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Can the Read Speed of Micro SD effect Audio Quality? - Page 2

post #16 of 20
Thread Starter 
Quote:
Originally Posted by Ari33 View Post

I dont think it has anything to do with Card speed. The difference between reading from internal Flash memory and from an SD card is that reading from an SD card will add another layer of jitter... or simply jitter created by the additional current used or surges when reading from the SD card?

If I knew exactly what to listen for regarding jitter I could give an answer. What should it sound like? what would I be hearing. Because, I would not be surprised if this is happening from the external storage.. it sounds logical enough. Colorfly CK4+ is advertised for having a feature called Jitter kill technology of less than 100 picoseconds, maybe somethings going on there between internal and external.

I'm already using Sandisks cards. I am going to try a Samsung Class 10 next week for the hell of it. tongue.gif I'm expecting the same results though at this time.
post #17 of 20
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post #18 of 20
Quote:
Originally Posted by H20Fidelity View Post


If I knew exactly what to listen for regarding jitter I could give an answer. What should it sound like? what would I be hearing. Because, I would not be surprised if this is happening from the external storage.. it sounds logical enough. Colorfly CK4+ is advertised for having a feature called Jitter kill technology of less than 100 picoseconds, maybe somethings going on there between internal and external.
I'm already using Sandisks cards. I am going to try a Samsung Class 10 next week for the hell of it. tongue.gif I'm expecting the same results though at this time.

 

 

Steve Nugents description of Jitter from the link bellow..

 

"Most audiophiles do not even realize that they have jitter until it is reduced. I liken it to looking through a window made of really old glass, when glass had ripples and bubbles in it. There is a spreading and distortion that widens and defocuses some images and creates an overall mild distortion. It is still obvious what is on the other side of the window, but it is not coming through with crystal clarity. Reducing (you will notice that I do not say "removing") jitter is like replacing the glass with a clean, flat piece of glazing. Things are now visible in great detail and with a "vividness" that was not there with the rippling glass. Jitter can be blamed for much of the "fatigue" that results from listening to some digital playback systems, just like it is fatiguing peering through rippled glass for any length of time."

 

I cant find any recordings of Jitter but there is a good article on the various types/causes in this link-  http://www.positive-feedback.com/Issue43/jitter.htm

 

 

 

I'd hazard a guess that Sub heading No 6 - 'Power subsystem' induced jitter which could be caused by the additional voltage/current/surges when reading from SD card, is probably the root of your problem. I can be cynical at times but It isn't unusual for manufacturers not to tell the full story, ie; The 100 Picoseconds figure mentioned was most likely measured when reading from the internal flash only.

 

6. Power subsystem

The DC power applied to each of the devices that must process or transmit the digital audio signal is critical. If this power varies in voltage, the devices will react differently to the applied digital signals. Power "noise" as it is referred to is probably one of the largest contributors to jitter. Voltage changes or "voltage droop" can happen anywhere on a circuit board, power cabling, or even on the silicon itself. Changes in power voltage will change the speed and reaction times of digital logic that is transmitting the digital signals resulting in jitter."

 

 

Of course, I could be completely wrong I'm just really interested to learn about what the causes might be, Keep us updated...

 

 


Edited by Ari33 - 12/9/12 at 2:28am
post #19 of 20

I've also just read over your initial posts link to the other thread;

 

Could it be that the FAT formatted file cluster sizes could cause different levels of voltage droop in this particular circuit design creating jitter at different clock speed frequencies depending on the cluster size.. and add credence to the above theory?  

If so this points to a circuit design flaw with the player, sheer laziness in not bothering to ensure their anti-Jitter circuitry also worked with the SD card path and/or its additional current/voltage parameters, As it sounds like you are all experiencing it with the same model.

post #20 of 20
Thread Starter 
Thanks for the info Ari33.

I can't say that's exactly what I'm hearing from microsd, certainly feels like there's a slight power drop though, sound becomes a touch grainy, loses some smoothness, also becomes a touch brighter or shrill, it loses that refined edge also thins out quicker at higher volumes. I guess you could say blurred or fuzzy. Jitter seems the reasonable explanation, differences are rather small amount, some won't notice but to me I can hear the difference. I think the DAP is to blame running from external storage. If this is the case really there's no solution. I can't say yes yes! that's exactly how it sounds...

By all means it still sounds very good, not excellent like the internal though.
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