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Old 9th November 2013, 01:41 AM   #1
jogi59 is offline jogi59  Germany
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Default A simple question - How does Jitter sound?

I never hard Jitter. What should I pay attention to?
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Old 9th November 2013, 12:27 PM   #2
oshifis is offline oshifis  Hungary
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It is not possible to hear jitter, you can hear only the effect of jitter.
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Old 9th November 2013, 02:51 PM   #3
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Why not go over to the 'sound science' section of head-fi and find stv014, who has a standing offer to add jitter to any short musical clip sent to him by anyone who wishes to see if they can hear the effect. I believe he has some existing clips downloadable too.
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Old 9th November 2013, 03:20 PM   #4
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It depends on the frequency spectrum and the amount. The effect is quite similar to intermodulation distortion (IMD). I've heard it said that it makes the treble sound harsh or muddled, or makes cymbals or piano music sound artificial. However, to degrade the sound audibly you need about 100x more jitter than a good quality DAC can manage. A faulty SPDIF connection or a USB DAC with a dodgy driver might do it though.

You can't add jitter to a digital file. All you can do is add IMD to mimic the effect of jitter.
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Old 10th November 2013, 08:36 PM   #5
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In my experience it mostly decreases the perceived stereo separation, making stereo sound more like mono, as well as obscuring a bunch of low-level sonic information.
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Old 10th November 2013, 08:41 PM   #6
Pano is offline Pano  United States
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There is a jittered signal on one of the Stereophile test CDs. Disc 2, I think.
Listen to that and tell us what you think. Or try having someone add it to your clips, as stated above.
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Old 11th November 2013, 12:30 AM   #7
wa2ise is offline wa2ise  United States
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Quote:
Originally Posted by scopeboy View Post

You can't add jitter to a digital file. All you can do is add IMD to mimic the effect of jitter.
One thing you could do is take the output of a jittery DAC and redigitize it. Maybe using a different or higher sample clock, and store that uncompressed as a file, and replay it at that higher clock rate into a low jitter DAC built to accept that higher clock rate. .

Or you could substitute, as a test setup, the player's master clock oscillator with an RF signal generator that can do FM modulation (which is a form of jitter). And then play some selected music or just a test tone CD.

I try to locate a simple crystal oscillator of the desired clock frequency close (electronically) to the DAC chip. Crystal oscillators not part of a PLL are usually low jitter. The rest of the CD player digital circuits are just shuffling bits, and a little jitter there is of no consequence. External DAC boxes should really have housed the master clock oscillator, and use say a S-video cable (has a pair of 75 ohm coax cables in it, one for the DAC box to send clock to the transport, and on the other the transport sends the music bits to the DAC box). And the DAC box would reclock those bits to remove any jitter before it hits the DAC chip inside that DAC box.
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Old 12th November 2013, 02:30 AM   #8
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My experience tells me, generally, that higher jitter makes for added coarseness and lack of clarity in the vast majority of ladder dac units, and loss of impact in bass and progressively weakened dynamics further up the spectrum in nearly every dac based on one form or another of bistream.
I do my jitter sensitivity testing by means of the tried and true "crappy versus excellent transport" method. In the last ten years, I've used my upgrade of the Museatex C-Lock CDD as the "excellent" for testing(still my favorite transport) and just about ANY dvd player as very conveniently bad transports for the purpose.
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Old 12th November 2013, 03:02 AM   #9
mitchba is offline mitchba  Canada
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Quote:
Originally Posted by jogi59 View Post
I never hard Jitter. What should I pay attention to?
Try the jitter listening test and then check out the results.

Cheers
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Old 15th November 2013, 10:49 PM   #10
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would hi res flacs be ok?
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