affordable & easy way to measure jitter?
Can anyone kindly advice what is affordable and easy way for a non-techie guy like me to be able to extract jitter measurements from various transports / pc playback software?
I find that sound quality of digital players/devices are highly influential from the way a track is cued up and played. I would like to know of simple solutions to quantify my findings.
TIA!
Can anyone kindly advice what is affordable and easy way for a non-techie guy like me to be able to extract jitter measurements from various transports / pc playback software?
I find that sound quality of digital players/devices are highly influential from the way a track is cued up and played. I would like to know of simple solutions to quantify my findings.
TIA!
Hi jerome123,
Once a PC delivers the data, it's been clocked out by it's own clock. You could probably measure the jitter of that clock, but which one and how do you access it? You need to be a technician in order to find and connect to the test points.
The same issues apply to a CD player or DAT machine - whatever. You need to access the test points of interest, then there is the complication of what jitter the drive suffers from and how that impacts the data. By the time it appears at a port, it's been re-clocked and so those measurements are pointless really.
Now for the granddaddy of problems. Jitter is measured by comparing the signal in question to a very low jitter clock source. That's going to cost to begin with. We can use a PLL to show the jitter in the servo signal, but then there is often a weighting (filtering) factor that tends to reduce the peak jitter. You are looking at costly equipment to do a proper job. I do have a counter that does display jitter, and it's expensive (HP 5335A). I don't bother since I can't really change the jitter, and I'm not sure what weighting they want to use. All we can do is minimize the amount of jitter where we can access it, normally in a mechanical system. A clock source with excessive jitter is broken, that's a fault we fix. Again, a job for a technician.
-Chris
No, it's not possible.
Once a PC delivers the data, it's been clocked out by it's own clock. You could probably measure the jitter of that clock, but which one and how do you access it? You need to be a technician in order to find and connect to the test points.
The same issues apply to a CD player or DAT machine - whatever. You need to access the test points of interest, then there is the complication of what jitter the drive suffers from and how that impacts the data. By the time it appears at a port, it's been re-clocked and so those measurements are pointless really.
Now for the granddaddy of problems. Jitter is measured by comparing the signal in question to a very low jitter clock source. That's going to cost to begin with. We can use a PLL to show the jitter in the servo signal, but then there is often a weighting (filtering) factor that tends to reduce the peak jitter. You are looking at costly equipment to do a proper job. I do have a counter that does display jitter, and it's expensive (HP 5335A). I don't bother since I can't really change the jitter, and I'm not sure what weighting they want to use. All we can do is minimize the amount of jitter where we can access it, normally in a mechanical system. A clock source with excessive jitter is broken, that's a fault we fix. Again, a job for a technician.
-Chris
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