No it's not that. I'd sell a piece of gear in a heartbeat. I'm not dedicated to any brand. I'm just hearing a big difference in my Rosetta 800 recording the same Fantom Demo and your Rosetta 200 so it makes me think there must be a big diff in the units that are supposed to differ only in the number of channels (Or there's a flaw here somewhere)heh

Please define source and accurate!

We have a reference track (which I haven't heard :-) and we have some combination of AD and DA in the three tracks. Any alternation on the three tracks from the reference is coloration from the contenders AD since the Fantom DA and your own DA is the same for all tracks.

Can't be so hard to uderstand that IMO.

Earlier you wrote this;
Which makes no sense at all.

You don't need Paco De Lucia in Royal Albert hall to create a track for testing coloration of audio gear, and you don't need to know what it sounded like there during the performance. You need "before" and "after". A ref track that you can listen to and and the same track that has traveled thru the DUT. That's it!

It seems this is much about the Fantom DA and the questioning of it's quality but that reasoning doesn't make an awfull lot of sense since everybody has gear that colors the signal somewhere.

What one must realise though is that all audio testing and the results from them is specific for the particular set up, the specific material listened at, the listener, the room and so on. The results are never universal so to speak.

Let's assume that the signal was looped thru the converters without the Fantom DA... (which of course is interesting and makes sense as well) then we would have two unknown variables on every track/file. Now they share the same DA (the Fantom) only the AD in the contenders differes.
This make sa whole lot of more sense than some of the participants in this thread seem to realise.

The ideal situation for this test would be a known DA that was 100% transparent and also monitoring equipment that was 100% transparent.. and rooms that... you get the picture?



/Peter

no problem, as far as everybody talking about listening, this test is not entended for the DA monitoring side of the converters but only for the AD. you actually don't even need to listen, just by looking at the frequency snapshot you can tell which is closer

If it was looped the unknown variables would represent the converters and what they did to the sound. We could compare what the converter brand did to the original that was recorded digitally. It would have the sonic stamp of the converter brand on it. As it stands we are hearing what the converters are doing to the signal after it is converted by the fantom (And we have no idea of what the Fantom is doing. because there is no reference. If it were looped though you couldnt judge the A/D alone, you could use the digital track as a ref then.)

Yes but the converter still is (at least) two pieces of gear..an AD plus a DA. Obviously that makes sense if the material is going to be recorded and also enjoyed on the same machine but perhaps not otherwise. Now, it's not very likely that the errors in the two sections (AD and DA) would cancel.. so if a converter like these tested is transparent it's relatively likely that the AD and DA sections are transparent respectively. Exactly the same way as if the Fantom DA and "X" AD is used together.


No. It would have the sonic stamp of one AD section and one DA section. There's no such thing as "brand sonic stamp".. only bandwith, noise and distortion.

Do you know what the mic capsule did? The mic electronics? The micpre input stage? Voltage stage? Driver stage? Do you know what your DA, preamp or mixer do? Your power amp? Your passive or electronics x-overs? Your speaker drivers? Your cabinets? Your room.. ok I'll stop there. ;-)

Yes there is. The reference is the track that has not passed thru the Fantom DA and "X"-AD. You must let go of the idea that the DA needs to be in the same chassi as the AD.


But how do you get to know the DA in the same converter? The situation is the same. And this is what we have to deal with with devices that are not pure transmission links. You can not test (audibly) them in isolation. Same goes for speakers. Gear that has input and output in the same dimension is easier to put thru before/after tests, obviously.


/Peter

It's pointless to refute this nonsense.heh

What I meant by converter brand is that you would know what the Apogee's conversion does comparative to what the Aurora does etc....

If you think comparing a digital track as a reference to the output on a midi soundmodule D/A makes the digital track a ref, I don't know what to tell ya.

well again...a original NOT converted track (spdif digital into PT)
compare it with 3 final results. it doesn't matter how many DA it went thru!! yes the result will be different from the original but now which one is the closest?
If I went from the fantom DA to "x converter1" then to maybe another "x converter 2 "
repeated the same thing 3 times keeping "x converter1" but switching "xconverter 2" Yes I would get different results from the original BUT because the similarity of the chain has been respected (fantom DA and "x converter 1" was never changed, only "x converter 2" was) Then Ultimatly 1 STILL would be closer to the original then the others, How close ? Not sure but Closer then the 2 others yes

Dear Mickaël

I read your test and appreciate you are trying to do this. However as you noticed, doing a proper AB test is not as easy as it looks. This has to be done in a very controlled environment with preferably a few people observing every step you take.

There are a few flaws and unknowns in your test setup.
Let’s start with the source, the Fantom. For what I understand, this is an instrument (consumer) output level device. Which means, not enough to drive a converter expecting a professional level. As you mentioned the Rosetta 200 needed a lot more signal than you had available. So you fixed that by raising the level in Pro Tools, correct?
With that setup, you basically run the AD converter at a much lower bit depth than it potentially can. With a 16 bit source of the fantom you are now running an even lower number of bits on the AD converter because you are not getting to full scale. Raising the level afterwards in the digital domain (in PT) does not enhance the bit depth (resolution), it just makes it louder. Including all the artifacts (like distortion) of lower word length conversion.

You are apparently not aware of the feature to adjust the input level (and output) of the Rosetta 200. That way you would have a more optimal conversion. Please read the manual for the correct procedure

I assume the output of the Fantom is unbalanced. If so, make sure the unused pin (usually pin 3) of the XLR input is tied to ground. If not the transformer behavior like input of the Rosetta 200 will result in a loss of low frequency response and an overall “muddiness” in the lower mid range (as you noted)

Make sure the soft limit is off. (Very often a forgotten function)

It would be better to use the digital output of the Fantom with a high quality DAC for your conversion. The built in DAC’s in electronic instruments are usually not that great.

Far better would it be to use a natural source, like they recently did at the Fox stages to evaluate the best converter for their orchestral recordings. Blind listening tests were done comparing the converted version to the source (a life string quartet). I guess I don’t have to tell you who won that contest…

The bottom line is indeed comparing to the source ( I do that all the time with every new design). What does it do with your image, your spatial information, your depth? If there is a huge tonal difference like you describe, there is usually something wrong with the setup.

As Dr. Joy Degruy Leary noted, he did not hear the differences you noted with his Rosetta 800. They are indeed very much alike with the exception of the option to adjust the gain of the 200

Best regards,

Sorry but we have to do this a bit more! heh

Ok, a reference is something that you start from.. a standard for a measure in this case. A rererence is not a nice box that costs a lot of money. You can use ANY sound as a reference. Something that is way more important than which DA is used is what kind of material is used. To get a grip on a DUT you may need to provoke it with signals that push its weaknessess (sorry for spelling on that one). Now I have to confess I don't really know what material is on these three files. There was some talk about voice and guitar, right or wrong? The test method does make a whole lot of sense IF it is the AD section that is under investigation.

But you still wouldn't know how much the AD respectively the DA in each converter/brand/box/module yada yada stands for an eventual coloration.

Now all three AD converters has the same DA in the loop... which makes this type of test more clever than the one that you propose.

It's all about what you want to find out about the gear. Now it was the AD that mdjice wanted to investigate.


/Peter

Hi, No the lower volume was on the AURORA NOT on the Apogee. The soft limiter was NOT on ( I just got the Lynx Not the rosetta and I did read the user manual when I got the unit)
Also The connections (cables) used was correctly setup and was the same for the 3 units anyways.
The excuses you gave for the rosetta (since it was recorded lower (but wasn't)) are actually for the Aurora which despite elements that you seam to say would have made the rosetta get lower results Got better matching results anyways.
I'm not trying to bash on any piece of equipment, just making my own test and sharing what I found. Is this test the best and most relevant? of course not but it does show well how with my type of work habits (pluging a Sound module to a converter then PT for example) the results would differ from one unit to another
M.

My words are not excuses, they just show deficiencies in your test. Whether in our favor or not.

Not every input circuit responds the same to a floating pin. So your cabling may work with one device, but fail with another. It sounds like you never dealt with transformer inputs; floating a pin has a major effect on the frequency response. Most of our gear emulates transformer inputs. So it is a good advice to check your cabling.

Hi!

Is a test like this called AB test? In my neck of the woods an AB test is when you compare two pieces of gear against eachother. In this test the idea (if I get it right, not very common these days..) was to listen to the signal before and after it has passed the device. I'd like to call it bypass test or before/after test.

The signal from the Fantom is analog and talking about lower number of bits on th AD there doesn't makes sense. That's like saying the AD runs at 12 bit when using a typical condenser mic becasue of it's noise.. that typically is higher than the 16bit digital audio noise. What's interesting is the analog level.


Balanced it seems.



In what way would that be essential to this test would you say?

Please tell some more about that test.


/Peter

Well my cabling is Brand new Mogami Gold and works for the 2 other devices so why not for the rosetta?..hummm do they make special cables that will work for my rosetta? I was not aware that some kind of cables (generic pro AUDIO CABLES) could NOT work on some devices.
A far as a Live feed if a performance is played twice, once thru each converter, the output WILL be different musicians will never play 2 takes the same way and it would then false the results (if recorded takes were always similar I would duplicate my vocal tracks 10times instead of stacking them!)

Hay Lucas when are you guys coming with an 8 or 4 channel of the X series convertors. Knock them out already man!!!!

Hay Lucas when are you guys coming with an 8 or 4 channel of the X series convertors with spidf. Knock them out already man!!!!

Fantom racks are unbalanced devices I wouldnt suggest you get in the practice of patching your module directly to a converter. I'd suggest a DI/Pre before it in your normal tracking situations.

I am
Please clarify ..

Original Source
2.wav is 1 - MAudio ? is it ?
3.wav is 2 - Rosetta 200 is it ?
4.wav is 3 - Lynx Aurora 16 is it ?


I have Lynx Aurora 16 , Rosettas (200/800) + BigBen , Myteks (192 and 8x96) and others converters
I have Maudio (1814 , Fast Track , Delta) ...
in YOUR "blind test" the Rosetta sound "dark" for my ears ! ?

I agree that Lynx is transparent , and Rosetta is "collor" ...

I dont know what to say ,
something "strange"

check the AURORA manual You can plug Balance or Unbalanced straight in the Input and the impedance will switch automaticly. No Need for a DI Box and that's straight from the Guys at Lynx (called them about that first thing when I got the unit)

YES

I checked your Openlabs page. I see you worked with serve. (He's a friend of mine We go back a good ways.)thumbsup

Lol yeah Serv use to be in my studio like everyday a few years back. I'v been touring non stop tough so when I'm in the studio it's more to work on major labels stuff. I have like a n entire album of him that I produced, never released cool dude. Very Street Smart

Its very simple. Source= the track which has already been prerecorded and mixed. It already exists and nothing will change the way it sounds. Accurate= means how well each converters preserves the original mix. We can hear the source and then determine how accurate it is. With the acoustic guitar and voice, we don't know what it sounds like coming straight out of your pres, thus there is no source.

To the op, sorry. I guess you can't do anything nice for people without them criticizing you and telling you how you could do it better.

Anyway, I like the Aurora better. Ha!

Often it's not that simple with comunication since it's common with loose definitions and "home made vocabulary". Often a basis for misunderstandings. Which this very thread shows clearly.

Okay. But a source could also be a source of sound, as in the acoustic event itself. A tapemachine or a CD player is often called a source. And finally as in this discussion it could mean the source material.. like the pre recorded track.


Or maybe how well the converters preserve a signal going into or passing thru.. There are recordings that are not mixed at all.

Call it source or refrence track or whatever. What you say still makes no sense at all. What is it that makes the point after the pre the magic point to tap a "source"? In such case your definition of accurate falls since that's no mix. Again, you don't have to know how the original acoustic event sounded.. or how the tapped pre signal sounded. You can have a mix that has been in and out of a DAW with effects and what not on it and still use it as test material and use as a reference track testing aduiogear.


/Peter

There is one situation though that I would accept the Fantom as being an inferior device (without measuring or testing carefully) and that would be if all three tracks would sound the same.

In such case it could indicate that the errors in the Fantom is of such magnitude that it masks the errors in the AD's in the converters. Now that is not the situation we have.. the test material (source or rather reference track and whatever the Fantom DO to the signal) is of high enough "quality" to show differences in the contenders.

Mission accomplished!

mdjice

Isn't the output from the Fantom balanced? The manual said 1/4" TRS?


/Peter

He's using a Fantom RACK don't read the Fantom keyboard manual they are different. The rack I'm almost sure is UNBAL (Yes they are different)

Glad you appreciate the effort put into this test. Again I'm in NO WAY making an official TEST where I scientifically compare the units but more a test for my everyday uses and that's all that matters for me. I could care less of the results form each units past 96Khz for example as I never use it.
The TRS out are Unbalanced

No, it doesn't really matter how transparent the Fantom's D/A converters are. It's not about errors. What matters is that we can't hear them. We can't hear the same signal that the three A/D converters here, so we don't know how accurate they are. Just because two of them sound closer to one another doesn't mean that they're more accurate. The D/A we monitor through has nothing to do with it since, as you mentioned, we are listening to all three signals through it. However we are not listening to samples from the same setup for each one. For the three samples with converters we are listening to the signal through the Fantom's D/A converters, into the A/D converter being tested, and then through our D/A converter. For the "reference" sample we are listening to the signal though our D/A converter, nothing else. For the test to be valid we'd have to be able to hear the reference sample through the D/A converter, which is impossible without going there (or at least without having a Fantom XR at our disposal).

You can't know that. What you need to compare to is the signal after it's passed through the Fantom's converters, not before.

What we're concerned with here is the fourth track, which is the so-called "reference" track. We need to know how the other three tracks compare to the sound coming out of the Fantom's D/A converters. The reference track tells us nothing about that.

No, it is not about the Fantom's D/A or its quality...it's about us not being able to hear the Fantom's D/A.

Then why listen at all?

And still, you can't tell which is closer, because we don't have a "frequency snapshot" of the signal coming right off of the Fantom's outputs.

True. But for it to be a valid test we need to be able to hear that reference, and we can't.

It's not about the quality of a cable, it's how a balanced input "sees" an unbalanced signal. Some are fine if you simply present them with an unbalanced signal, and some are not. This is another thing that needs to be known for a test like this to be performed properly.

Saying "nothing will change the way it sounds" is wrong. Any D/A converter you run that signal through will change the way the source sounds.

You said "we can hear the source"...but we can't. The source is the sound coming out of the Fantom's D/A converters.

As for the acoustic guitar and voice, you are correct. But the same holds true for the Fantom, since we don't know what it sounds like coming straight out of the Fantom's analog outputs. In either case, to do this type of test properly, you have to be there.

If you guys would like me to, I can post the same demo recorded on my Rosetta 800 into protools.

Lucas from Apogee nicely emailed me and we should arrange for a few apogee conv. to be sent my way to create new tests. He will also Help to make sure the tests are executed as fairly as possible (make sure I do everything right.
Don't know when yet as he mentioned he is pretty busy and I will have to go to Europe for 2 .
I will keep u guys updated and post any news.
M.

i've only been here 2 years but in all that time i've never seen apogee claim anything of the sort. i've never even seen an apogee owner claim anything of the sort.

come to think of it, i've never seen a post from apogee at all.


gregoire
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