that Mansr will be wasting his time attempting further analysis of these files after he satisfies himself that they are identical.

As you both got along so well , perhaps you should organise a further session with Mansr under more relaxed conditions ?

You always seem to run out of time with these kinds of things, where you also need to have some relaxation time with refreshments.

Alex

[sandyk]

3 minutes ago, mansr said:

There are also analogue captures.

 Now that sounds interesting. What equipment did you use to do this ? 

I sometimes wish that I still had my original Nakamichi tape deck.

[sandyk]

1 hour ago, manisandher said:

All I know is that the two settings give bit-identical replay... but sound different.

 Which is what I have been insisting for many years. How they were generated is beside the point. It doesn't matter whether the perceived audible differences were generated by Software manipulation or Hardware changes.

Mani, Peter, and others have previously verified in this forum that the latter is also possible.

 

Dennis

 How do you propose to make available the Analogue captures without first converting them to digital again, where it is almost 100% certain that there will no longer be any audible differences ?

Alex

[sandyk]

9 minutes ago, esldude said:

I assume he used his Tascam to send the analog signal thru the ADC.  I didn't take it to mean he captured using an analog process like reel tape. 

 

Dennis

As I have previously stated on many occasions, any further processing, including a further A/D conversion will almost certainly result in no differences being heard, although recording at MUCH higher bit rates and depths MAY help ???

What we need at this time, is more relaxed collaboration between Mani and Mansr, and we will likely learn much more.

 Mani has perhaps among the best proven hearing abilities in this forum, as evidenced by the " glitch" episode ,that was due to being heard, NOT seen, and Mansr has perhaps among the best overall technical abilities of the majority of the E.E.s that are regular posters ?

 

Alex

[sandyk]

1 minute ago, esldude said:

The PLOT thickens!!!!!

Yes, unfortunately.

 Undoubtedly Mani will confer with Peter on this issue, and hopefully , the collaboration between Mani and Mansr will continue. 

[sandyk]

14 minutes ago, manisandher said:

 

I realise this is anything but trivial, but have you managed verify that, discarding the first 45ms or so (due to the recorder's 'auto-record' function), all the captures taken during the A/B/X are indeed bit-identical?

 

Mani.

 

 A very good point ! This MAY also apply to the end of the track ?

[sandyk]

3 minutes ago, mansr said:

Skipping the first 10k samples, they are all identical.

 

That's good news, as you now definitely have something worthy of further investigation.

 Well done, both of you !

[sandyk]

3 hours ago, manisandher said:

But I have to say that I think doing an A/B/X is absolutely horrible. For me, it's like focusing on going to sleep - the more you do it, the further you get from your objective.

 

 It may be fine for those without a vested interest in the results, but it's a different matter when it's your credibility at issue.

 It's then not the normal way that you listen to , and enjoy music.  It can be quite stressful as Mani has found too.

.

[sandyk]

15 minutes ago, phosphorein said:

....Understanding the exact mechanism at play in this instance is of interest more generally too, because it'll be the same mechanism that causes playback from two different locations to potentially sound different - (Mani as quoted by Phosphorein)

 

 In some cases, even when the files saved at 2 different storage locations are completely saved to System Memory before playing them with a suitable S/W player !

[sandyk]

17 minutes ago, STC said:

Mani already said that the files captured from the digital output sounded the same so we can conclude bit-identical files do sound the same. 

 

 Garbage !

 They may have sounded the same after being captured and saved to HDD/SSD again,(additional processing) but that does NOT mean that they did when they were played originally.

You are reading into this what you believe the results SHOULD have been according to your present limited knowledge of the subject.

ManI also had available to him other comparison files that had been saved to the same device, that he could have also used, but he simply ran out of time.

 

 

[sandyk]

4 hours ago, pkane2001 said:

 

I think the test was legit, it just didn't test sufficiently for what was the original premise: audible differences between playback from NAS and from local storage.

 

 Mani was able to do considerably more and had other methods available that  he could have used , including some comparison .wav files that I sent him, but they simply ran out of time, otherwise the 9 out of 10 sequence could have been increased as well. 18 out of 20 for example would certainly have convinced more members ?

It takes a lot of time to set up and do these things, as has been shown here at the various listening sessions I have been invited to attend and participate in. You also need to take at least one refreshment break to refresh your concentration.

[sandyk]

1 hour ago, phosphorein said:

To my mind, the only mechanism that could be causing different jitter signatures are different noise profiles generated in the audio PC, somehow finding their way to the DAC.

 

 It has been reported by an E.E. some time back that certain types of Jitter can  result in low level Wideband noise.

[sandyk]

 Mani

 I suspect that you may need an ADC with 32bit resolution at a high bit rate such as 384 to capture these tiny , but still audible differences.

Like Peter though, I wouldn't bet on being able to do so though.

 

 Perhaps another case of human hearing being more sensitive than previously given credit for ?

Nice work on  hearing those other Glitches though, that were later confirmed by measurements !

Alex

[sandyk]

Just now, manisandher said:

 

Alex, the DAC used for the A/B/X has an old 16-bit 1543 chip. I can't see how 32/384 is going to help, over the 23/176.4 we used to capture the DAC's analogue output.

 

Mani.

 

 I think your really need at least a 24 bit ADC. A 16 bit DAC may still output some ultrasonic rubbish, perhaps as a result of RF/EMI break through ?

[sandyk]

3 minutes ago, manisandher said:

 

That was a typo (now corrected). The ADC was 24 bit.

 

Mani.

Incidentally, FWIW,  BarryD. remarked about my worse sounding comparison files "... as though some random treble energy surrounded the details in the recordings."

Perhaps due to PSU noise , Jitter ?

 

[sandyk]

7 minutes ago, manisandher said:

 

Hopefully this will help:

 

 

Mani.

Mani

 Did your Audio PC have 2 separate Coax SPDIF outputs ? If not , could using a splitter have resulted in some audible degradation due to reduced input level to the DAC , perhaps making the comparisons  a little harder  ?

 

Alex

[sandyk]

8 minutes ago, manisandher said:

* You could try listening to them as well, but I have to say that they all sound the same to me.

 Mani

 Your hearing is way  better than mine, but I would be interested to see if I can hear any difference between a single sample of each as .wav files, perhaps uploaded as Zips ?

 

O.K. on the dual BNC outputs .

 

Alex

[sandyk]

11 minutes ago, manisandher said:

 

Will do Alex... but I'd rather wait until after Mans has reported back with his analysis. Hope that's OK.

 

Mani.

 Of course.A Digital capture would be preferable though, to see if I can hear what you heard.

Anyone taking bets on the result ?