As ive seen with my own eyes differences in hdmi cables I thought id go hunting for any evidence as to how this could be
I came across a very well know forum yesterday that were attacking whathifi. It got my back up quite a bit but the thread was locked so I couldnt even reply (Though im thinking of posting quite a few things to upset the 'cable voodoo posse' over there)
Anyways ~
I went back to an American websight I visit every now and then. I wont post links as I have a feeling ill probably get my hand slapped (Although its not a forum so can I ?)
The author of the article is a very well respected audiophile and goes to great lengths to find 'why' things work how they do
His test has shown that jitter is influenced by all the following ~
1) the transport's jitter;
2) S/PDIF or AES/EBU interface-induced jitter (the digital interconnect);
3) how well the digital processor's input receiver rejects transport and interface jitter;
4) the input receiver's intrinsic jitter; and
5) how well the clock is recovered and handled inside the digital processor.
"My
preconception was that any measurable differences between different
coaxial digital interconnects would be marginal at best."
"What caused this reduction in measured jitter?"
"Changing the direction of the digital interconnect between the transport and the jitter analyzer."
"This
phenomenon was easily repeatable: put the cable in one direction and
read the RMS jitter voltage, then reverse the cable direction and watch
the RMS jitter voltage drop. Although I'd heard differences in
digital-cable directionality, I was surprised the difference in jitter
was so easily measurable—and that the jitter difference was nearly double."
"To
confirm this phenomenon, I repeated the test five times each on three
different digital interconnects. One was a generic audio cable, the
other two were Mod Squad Wonder Link and Aural Symphonics Digital
Standard, both highly regarded cables specifically designed for digital
transmission. The generic cable wasn't directional: it produced the same high jitter in either direction. But both the Wonder Link and the Aural Symphonics had lower jitter levels overall, but different jitter levels depending on their direction. Moreover, the generic cable had higher jitter than either of the two premium cables—even in the latters' "high-jitter" direction."
"Moreover, we can see that transport jitter goes right through the
digital processor's input receiver (even the Crystal CS8412) and
affects the amount of jitter at the DAC's word clock—the point where
jitter makes an audible difference. If the word-clock timing is
different, the sound will be different."
So to sum up this experiment ~
Cables DO induce jitter 'measureably'
Cables 'can' be directional
Digital cables are NOT the same
The receiving digital processor does NOT remove the jitter (Meaning jitter WILL effect both sight and sound)
I came across a very well know forum yesterday that were attacking whathifi. It got my back up quite a bit but the thread was locked so I couldnt even reply (Though im thinking of posting quite a few things to upset the 'cable voodoo posse' over there)
Anyways ~
I went back to an American websight I visit every now and then. I wont post links as I have a feeling ill probably get my hand slapped (Although its not a forum so can I ?)
The author of the article is a very well respected audiophile and goes to great lengths to find 'why' things work how they do
His test has shown that jitter is influenced by all the following ~
1) the transport's jitter;
2) S/PDIF or AES/EBU interface-induced jitter (the digital interconnect);
3) how well the digital processor's input receiver rejects transport and interface jitter;
4) the input receiver's intrinsic jitter; and
5) how well the clock is recovered and handled inside the digital processor.
"My
preconception was that any measurable differences between different
coaxial digital interconnects would be marginal at best."
"What caused this reduction in measured jitter?"
"Changing the direction of the digital interconnect between the transport and the jitter analyzer."
"This
phenomenon was easily repeatable: put the cable in one direction and
read the RMS jitter voltage, then reverse the cable direction and watch
the RMS jitter voltage drop. Although I'd heard differences in
digital-cable directionality, I was surprised the difference in jitter
was so easily measurable—and that the jitter difference was nearly double."
"To
confirm this phenomenon, I repeated the test five times each on three
different digital interconnects. One was a generic audio cable, the
other two were Mod Squad Wonder Link and Aural Symphonics Digital
Standard, both highly regarded cables specifically designed for digital
transmission. The generic cable wasn't directional: it produced the same high jitter in either direction. But both the Wonder Link and the Aural Symphonics had lower jitter levels overall, but different jitter levels depending on their direction. Moreover, the generic cable had higher jitter than either of the two premium cables—even in the latters' "high-jitter" direction."
"Moreover, we can see that transport jitter goes right through the
digital processor's input receiver (even the Crystal CS8412) and
affects the amount of jitter at the DAC's word clock—the point where
jitter makes an audible difference. If the word-clock timing is
different, the sound will be different."
So to sum up this experiment ~
Cables DO induce jitter 'measureably'
Cables 'can' be directional
Digital cables are NOT the same
The receiving digital processor does NOT remove the jitter (Meaning jitter WILL effect both sight and sound)