Ripped Audio vs. CD audio... Throwing Down the Gauntlet !!!

OO, please answer me one question, a simple "yes or no" will do.

2 identical digital streamed signals coming from any 2 sources (should) be equal?
Not saying they (will) be equal, but that they "should" be equal.

OO, please answer me one question, a simple "yes or no" will do.

2 identical digital streamed signals coming from any 2 sources (should) be equal?Not saying they (will) be equal, but that they "should" be equal.

I'll answer that for you James. Any two things that are "identical" will, by definition be "equal".

But I think you are asking if there will be a difference in the same digital signal coming from different sources.

The signal will be equal unless acted upon by something different in one of the sources. The clockling circuitry for example.

But the signal....1's & 0's will be the same.

That was going to be my point in the end. Both signals should be equal, and if they are not, it is due to something the source is doing wrong... ie. jitter, error correction and so on.

The point being, regardless of the equipment, the 2 signals should be the same unless one is doing something wrong to change the signal... 111000111 should equal 111000111 regardless of the source.

CD Transport - Logitech Transporter - CD-Rom - Hard Drive, should all be sending the same digital 1's & 0's
None of the units should be introducing any "signature" at all. If they are, something is wrong.

And if all is equal, and both units are sending identical signals as they should be, there should also be no audible difference in the end.

I just don't understand why OO continues to try to say the test is "not credible or invalid"
His version, of running his PC, CDrom and HDD as sources, wouldn't be any different. The CDrom could and would introduce jitter or error correction, just as easily as our sources.
In the end, his version would actually be sending the data through more hardware and cables than ours. No need for a PC in the middle, or the USB to RCA to preamp....

OK, I am worn down and no longer care how you are having fun.

Two different sources will create different jitter. Maybe it will be not enough for Tom's ears to measure, maybe it will.

If all go through the same DAC, that helps, but it still leaves room for discussion.

I just don't see why you don't take the simple route as it is simple.

Actually I do as I have posted before.
You are comparing a high end CD player to your thingy.

I like that!!!

It will not be the truest test of a CD against a ripped CD, but it will be great fun --

You just read here what you want and disregard posts like Mark put up.

So, I am now, on this post, admitting you are right and the rest of us are wrong.

I am now, on this post, admitting you are right and the rest of us are wrong.

About time !!!!!

Wait a minute. I thought that jitter was introduced when the original CD was read from the laser. If this is correct, then both sources [original CD and subsequent "copy"] would have the same jitter originally introduced. Since the DAC in this test is built into the preamlifier, and the jitter is in both the original and it's subsequent "copy", then the jitter will be the same.

Someone in the know PLEASE correct me if I am incorrect in this assumption. I'm not trying to beat the poor horse that died a couple of pages back, I would really like to know. Could someone be so kind as to answer this one [assumingly] simple question?

Not quite...

The laptop that will do the CD ripping, will be using Exact Audio Copy software (EAC)

EAC will re-check the ripped file up to like 175 times if needed, to ensure the ripped file is perfect to the data on the CD.

I could be wrong here, but I don't think the ripped file will have ANY jitter. The EAC software makes sure of it.
As where the CD Player laser has to try to fix errors on the fly as it's playing.
When the PC file is payed back, there is no laser in the way to try to fix errors that have already been taken out.

Not 100% sure of all that, but I think it's right.
I'll do a little more reading and report back here.

Any spinning drive / device can introduce jitter on digital media. (wow and flutter on LP media) CD drive included. James - you understand SFM (surface feet / minute) having an NC router right? Outside dia spins much faster (SFM) than inside dia - even adjusting for this to keep a constant speed (like on a CNC lathe) there still could be a lag in the laser pickup. Make sense?

Tom,

The laser reading does have jitter. If it's a steady "stream" to a DAC, that's where you have jitter trouble of unstable timing. However, if you're reading it as "data" and building a file or stacking it into a buffer....not trying to get a stable feed to a DAC, then you've avoided the big part of the problem.

Maybe a way to try to keep all the various methods of digital play and jitter in mind is to think of it those two ways...streaming the digits to a DAC versus reading 1's and 0's in a off-line kind of way.

I'm short on time to think about it right now, hope that makes sense.

Mark

Not quite...

The laptop that will do the CD ripping, will be using Exact Audio Copy software (EAC)

EAC will re-check the ripped file up to like 175 times if needed, to ensure the ripped file is perfect to the data on the CD.

I could be wrong here, but I don't think the ripped file will have ANY jitter. The EAC software makes sure of it.
As where the CD Player laser has to try to fix errors on the fly as it's playing.
When the PC file is payed back, there is no laser in the way to try to fix errors that have already been taken out.

Not 100% sure of all that, but I think it's right.
I'll do a little more reading and report back here.

You seem really big on EAC. It is good, but so are many others. EAC owns no secret, not a Harry Potter wand - -> that is the snake oil -
Think about it -
If you are hoping your ripped copy is jitter free, then the only way that could be possible is that if the CD Tom will start with and you copied from is jitter free. So Tom has a leg up from the start.

None of that has anything to do with jitter, but it is logical if this is the way it works in the EAC dimension.

In the real world, I don't see jitter from most sources being a problem for Tom's ears. In these cabin settings, I doubt a big eared Elf could discern the jitter difference. This will all be good equipment, so just disregard that factor for "ear" tests.

Well I'm excited to finally get a raceme test going finally. I think this well be the 3rd or 4th year we have talked about it, and finally all the duckscare in a row.

Yu might want to bring your PC and DAC over too.. We can try the test both ways.

A "bit" sitting on a disk (CD or hard) has no jitter. It is either a 0 or a 1. Streaming them out creates jitter, passing them through wires creates jitter, etc.

A "bit" sitting on a disk (CD or hard) has no jitter. It is either a 0 or a 1. Streaming them out creates jitter, passing them through wires creates jitter, etc.

And there are many "wires,etc" in play here (think motherboards, soundcards, and things inside the players the signal passes through, not just the connectors). Plus, a different thing will be reading the files. A CD even turns at a different speed than your hard drive. In most good stuff, there is a buffer to help, but those will be different too. I believe the files will be the same. Using different equipment to test that is testing equipment.

I am not sure under the proposed tests that Tom or anyone can consistently pick which is which in a blind test.
If he can, it means your equipment sounds different from his CD player, not that ripped files and unripped files played from the same equipment sound different.