Originally Posted by Waltz Mastering ➡️

Any clipping would only expand the test so that you can hear how that particular AD sounds when it is clipped.

Originally Posted by 24-96 Mastering

There's always a difference of one D/A conversion between the original and sources to compare to, whatever the test setup is. That's unfortunate but inevitable and no one has ever chosen converters in any other way.

Originally Posted by funka ➡️

That's why we tried to make A/D tests with an analog source, tape.

Originally Posted by 24-96 Mastering ➡️

An analog setup doesn't solve the principal problem that there's one more stage of D/A in the test signals compared to the original source. You can't listen to an A/D without D/Aing it first. Whether your source is analog or digital, that problem remains the same.

In the absence of an ideal D/A converter, it seems the only way to take the variable out of the mix to some extent is to repeat the test using different D/A converters.

Originally Posted by soundgeezer ➡️

I just tried something crazy:

I put the free plug attacker from spl on the master bus and while listening
to a small looped part of the original file I raised the attack knob till the red overload light was blinking.

Then I checked the other files to see what happened.
The loop was like 3 seconds long and on 1 kickdrum the over light turned red
when listening to the original track.
The only 2 other tracks, that made the over light turn red were the tracks
from converter 2 and 3 with the same setting of the plug.

Maybe all other converters don't translate the transient as well as #2 and #3 ?

It might be completely crazy to try this at home but check it out yourself and see what results and conclusion you might get.

Just my 2 ct as usual

Originally Posted by Boro ➡️

OK, let's set up an "ideal" set of input signals (at least two programs of different dynamic and corresponding spectral contents, each 2 minutes minimum) and define the test conditions! I mean:
- level to the ADC input;
- identical "filter" settings (phase-linear, steep, or whatever they offer identical!);
- NO manipulations of any kind over the input files! after the "agreement"!;
- perfect (as possible) power supply for every single unit;
- optimal interconnects, corresponding to manufacturers' requirements! NO optical connections, of course;
- double checked in-situ settings, i.e. test made at two (at least) different locations.

Please, add what you find appropriate to make it as objective as possible!

Originally Posted by Waltz Mastering ➡️

When will you be posting the files ; )

Originally Posted by Boro ➡️

I am not performing the test, just offering a fair conditions! Are you capable to make a really objective test happen? Do you have at hand that bunch of oh-so-expensive DAC/ADC converters?
Well, if someone has it all I'd be more than happy to help with the preparation for a serious and revealing test!

Originally Posted by inlinenl ➡️

who cares if it all was 100000000000,9999999999999999 % straight/clear test ...
just have fun, listen, make up your own mind, listen once more .. tickle your brain ...
life is there to enjoy ...

really enjoyed what robin did ...

Originally Posted by 24-96 Mastering ➡️

[size=3][b]

On the recording setup:

- All A/D converters were fed the digital source via the same D/A converter
- All A/D converters were clocked internally at 44.1 kHz
- All converters were at their neutral or default settings
- There was a bit of copper between the D/A and the A/D
- The files have been aligned and level matched to make objective comparison easier
- I took reasonable care in making those samples, but this is by no means a scientific test setup, so don't rely on this alone to make any important decisions.
- Since the differences are reasonably small, it may be useful to make a loop and listen to a short repeating segment to factor out changes in the music over time. Others advocate long term listening to get to conclusions. Whatever works! If you want to completely rule out placebo, use ABX or another blind testing method to confirm your findings.


The converters sampled are (listed in random order):

Prism Orpheus
Crane Song HEDD192
Mytek 8x192
Universal Audio 2192
Lavry Gold
Forssell Technologies MADA-2 (prototype)

A big thanks to MrVelvet for bringing 4 of the 6 converters along!



If you want to make sure your result is not biased by other people's observations, do the test before reading posts below or viewing poll results. They will (in all likelihood) influence your perception!

Originally Posted by mrlouie ➡️

ok im kinda slow but am i reading that the A/D 's are not level matched(set at some factory default) but then the files After going thru A/D were level matched ??? The A/D's should all be level matched within .01 then the files recorded shouldn't be touched at all (level ). If the A/D's themselves aren't level matched it doesn't seem to make sense if you really want to shootout each other, well atleast to me



louie

Originally Posted by 24-96 Mastering ➡️

We did adjust / looked after gain but most units were close enough in level to make us not want to open the bonnet on loaned test units.

And to be frank, I personally am convinced that a clipped tom at 1.11m doesn't change everything, and I don't believe that the character of a converter changes completely depending on whether you drive it 0,5 dB hotter or lower. If you think differently, then these files are not for you.

Originally Posted by Audiop ➡️

Robin,

it's not much to think about really since it's been prooven that gain changes as small as 0.1dB can be heard in some situations and therefore that's the minimum when matching sound files for serious testing. Often 0.05dB is used when level matching.

Small gains changed like 0.5dB can easily be heard on some material and you typically do not hear it like a difference in SPL but as differences in tonality and dynamics.

The test becomes even less useful if normalizing take place after clipping depending on how the software judge rms and peaks.

Changes are you are fooling yourself using these files to evaluate the character (or lack thereof) of the converters.


/Peter

Originally Posted by Boro ➡️

Not a fair test - simply because the files were manipulated (properly by the author of the test) to provide exactly the same RMS level, which doesn't mean exactly the same peak level doe to the distortion caused by clipping!
Just make your test only with the "Original" file and see what happens, then read THE WHOLE conversation here and you'll find out why!

Originally Posted by Audiop ➡️

Robin,

it's not much to think about really since it's been prooven that gain changes as small as 0.1dB can be heard in some situations and therefore that's the minimum when matching sound files for serious testing. Often 0.05dB is used when level matching.

Small gains changed like 0.5dB can easily be heard on some material and you typically do not hear it like a difference in SPL but as differences in tonality and dynamics.

The test becomes even less useful if normalizing take place after clipping depending on how the software judge rms and peaks.

Changes are you are fooling yourself using these files to evaluate the character (or lack thereof) of the converters.


/Peter

Originally Posted by mischa janisch ➡️

I honstly think it's time to give Robin a break. He clearly stated upfront that this was NOT a scientific test and explained how things were done in his first post - no surprises when someone decides to download and listen. AFAIK Robin did not force anyone to participate, and I believe after 100+ posts all possible flaws have been discussed in depth. I would think it is the right time to reveal the converters...

Originally Posted by soundgeezer ➡️

I guess we learned once again that the differences are subtle and I could work with any of those converters and concentrate on the music

Robin, you did a great job and it was a pleasure to listen to the subtle nuances of those high end devices, thanks very much ...

Originally Posted by 24-96 Mastering ➡️

???

Duh.

Are you guys not getting that the files are indeed level matched (to 0.0X dB by nulling test)? It's only that the fine tuning was done in the digital domain, not the analog.

Originally Posted by mischa janisch ➡️

I guess we're in some sort of loop mode - now someone has to ask again why you didn't match the levels...

Originally Posted by 24-96 Mastering ➡️

Indeed

I think it's about time to publish the results. Everyone wishing to listen to the samples before I do, go ahead now. I'll post which # is which converter model in a few hours.

Originally Posted by 24-96 Mastering ➡️

I'll post which # is which converter model in a few hours.