DAC audible differences are finally proven with ABX?

[SSS]

The heck you talking about? Legal rights?

You think you all have legal rights to ask me to measure his box and that is why I would be doing it? And not as any type of search for truth and understanding about this test?

I am putting my funding and time toward this work. He on the other hand, wants to take advantage of the situation by extracting tons more money because he thinks he has cornered us.

It is all about ethics and doing what is right. I owe to you all my time and financial resources to up level our understanding of audio. Josh on the other hand, seems to be after making a buck. Don't go defending this kind of conduct. He should have provided you with the files at the start and arranged to loan me his box to measure. Period.

I did not ask you to test the box. For me the whole discussion goes to nirvana. Forget Josh and his test. Forget the box. If various DACs may sound different, create an own test. And anyway there are lots of questionable tests on the internet and youtube.

 

[Thomas_A]

With headphones I can hear a very small change in the lower tones. But when looked to the waveforms in Audacity then the second part had not really the inverted sawtooth. Therefore it is not a valid test file for polarity inversion.

View attachment 549570

Ok. Thanks, something wrong with the file then. I will post two correct files for ABX instead tonight. These files are more ear-friendly.

 

[pma]

With headphones I can hear a very small change in the lower tones. But when looked to the waveforms in Audacity then the second part had not really the inverted sawtooth. Therefore it is not a valid test file for polarity inversion.

I will check it with AA and DW.

 

[Thomas_A]

There was a post earlier in this thread with a screenshot of the Matrix XSP review. The MQA version just adds MQA support and a newer USB chip (XU216). But I also posted the impulse response from my XSP MQA’s RCA output.

Thanks for that. I bought the Matrix XSP review in Hifi News, which do not state the output of the unit tested. It also is not the same unit (MQA) and Matrix have added op-amps to the output stage in the Sabre 3. So a check is warranted. Other than that the R30 shows a different filter from the impulse.

But its settled then.

 

[pma]

With headphones I can hear a very small change in the lower tones. But when looked to the waveforms in Audacity then the second part had not really the inverted sawtooth. Therefore it is not a valid test file for polarity inversion.

Yes, the file posted by @Thomas_A has been wrong (it is always good to double-check before posting data).


I think that the author wanted to make this:


Below I am attaching the correct file:

 

[RandomEar]

That explains it. Amazes me that no one asked him why he was being so greedy and how that was good for advancing the research.

To be clear: I think he was (mostly) joking in that post. Nonetheless, based on his previous posts in this thread my impression was that he invested a lot of effort into getting it and absolutely didn't want to part with the comparator. I was quite surprised that he offered it to you via PM.

The newest posts from today support that impression. Asking twice what he paid in total - and thereby around twice the actual market value - for the device seems to be pushing it. Doesn't matter whether 50% of that goes to a charity, somebody would still have to lay out the money. Josh would clearly prefer to keep the comparator, which, in the end, is his choice to make.

Also sad to see that this thread has gotten pretty ugly with some of the latest posts.

 

[SSS]

Ok. Thanks, something wrong with the file then. I will post two correct files for ABX instead tonight. These files are more ear-friendly.

Viewed the analog wav with an oscilloscope did not show really a sawtooth signal. Played with Foobar and Win-11 PC internal ESS DAC chip. Maybe this setup is not able to clearly reproduce a sawtooth signal? Perhaps an inspection at the digital side with proper tools may show it better? Does anyone have an idea of such a software tool which shows the waveform like an oscillsope?

NEW: I have to apologize that the waveforms were much distorted by my PC replay setup which in some way modified either the digital or analog signal. A different setup with external DAC USB box and ASIO driver the signals were OK as expected. See posts below.

First part of the wav file and below it the second part:

 

[voodooless]

Does anyone have an idea of such a software tool which shows the waveform like an oscillsope?

REW can do that

You should see what your multi-way speaker does to these kinds of signals if you capture if from a microphone

 

[pma]

Viewed the analog wav with an oscilloscope did not show really a sawtooth signal. Played with Foobar and Win-11 PC internal ESS DAC chip. Maybe this setup is not able to clearly reproduce a sawtooth signal? Perhaps an inspection at the digital side with proper tools may show it better? Does anyone have an idea of such a software tool which shows the waveform like an oscillsope

1) the file posted by @Thomas_A is wrong in part 2. Use mine posted in #946. Analyze data.
2) you have to many variables in your setup. Avoid WDM, use ASIO driver and proper sampling frequency to avoid sampling frequency conversion. Do you want for me to make an oscilloscope shot? These self-tests are prone to dozens of user failures.

 

[SSS]

Yes, the file posted by @Thomas_A has been wrong (it is always good to double-check before posting data).
View attachment 549588

I think that the author wanted to make this:
View attachment 549589

Below I am attaching the correct file:

Thank you for the file. With my setup the waveform looks as weird as the former one. Maybe really my PC DAC chip circuit?

 

[pma]

Thank you for the file. With my setup the waveform looks as weird as the former one. Maybe really my PC DAC chip circuit?

My post #950.

 

[SSS]

1) the file posted by @Thomas_A is wrong in part 2. Use mine posted in #946. Analyze data.
2) you have to many variables in your setup. Avoid WDM, use ASIO driver and proper sampling frequency to avoid sampling frequency conversion. Do you want for me to make an oscilloscope shot? These self-tests are prone to dozens of user failures.

IF possible, yes. Interested in an oscilloscope picture. And what is the replay chain to feed the scope?
My user errors may be not to know or use the right software tools and the uncertainty what my PC DAC does?
On the analog side I am an experienced technician.

 

[pma]

IF possible, yes. Interested in an oscilloscope picture. And what is the replay chain to feed the scope?
My user errors may be not to know or use the right software tools and the uncertainty what my PC DAC does?
On the analog side I am an experienced technician.

Here we go, from my file that I posted few posts above, AA, ASIO, Focusrite 2i2 headphone out. Y-axis is calibrated for 10x probe, so the Y axis voltage division is in fact 0.2V/div, as it was measured without a probe, directly.



It is also a pain of user performed listening tests that the condition and setup of their systems remains unknown, so the sighted impressions may be very unreliable. That’s why we need controlled tests.

 

[SSS]

Here we go, from my file that I posted few posts above, AA, ASIO, Focusrite 2i2 headphone out. Y-axis is calibrated for 10x probe, so the Y axis voltage division is in fact 0.2V/div, as it was measured without a probe, directly.

View attachment 549602 View attachment 549601

It is also a pain of user performed listening tests that the condition and setup of their systems remains unknown, so the sighted impressions may be very unreliable. That’s why we need controlled tests.

Thank you. Seems that my setup needs to be evaluated. Will try an external USB DAC. At REW I did not find a way to display the imported file on the scope. Have you please a hint?

 

[pma]

Thank you. Seems that my setup needs to be evaluated. Will try an external USB DAC. At REW I did not find a way to display the imported file on the scope. Have you please a hint?

No. It only works during real-time analysis.

But Audacity should work to display roughly time domain shape of the signal wav file. - Confirmed, it works.

 

[pma]

At REW I did not find a way to display the imported file on the scope. Have you please a hint?

As I mentioned, it works in RTA (real time analysis) and then the scope works. Below a sawtooth sent via Bluetooth from MacBook to BerryBak amp and analyzed in frequency and time domain by REW. Works well. REW sawtooth generator used. LF corner of the amp is visible from the ramp being not a perfect straight line.

 

[danadam]

I was never able to get correct spectra from Audacity by increasing FFT size. The result was a loss of amplitude at higher frequency components. If you are able to set Audacity to get the spectrum results as I have shown in post #899 (above yours), I will be glad to learn something. All the analyzed files are available on links that I had posted.

Audacity is very bad at rendering the plot from the calculated data. Making the window wide may improve things a little:

Why so strange plots in Audacity

This is a common stepped sine sweep from Ultimate Analog test record form Analog productions, track A6, recorded with RIAA active Why does the plot look normal in CoolEditPro2=Adobe audition but ro ragged and sloped in Audacity-Right side. What am I doing wrong, many people use Audacity but I...

www.audiosciencereview.com

But the underlying data seems correct. If you export it and plot externally you get:

 

[pma]

My user errors may be not to know or use the right software tools and the uncertainty what my PC DAC does?

Is it Windows or Mac? If it is Windows, do you use ASIO, Wasapi, or intrinsic Windows WDM drivers? Is the EQ disabled? Sample rate conversion or not? You may check all this in the Control panel.

 

[voodooless]

Audacity is very bad

You could have stopped there. Best to just avoid Audacity altogether.

 

[SSS]

No. It only works during real-time analysis.

But Audacity should work to display roughly time domain shape of the signal wav file. - Confirmed, it works.

Wow, not it works OK. Attached my Creative E-MU Tracker with USB and ASIO driver played the file with JRiver (test period). Now I get the real sawtooth on my external oscilloscope. Pics attached here: