Quality test of AD-DA

[Diddledoe]

I recently bought an A-16 Ultra (Creamware) to substitute my ProTools LE. Just to use these new in-outs with other windows programs I took a hammerfall card too. Then I wondered what the quality of ad-da conversion compared to the digi001 might be.

Therefore I thought about a test setup:

I generated a pink-noise signal lasting for 60 seconds and overlaid it with one very steep and narrow signal at 10k as a sourcefile.
Run through a spectrumanalyzer this signal looks like single ruler like line from 5-20kHz with one very steep peak at 10k.

This signal was routed from Digi001 1-2 out to 1 and 2 in and recorded. Next I did a similar routing with the same sourcefile on the A-16 Ultra. Afterwards I analyzed all recorded signals and compared them with the generated one.

The results were quite interesting and astonishing. The resultfiles recorded on the digi001 differed heavily from the sourcefile. The the ones recorded on the A-16 were more or less identical to the sourcefile except that the power of the signal was on all bands higher (but still linear more power).

So, what do you think of this test?
Could this be a good setup for testing ad-da conversion?

[minimoog]

numbers are numbers.

what sounds ok is more important.

if you did an a/b test between a source signal recorded on analogue tape and some digital format or other, i'm sure youd find the results far more interesting than a converter comparison.

instrument accuracy wise, the digital format will almost always win but using full programme material and your ears, i'd be surprised if you picked the digital recording over the analogue.

i mean at the end of the day, they're all converters, and there in lies the problem...

[Diddledoe]

True, but somehow I would like to compare things. And all in all it it good to know your hardware just to compasate during the mix.

By the way, if you want to take a look at the results I just setup a VERY simple webpage at:

[removed]

[Jayman#9]

I thought that was an interesting test. I know that the converters on the Digi001 aren't the best just by listening to them, but to know technically what's going on is also a good piece of knowledge. Good job.

[Diddledoe]

Just to inform you, I've redone the same test with all the other ports of the digi001.

The all surprising result is:
During my first test there must have been a sync problem (jitter??), because the results are now totally different and much better for the digi001. It appears to me now that both digi001 and A16-Ultra are more or less on the same level.

Hmm, I have to think about this...

[Diddledoe]

By the way, because of misleading results I have removed the webpage...

[marcusb]

Originally posted by Diddledoe:
True, but somehow I would like to compare things. And all in all it it good to know your hardware just to compasate during the mix.

<font size="2" face="Verdana, Arial">Crikey, now i've heard everything. Compensating for the 'convertors' in a mix - ridiculous. I think you are thinking WAYYYY too much about the numbers and not enough about the music. Maybe do a lot more mixing, get more experience and your mixes will improve. Looking at a poofteenth of a db here and there on flawed test is looking for problems where none exist. Are you looking for numbers to justify your purchase because you can't hear a difference ? If your computer is in the same room that you monitor in you aren't gonna hear differences in convertors anyway.

I'd test using my ears (heck that's what all my judgements and choices are based on).

Cheers,
Marcus