Not the result I got, but I was looking at raw bit stream to see how much error correction and buffer size would be required for a recent project.
The real issue turned out to be recreating the clock rate.
Yes, of course there are limits. I never said otherwise. I was simply answering Richard's question as to how we know what data was put on the disc originally.
Yes. But we can be assured when correction is not possible.
Yes. And it still works amazingly well. As I said in my previous post, unless the disc was in rather bad shape, C2 error correction failures are quite rare, even on the cheap Yamaha player I had back in the late 80's whose decoder chip had a C2 error fail flag pin on it which I used for monitoring.
se
I guess that one of the differences between a data disk and an audio disk is that the data disk does not need to have absolute correctness in the timing, or the jitter is not a problem, just that the actual bits are exact, bit for bit.
The audio disc doesn't have to have absolute correctness in the timing either. Where you want absolute correctness in the timing is when the DAC chip makes its conversion.
se
Steve
One infrequent case is when multiple errors occur so that the parity is not changed. These errors do go undetected.
C2 errors are actually less common today among quality manufactured CDs. However I have some that were sold as a set from a low cost producer that has copious errors resulting in some surprisingly long drop outs and even distorted sound!
But the actual question was does spindle misalignment increase errors and I think the accurate answer is that it will change raw bit errors.
One infrequent case is when multiple errors occur so that the parity is not changed. These errors do go undetected.
C2 errors are actually less common today among quality manufactured CDs. However I have some that were sold as a set from a low cost producer that has copious errors resulting in some surprisingly long drop outs and even distorted sound!
But the actual question was does spindle misalignment increase errors and I think the accurate answer is that it will change raw bit errors.
Requiring a buffer that is long enough to handle the difference. Otherwise the negative half cycles end up on the East coast and the rest West.
Got a cite for that?
C2 errors themselves aren't a problem. A C2 error can be corrected. It's when they're not able to be corrected they can be problematic.
I'm sure it could.
se
That's not required. The redundant data in itself carries enough information to identify, figure out and perfectly correct errors of up to 4000 consecutive mutilated bits. There's about three times as much data on the disk than required for the audio. Some is overhead and housekeeping, most of it is redundant stuff cleverly coded to provide error correction.
It really IS perfect.
jan
Thanks for the answers. I guess this is where single bit and multi-bit and oversampling starts to come into the conversation but this all seems to be getting farther and farther from the BT thread and audio circuits, so I will desist from asking any more questions about the subject now. Time to go back and read more........
Disclaimer : all references to fetishism and related items, are figments of your own imagination, any correlation to real of virtual participants of this thread, is purely coincidental.
Somewhat of a surprise that +3 decades after the introduction date of the CD medium, such facts are still not general knowledge in the audio realm.
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Just to ruin SY's day here are some of my measurements of a 500mA fuse mounted in a panel mount fuse holder and tested with DC. The voltage measurements are after 10 seconds of the applied current. The resistance grows as time goes by at the higher currents. When the table stops is where the fuse blew.
BTY the rule of thumb for woofers is that when the impedance more than doubles you are just about to blow it! The actual limit is based on I squares times T.
Dick as you can see this fuse would introduce several percent distortion in the LF energy of a loudspeaker! And yes a time delay fuse has more thermal mass and less distortion.
Steve that is basic to any error correction. Some errors will mimic valid data.
BTY the rule of thumb for woofers is that when the impedance more than doubles you are just about to blow it! The actual limit is based on I squares times T.
Dick as you can see this fuse would introduce several percent distortion in the LF energy of a loudspeaker! And yes a time delay fuse has more thermal mass and less distortion.
Steve that is basic to any error correction. Some errors will mimic valid data.
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They used to have a kind of fuse where the increase in resistance with current was actually exploited - I think they were called 'incandescent lamps' 😉
ES,
Can we safely assume that this same phenomena would happen whether a fuse or a relay? Rising distortion with rising voltage or current?
Can we safely assume that this same phenomena would happen whether a fuse or a relay? Rising distortion with rising voltage or current?
No a relay will follow Ohms law. A fuse or light bulb does not. As a result a fuse or light bulb will add distortion. An ohmic device will not. It just adds loss.
But there is a very interesting phenomina that occurs with fuses that is shown in the chart!
I would presume that a fuse is deliberately made nonlinear to optimize its primary task. We have known about slow blow vs fast blow for more than 40 years. It just makes sense, AND we could HEAR IT. Ask John Meyer about it, sometime, if one of you is in doubt. (Not you Ed, thanks for the actual measurement)
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