I made one very interesting discovery regarding the service hidden menu in my JVC XV-N33SL DVD/CD Player. 😉
It does current measurement in mA of the current that the laser beam is using at CD or DVD mode, it has stored the factory activation measurement and presenting it side by side to the real time one, as comparison point of the condition of the laser diode.
In my case it is still bright new!!
Additionally it can measure Jitter level caused by its one CD media, and this helps as benchmarking tool.
Unfortunately I am not aware of which measuring units it is using.
I get four numbers which I am speculating that seems as pico-seconds in high resolution.
I have read that 200 Picoseconds is a good upper limit regarding Jitter.
In my first test I did use two commercial music CD discs that came together in a dual CD pack (Made in Germany 1990) the test mode measured values as 1758 fluctuating to 1755 in both of them.
In my second test I had use a Verbatim CD which I recorded before two years and this measured 1300.
I would appreciate some incoming enlighten regarding CD media quality testing just for the parameter of CD media Jitter.
It does current measurement in mA of the current that the laser beam is using at CD or DVD mode, it has stored the factory activation measurement and presenting it side by side to the real time one, as comparison point of the condition of the laser diode.
In my case it is still bright new!!
Additionally it can measure Jitter level caused by its one CD media, and this helps as benchmarking tool.
Unfortunately I am not aware of which measuring units it is using.
I get four numbers which I am speculating that seems as pico-seconds in high resolution.
I have read that 200 Picoseconds is a good upper limit regarding Jitter.
In my first test I did use two commercial music CD discs that came together in a dual CD pack (Made in Germany 1990) the test mode measured values as 1758 fluctuating to 1755 in both of them.
In my second test I had use a Verbatim CD which I recorded before two years and this measured 1300.
I would appreciate some incoming enlighten regarding CD media quality testing just for the parameter of CD media Jitter.
The jitter is not recorded onto the media, the media just contains the data, it is static on the disc so can have NO jitter, jitter is a dynamic thing and can only be present when data is being transferred from a to b as synchronous data transmission, you need a clock so you can get jitter.....
No I am not confused regarding the different sources of Jitter, and the master clock Jitter is not at the center of my interest this time.
From the other hand I am open to every possible explanation of why this Jitter measurement changes?
1) Is it Jitter due errors at the master clock which was recorded on that CD media due it manufacturing process?
2)Is it Jitter caused by the clearness level (transparency) of its CD media?
In this case the laser diode will use a minimum current when reads the disc, and fewer reading errors will arrive to the DAC too.
From the other hand I am open to every possible explanation of why this Jitter measurement changes?
1) Is it Jitter due errors at the master clock which was recorded on that CD media due it manufacturing process?
2)Is it Jitter caused by the clearness level (transparency) of its CD media?
In this case the laser diode will use a minimum current when reads the disc, and fewer reading errors will arrive to the DAC too.
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