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Jitter, CDPs, Transports and Streaming

In my personal, digital audio journey, I have found that I prefer the sound of CD players over streaming through my computer to a DAC. I have tried 4-5 different steaming/transport configurations and found CD players to sound more natural with less digital glare and cause less listener fatigue in each comparison I made. I attribute this to jitter and the increased levels caused by noisy computer environments and the additional circuitry and wiring between a source/transport and DAC. I am sure component quality plays a role here and I’m sure there are CD transport and DAC combinations that sound better than some standalone CD players.

I got to thinking that DACs have buffers that they read from and realized that the upstream source shouldn’t matter, but they apparently do. Why doesn’t the buffer completely eliminate the relevance of the quality of the source? Are there types of DACs, like asynchronous DACs, that make the CD transport or computer source quality irrelevant?
128x128mkgus
audioengr
3,282 posts
 

Every source, whether it's a Transport or a computer server will sound different because the clock circuit designs are different.  Some are better than others, so they will have lower jitter.  A DAC that reclocks asynchronously will usually be affected by this jitter. I have only evidence of one DAC, the Benchmark DAC3, that is generally immune to incoming jitter, but this conclusion is only anecdotal based on customer feedbacks.  I have not tested this myself.

Steve N.


Empirical Audio

mzkmxcv
777 posts
 
I have only evidence of one DAC, the Benchmark DAC3, that is generally immune to incoming jitter

It’s J-Test shows jitter reduction at >-148dBFS, amazing. However, the $77 Topping D10’s J-Test shows reduction of jitter down to -128dBFS. So, if they hear no jitter on the DAC3 and do hear jitter on any other competent DAC, it’s simply placebo, as our hearing in even a treated room is not better than 100dB.
teo_audio
2,197 posts
 
Noise floor and dynamic ranging capacity have little to do with being able to hear jitter in a signal. The two have no direct correlation, only minimal aspects of correlation.

Reclockers or reclocking designs, chips, circuits and said implementations of such... can make for worse jitter going in (to the dacs proper), than was originally received from the given source point, so one has to be careful. Re-clocking is not a wonder ointment cure-all. It is generally considered to be a good idea but it does, or can... create a brick wall jitter reduction effect, that the reclocker is then crowned the king of jitter issues for that system.

Being able to hear jitter changes as pass through from the one device to another, is a good sign, generally (but only possibly!), that less jitter harm is being done by the receiver as the jitter changes upstream are not being swamped by intrinsic jitter noise, but it does not mean that intrinsic jitter problems of the receiver do not exist. It means there is some minimal transparency aspects. For better or for worse.

Meaning, in clarity, that when I read about a device having a reclocker that offers low jitter, and it is stated that it ’fixes everything’... I remain wary and suspect of it’s purchase and/or use, as this means I’m quite possibly brick-walled in my attempts to try and fix jitter in the entire final usable pathway, via upgrades in source point or digital cable choices. But again, only possibly. It all remains as a crap shoot. Nothing new.....
mzkmxcv
777 posts
 
@teaudio

Noise floor and dynamic ranging capacity have little to do with being able to hear jitter in a signal. The two have no direct correlation, only minimal aspects of correlation.

Jitter in a system results in a raised noise floor and possibly power supply noise. The only way to hear jitter is if you have a low enough noise floor. However, jitter thru wired connections has been pretty much a non-issue for years.
audioengr
3,282 posts
 
Reclockers or reclocking designs, chips, circuits and said implementations of such... can make for worse jitter going in (to the dacs proper), than was originally received from the given source point, so one has to be careful. Re-clocking is not a wonder ointment cure-all. It is generally considered to be a good idea but it does, or can... create a brick wall jitter reduction effect, that the reclocker is then crowned the king of jitter issues for that system.

There are certainly poor reclockers and good ones. Reclocking is a great cure-all actually, if it is done right. Measuring the jitter directly at the end of a 4 foot cable is not what most vendors do, because it requires specialized, expensive equipment. This is what I do, so my measurements speak for themselves. Many, many customer feedbacks also speak volumes. You can read all of these yourself.

The other benefits of reclocking are usually glossed-over, including input and output galvanic isolation and upsampling to 24/96 so the DAC uses a better digital filter. These are all benefits of the Synchro-Mesh.

Among my own products, which all deliver extremely low jitter, less than 10psec at the end of a 4 foot cable, my Synchro-Mesh reclocker actually delivers the lowest jitter. The artifacts created by upsampling to 24/96 by the Synchro-Mesh are minimal too, really insignificant compared to eliminating the jitter. Most don’t hear anything due to the upsampling, just better SQ.

Steve N.

Empirical Audio

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