[neekomax]

Since I listen to a lot of music either by wireless streaming (to Apple TV ->toslink -> Peachtree Audio Decco DAC/Pre) or by USB -> DAC/Pre, I'm wondering if my system is plagued by the 'jitter' that I hear so much about? What does it sound like? I'm assuming I have it because my equipment isn't at the level that it has anti-jitter technology. Anyone reduced jitter in their system and can say what the difference in sound it made?

TIA, doods! 

[richidoo]

There are different flavors of jitter, just as there is different flavors of linear harmonic distortion. To me a high jitter source sounds incoherent. The clear calm presence  that you feel/hear with vinyl is not there. When jitter is cured the music becomes peaceful and powerful. In my system using stock Sonos player as digital transport there slight harshness of upper frequencies when using a DAC with poor jitter rejection. The incoherence also dulls transients which affect low frequencies too. When I use a jitter-rejecting DAC these aspects improve drastically.

I was looking for some samples online of high jitter vs low jitter recordings, but found none. I don't think it would be helpful unless you could play them on low jitter system. The observation tool has to be lower distortion than the distortion you are observing.

[neekomax]

There are different flavors of jitter, just as there is different flavors of linear harmonic distortion. To me a high jitter source sounds incoherent. The clear calm presence  that you feel/hear with vinyl is not there. When jitter is cured the music becomes peaceful and powerful. In my system using stock Sonos player as digital transport there slight harshness of upper frequencies when using a DAC with poor jitter rejection. The incoherence also dulls transients which affect low frequencies too. When I use a jitter-rejecting DAC these aspects improve drastically.

I was looking for some samples online of high jitter vs low jitter recordings, but found none. I don't think it would be helpful unless you could play them on low jitter system. The observation tool has to be lower distortion than the distortion you are observing.

richidoo, thanks for the 'coherent' () explanation of how you've experienced high and low jitter. It always helps to know what these technical terms translate to in the real world of listening experience. What jitter-rejecting DAC do you use?

[Wayne1]

Here is a very good primer on some of the causes of jitter and what it sounds like.

http://www.positive-feedback.com/Issue43/jitter.htm

As Rich states, the best way to tell if your system is "jittery" is to listen to products known to have lower jitter and compare them to what you currently have.

The Apple TV is a very well known to  have very high jitter. Perhaps you can try a different streaming device to see if you can detect the difference.

While certain DACs using the Sabre chip claim to reduce jitter it is always best to reduce it at the source.

[shadowlight]

Here is a very good primer on some of the causes of jitter and what it sounds like.

http://www.positive-feedback.com/Issue43/jitter.htm

As Rich states, the best way to tell if your system is "jittery" is to listen to products known to have lower jitter and compare them to what you currently have.

The Apple TV is a very well known to  have very high jitter. Perhaps you can try a different streaming device to see if you can detect the difference.

While certain DACs using the Sabre chip claim to reduce jitter it is always best to reduce it at the source.

Wayne,

Where does a Logitech Touch / Squeezebox 3 with stock / modified power supply fall in the jitter range.

[richidoo]

What jitter-rejecting DAC do you use?

ESS Sabre32 9018 in the form of Buffalo 2. It removes jitter inside the DA chip. This chip is used in DACs like EE, McIntosh, Sim Audio and others.

But there are other ways to reduce jitter before the DAC, like PaceCar, Stello U3, or HiFace USB. And there are DACs with good internal reclocking that reduce jitter before the DA chip, like BDA-1.

Jitter is rapidly gaining awareness among audiophiles and with that comes demand for products to deal with it, at all price levels.

[keenween]

jitter: /ˈjitər/

    

more audiocircle thoughts:
http://www.audiocircle.com/index.php?topic=51898.0

[richidoo]

Deepak, here is John Atkinson's jitter measurements for the SB3:

http://www.stereophile.com/content/slim-devices-squeezebox-wifi-da-processor-measurements

In summary he says, "The calculated jitter level was 321 picoseconds peak–peak, which is low. "

Playing the digital output into a DAC with minimal jitter rejection (Altmann Attraction) my stock SB3 sounds better than the stock Sonos. When using the Buffalo DAC they sound identical, and much better.

[shadowlight]

Deepak, here is John Atkinson's jitter measurements for the SB3:

http://www.stereophile.com/content/slim-devices-squeezebox-wifi-da-processor-measurements

In summary he says, "The calculated jitter level was 321 picoseconds peak–peak, which is low. "

Playing the digital output into a DAC with minimal jitter rejection (Altmann Attraction) my stock SB3 sounds better than the stock Sonos. When using the Buffalo DAC they sound identical, and much better.

Thanks Rich.  Will read through the article.

[Wayne1]

John Atkinson has measured the SB3, Transporter, and the Touch.

His measurement system did change a bit, but I believe the Touch has the lowest measured jitter of the three.

In comparison, I'm also including the measurements for the Airport Express and Sonos.

SB3



Transporter





Touch





Sonos ZP-80





Apple Airport Express

[neekomax]

Those measurements sure are confusing... How does one read them to mean that the Touch has lowest jitter?

[Elizabeth]

Jitter sounds like a high frequency fuzzyness.
The highs just are not clear and clean enough.
Sort of like itchy clothing. IMO. 

[Wayne1]

Here is an article about the jitter measurements and how to read them.

http://www.stereophile.com/reference/193jitter

[neekomax]

Here is an article about the jitter measurements and how to read them.

http://www.stereophile.com/reference/193jitter

Great article, thanks Wayne.

[Mike Nomad]

The Apple TV is a very well known to  have very high jitter. Perhaps you can try a different streaming device to see if you can detect the difference.

While certain DACs using the Sabre chip claim to reduce jitter it is always best to reduce it at the source.

Jitter can sound like nothing. Literally. The current iteration of Apple Airport Express have high jitter, which I found out when trying to one to feed my Peachtree Audio Nova. The manufacturer of the Nova stepped down the resolution on the second set of digital inputs, because they got so many complaints from people thinking the problem was with the Nova, instead of their source.

[neekomax]

Jitter can sound like nothing. Literally. The current iteration of Apple Airport Express have high jitter, which I found out when trying to one to feed my Peachtree Audio Nova. The manufacturer of the Nova stepped down the resolution on the second set of digital inputs, because they got so many complaints from people thinking the problem was with the Nova, instead of their source.

So what did you notice about the sound of the AEX into the Nova via Toslink? Do you still use the Nova? What streaming device do you use now?

[richidoo]

I knew the Sonos was the highest jitter digital source I ever heard, but I never saw a measurement until now. So thanks Wayne, you ruined my day. 

Just like with analog, which adds up all the different orders of distortion which all sound different from each other to give an overall THD spec, jitter has all those different sidebands which all sound different and add up to an average deviation from perfect sample timing. The Sonos has the most sideband lines and they are higher in magnitude than the others, all this adds up to more jitter.

I am glad that the ESS DAC allows me to keep enjoying the Sonos' great concept and software.

[gooberdude]

A friend of mine in chicago owns a small recording studio & went to college to be a recording engineer.  His senior year thesis paper was on jitter.  15 years ago if not longer.

Why has it taken so long to be addressed?   

[Mike Nomad]

So what did you notice about the sound of the AEX into the Nova via Toslink? Do you still use the Nova? What streaming device do you use now?

I am not parting with my Nova. It is a wonderful bit of kit, and it is not the problem. The AEX is the problem...

When the signal wasn't dropping out, it sounded great. Moving the Toslink to the second input reduced the dropouts, but didn't _completely_ eliminate them. Perhaps even worse, the sound quality from the downgraded input is crap. The AEX actually sounds better through the analog inputs than through the downgraded digital input, and the dropouts go away.

If you are considering getting a Nova (and I do recommend them), I would call them and have them send you a unit that _doesn't_ have the downgrade done to the second set of digital inputs (both the second coax _and_ Toslink are hobbled). Yes, they will do it, but you have to ask.

[richidoo]

A friend of mine in chicago owns a small recording studio & went to college to be a recording engineer.  His senior year thesis paper was on jitter.  15 years ago if not longer.

Why has it taken so long to be addressed?

Pro audio has been using word clocks to sync the entire digital chain for decades in the top studios.

I think audiophiles just have different motivations but we eventually come around....  I think that pros are financially motivated to try new technology to maintain an edge over their competition, while, in general, I think audiophiles are usually slower to warm to new ideas.