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  #11  
Old 08-22-2003, 01:53 AM
Rob Aubrey Rob Aubrey is offline
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Default Re: Apogee Rosetta 800 clocking

I
Please read and understand what I said in my post above. I am not saying that the Rosetta is no good at all, I have not even used it as an AD/DA yet as I have had no time to wire it in for that purpose yet. My post was referring to THIN ICE who I know personally and we have been discussing the way to go on both our PT systems. His question was relative to ROSETTA Clocking and that is what I replied to!

This is what I did to come to that CLOCKING conclusion.....now if somebody can tell me a way to improve the result I would be very willing to try it.

..............OK so I got the ROSETTA 800 about 4 hours ago and wanted to do some initial tests to see if the wordclock was any better than my YAMAHA 02R desk.......which many people had told me it would be a big improvement.

Once again please understand that these tests were only using the ROSETTA as w/c NOT as an AD DA as I have not had a chance to wire in the cables yet!

I recorded some white noise in MONO onto a track on the PT and then drew in a pan curve from CENTRE LEFT and RIGHT on the track and played it out via AES op of the desk direct to SADIE DAW editor.

I played out using the desks internal clock and then the desk clocked from the ROSETTA

I repeated the test with stereo audio track of music and with a full mix of about 40 channels (with no live keys or reverb as this will be deceptive when trying to assess the resultant ) each time clocking to internal then ROSETTA.

Then I imported all the tracks back into PT through TOAST AUDIO EXTRACTOR and lined up all the INTERNAL/EXTERNAL recordings by start frame and phase inverted one of the stereo pairs.

Most of you will know where I am going with this but if you do not then the law of physics /Maths or electrics whatever means that 2 identical recorded streams at the same volume with one phase inverted will cancel out totally.

What I wanted / and was expecting to hear was slight differences in each of the recordings especially the stereo program material as it has been stated here that a clock might provide a wider/more pronounced stereo image and more depth etc.

What did I hear as the result................ ABSOLUTELY nothing, no audio output heard at all on any of the passes.

Can I draw the conclusion that the ROSETTA clock is no better than the Yamaha THIS IS A QUESTION .... NOT A STATEMENT!!!!!!!(or the Yamaha is as good as the Rosetta if you prefer!) Or is there something that I am missing here? Like should I get the BIG BEN also.......£££££££££££££££££

ROB
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  #12  
Old 08-22-2003, 02:27 AM
thin ice thin ice is offline
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Default Re: Apogee Rosetta 800 clocking

Hi Rob,

I was hoping you would be able to conclusively hear a difference. If you could not detect an improvement with these tests, what hope would there be for your clients or for that matter the end listener? Maybe the audio was already compromised by the clocking during the recording process. I'm sure the converters will play a major part in improving your setup when you get it wired in. I'm still curious if anyone has an idea what the best clocking method will be using the 800 as the master clock.

Karl
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  #13  
Old 08-22-2003, 06:46 AM
digigirly digigirly is offline
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Default Re: Apogee Rosetta 800 clocking

I had the same initial idea for upgrading my convertors.
But after a bit of calculating , I deceided to take the step to HD, mixplus exchange .
Was cheaper than rosetta+ clock.
Now I still have money left for a better clock, and at the same time I'm up to date again with PT
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  #14  
Old 08-22-2003, 06:50 AM
Belushiman Belushiman is offline
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Default Re: Apogee Rosetta 800 clocking

Quote:
What did I hear as the result................ ABSOLUTELY nothing, no audio output heard at all on any of the passes.

Can I draw the conclusion that the ROSETTA clock is no better than the Yamaha
The utility of an ultra stable word clock only comes into play at the conversion to digital and the conversion back to analog.

While its in the digital domain its all just 1's and 0's and as long as nothing is broken and no processing is being done those numbers could bounce around a million times with a lousy clock source and still not change. Simplistic example: create a document in one word processor and open it in another and its the exact same words.
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  #15  
Old 08-22-2003, 09:20 AM
Rob Aubrey Rob Aubrey is offline
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Default Re: Apogee Rosetta 800 clocking

Hoorah!

At last I get a sensible answer, I never really thought about that!
So for my setup if I never output through any ANALOGUE domain then it will be fine!

I really thought that a better clock was gonna have a difference on my DIGITAL mixes!

I got the APOGEE ROSETTA to do the 24 bit D/A A/D thing anyway I just thought that from what people were saying in this and my other forum on CLOCKING that the stable w/c was going to make a whole world of difference to the mix.............supposedly not if it stays in the digital domain.

I'll have to think about my setup a bit more and how to implement the ROSETTA in the best possible way!

ROB
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  #16  
Old 08-22-2003, 11:01 AM
pookadilly pookadilly is offline
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Default Re: Apogee Rosetta 800 clocking

I'm glad we're all on the same page now. It is true that you will not hear much of a difference (if any) using a pre-recorded digital signal and then only using a clock reference. Clocking and conversion both play a major role in the stereo imaging of sound (hence the fact that the biggest bottleneck in any digital environment is both the clock and the conversion being used).

I would never recommend the Rosetta 800 as a studio clock only. It has a great clock on it no doubt but where it truly shines is the a/d and d/a conversion process. The reason big ben is what it is, is because it is an exceptional clock (in fact in my opinion the best clock on the planet at the moment bar none). The setup that will make a huge difference is running big ben as the master clock for all digital gear in the studio and using the rosetta 800 as for a/d and d/a conversion (basically slaving it to the big ben for clocking just as you would with all of your other digital gear).

Now, having said that I also heard mention of the fact that you really wouldn't find a use for conversion or great clocking if you were using all digital pieces. While this is true, clocking still plays a big role in the digital environment when it comes down to pops and clicks, etc. I would also say that it's a bit hard for me to believe that at no time are you ever recording sound in a studio. Anything you mic up or go in off the board (unless it's a digital console and even then a lot of the time you can bypass the converters onboard and use the apogee stuff) you are converting an analog signal to a digital one. There is no question that the conversion process is the single most important thing to getting a pro sounding mix in a digital or DAW based studio and you can't go wrong with using both big ben and the rosetta 800.

Hope that helps!
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  #17  
Old 08-22-2003, 11:20 AM
Purple power Purple power is offline
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Default Re: Apogee Rosetta 800 clocking

Quote:
Hoorah!

At last I get a sensible answer, I never really thought about that!
So for my setup if I never output through any ANALOGUE domain then it will be fine!

I really thought that a better clock was gonna have a difference on my DIGITAL mixes!

I got the APOGEE ROSETTA to do the 24 bit D/A A/D thing anyway I just thought that from what people were saying in this and my other forum on CLOCKING that the stable w/c was going to make a whole world of difference to the mix.............supposedly not if it stays in the digital domain.

I'll have to think about my setup a bit more and how to implement the ROSETTA in the best possible way!

ROB

One of the big problems with clocks is that it’s very easy to make statements about measurements without knowing what you are seeing or really listening to. As we at Apogee know very well, it’s so important to always keep questioning what results you are getting and why. Ask yourself when testing, am I seeing what I want to measure or not? With clocking tests, it is very often the case that you are not.

As stated earlier, jitter performance is only important when doing A/D or D/A conversion. For digital transfers it's only relevant when the jitter is utterly extreme, so extreme that bits get corrupted which would result in glitches (very nasty and audible obviously).

Think of jitter like an FM modulation of your audio (indeed that's what it does). If you apply exactly the same FM modulation to both channels at the same moment (which is what you did here) then you could have all of the jitter in the world and the digital signals would still cancel out (pure math). I mean if you apply nutty pitch bend on a synth and send it out to 2 channels then phase invert those and add them you'll get nothing, and yet that doesn't mean that the pitch bent sound is identical to the sound with no pitch bend applied. While this is an exaggerated comparison, in the end it's exactly the same, under a magnifying glass...

In the end, what this test tells you is that your math teachers were right; sin(a(t+dt) - sin(a(t+dt) =0; obviously whatever your dt (jitter) is it will cancel out.

That doesn't mean it's insignificant with real audio. You really don't want to be FM modulating your audio. If you look at harmonics using something other than white noise (as white noise is kind of a bad signal obviously) and apply even slight FM modulation to it everything turns from nice clean harmonics into wider bands, sort of smearing out the spectrum. It might be an exaggerated comparison, but the effect of jitter does to the spectrum something similar as blur does in graphics. And just because you are blurring you are also messing with the intricate phase relationships of the spectrum of the original signal. And our ears are very sensitive to phase as this is what gives us among other things, important clues our brains use to determine sound location, what we like to think of as stereo image.

Understanding that most folks do not have access to the equipment necessary to carry through a mathematical/scientific test that would allow you to prove this outright, our strongest recommendation is to just listen. After all, that is why we care about all of this in the first place, to make everything sound better.

In closing, Rob, I recommend using your Rosetta 800 (or Big Ben for that matter) as your master clock. While you will not notice any benefit on digital transfers, you will notice the difference when converting through the A/D and D/A.
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  #18  
Old 08-22-2003, 01:02 PM
Rob Aubrey Rob Aubrey is offline
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Default Re: Apogee Rosetta 800 clocking

Thank you for the informative replies it's great to know you all care about your products enough to search out places like the DUC to see how people are getting on in the REAL WORLD.

rob
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  #19  
Old 08-24-2003, 08:22 PM
tnie tnie is offline
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Default Re: Apogee Rosetta 800 clocking

On the new Apogee 800 and Big Ben isn't there a jitter spec or more specs than what's shown on Apogee sight?
Maybe I missed it ?
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  #20  
Old 08-24-2003, 10:38 PM
DigiGeek DigiGeek is offline
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Default Re: Apogee Rosetta 800 clocking

I finally heard the Rosetta 800 and it is everything Apogee is billing it to be. This unit is a nice improvement over my AD8000SE. the lows are tighter, the high end is more precise, and the midrange is outstanding. To me this unit sounded like what a $10K-15K converter ought to sound like. I can't believe the thing is only $3K!!!!

I was a little hesitant to believe the hype, but double blind tests do not lie and everyone in the room picked the Rosetta 800.

The metering on my 8000 will indeed be missed, but I imagine I will miss it less and less the more I hear this unit.

No matter what your favorite converter is, be it older Apogees, Prism, Lavry, Pacific Microsonics. DCS, etc. You will be amazed at how great this box sounds at any price.

THANK YOU APOGEE!!!!!
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