Blue or red pill?

[Sonicularity]

There is clearly a tell that is identifiable, and hopefully the additional analysis will reveal the source.   The initial test results indicate that there is no preference between the two samples, only a means to identify one from the other.

[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

[mansr]

The digital captures are not identical.

[fas42]

Whooops ...

[esldude]

6 minutes ago, mansr said:

The digital captures are not identical.

The PLOT thickens!!!!!

[esldude]

12 minutes ago, sandyk said:

 

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

We apparently needed one more minute as mansr's post was a minute after yours.  So  or  or 

[pkane2001]

16 minutes ago, mansr said:

The digital captures are not identical.

 

I know it's early in the process, but could you and/or Mani, at some point, document what equipment  and software was actually used for playback and recording, and how everything was inter-connected? Software settings, file formats (source and recording), protocol conversions, etc. would all be useful to describe. This may aid in understanding, but also if anyone may want to reproduce the test in the future.

[manisandher]

15 minutes ago, mansr said:

The digital captures are not identical.

 

You have 14 digital captures with SFS=0.1 - are these bit-identical?

You have 16 digital captures with SFS=200 - are these bit-identical?

 

At what level are the SFS=0.1 digital captures different to the SFS=200 digital captures?

 

Mani.

[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. 

[mansr]

20 minutes ago, mansr said:

The digital captures are not identical.

The differences are only in the first ~8000 samples of each capture. Some captures are identical.

[manisandher]

1 minute ago, mansr said:

The differences are only in the first ~8000 samples of each capture.

 

Ah, OK.

 

I've come across the Tascam doing something really strange when set to 'auto-record' (as we had it). At one point, it seemed to flip the channels for the first second or so.

 

I think the files can still be used to verify that playback was bit-identical, if you just discard the first ~8000 samples.

 

Mani.

[esldude]

3 minutes ago, mansr said:

The differences are only in the first ~8000 samples of each capture.

So at 176 khz rates about 45 milliseconds.  Are those 8000 of the same part of the waveform, but differ or is something else going on?  Sorry for the impatience.  Never mind my question, you'll give us a good analysis in time. 

[manisandher]

9 minutes ago, mansr said:

The differences are only in the first ~8000 samples of each capture. Some captures are identical.

 

The two 10kHz digital captures should be bit-identical because we didn't use the 'auto-record' function on the Tascam.

 

Mani.

[mansr]

6 minutes ago, esldude said:

So at 176 khz rates about 45 milliseconds.  Are those 8000 of the same part of the waveform, but differ or is something else going on?  Sorry for the impatience.  Never mind my question, you'll give us a good analysis in time. 

Here you can see the difference:

[manisandher]

15 minutes ago, pkane2001 said:

 

I know it's early in the process, but could you and/or Mani, at some point, document what equipment  and software was actually used for playback and recording, and how everything was inter-connected? Software settings, file formats (source and recording), protocol conversions, etc. would all be useful to describe. This may aid in understanding, but also if anyone may want to reproduce the test in the future.

 

I'll certainly do this.. but it'll have to wait until tomorrow now.

 

Mani.

[Superdad]

Just now, manisandher said:

The two 10kHz digital captures should be bit-identical because we didn't use the 'auto-record' function on the Tascam.

 

10kHz digital captures?  I though you used music tracks.  Please explain.

[mansr]

Just now, Superdad said:

10kHz digital captures?  I though you used music tracks.  Please explain.

We did both.

[manisandher]

Just now, Superdad said:

 

10kHz digital captures?  I though you used music tracks.  Please explain.

 

We took some additional captures of 'test tones' after the A/B/X with a music track.

 

Mani.

[esldude]

2 minutes ago, mansr said:

Here you can see the difference:

That looks like the one set of samples are all a slightly higher value the first 8000 samples.  If you export the bit values and look is it some consistent difference between each sample between the two files?  

[pkane2001]

6 minutes ago, mansr said:

Here you can see the difference:

 

This looks like a small difference and of similar magnitude. Is it just in the LSB? Perhaps dither causing this?

[manisandher]

The first ~8000 samples need to be totally ignored, when we used 'auto-record'. It's the Tascam at fault.

 

Mani.

[esldude]

8 minutes ago, manisandher said:

The first ~8000 samples need to be totally ignored, when we used 'auto-record'. It's the Tascam at fault.

 

Mani.

Can you setup the Tascam to record something played twice and show it messes up the first 8000 samples one way vs another?  That would be something. 

[manisandher]

We can only conclude that playback was not bit-identical if:

 

1. the 14 digital captures denoted '1' (with SFS=0.1 in XXHighEnd) are all bit-identical to each other

2. the 16 digital captures denoted '2' (with SFS=200 in XXHighEnd) are all bit-identical to each other

3. the digital captures denoted '1' are consistently different to those denoted '2'.

 

I very much doubt that this will be the case.

 

Mani.

[manisandher]

5 minutes ago, esldude said:

Can you setup the Tascam to record something played twice and show it messes up the first 8000 samples one way vs another?  That would be something. 

 

Not twice, but 14x in one case and 16x in another!

 

As for testing whether the 'auto-record' is at fault, it should be obvious by comparing the captures after ~8000 samples - as you said, a tiny fraction of the total file.

 

Mani.

[mansr]

The 10 kHz digital captures differ all the way through.