Yep, but getting it right first is the best bet, with simulation you can engineer the solution before hand, modelling any termination that may be required. Though for SPDIF both are probably overkill and how many on this site would have either at there disposal, I don't have a TDR, though.
Using a TDR you would have to set the pulse to match the driver output.
Using a TDR you would have to set the pulse to match the driver output.
For spdif sort of speeds, most of us have a scope that is quick enouth and a signal generator buffered with a 'AC04 or such will, if fed to the cable via a suitable resistance and a bnc T on the front of scope make a simple minded TDR (Also quite useful for finding the distance to a short in a installed 75 ohm line).
Sure a proper fast TDR is nice, but you can improvise ways to do these tests.
My take on it is that if a different basically competent cable makes a difference then either the transmitter or the recever (or both) is sub standard (Possibly a clock recovery problem or something), a cable and its driver/recever can at best be transparent, if it makes any difference it is because something in the chain is not fit for purpose.
Now, those of us familiar with these methods wont bother, because figure we understand at least enough, and the guys advocating silver wire for a low speed manchester coded link will not do them because they lack the RF and signal integrity skills to understand the results.
Regards, Dan.
Sure a proper fast TDR is nice, but you can improvise ways to do these tests.
My take on it is that if a different basically competent cable makes a difference then either the transmitter or the recever (or both) is sub standard (Possibly a clock recovery problem or something), a cable and its driver/recever can at best be transparent, if it makes any difference it is because something in the chain is not fit for purpose.
Now, those of us familiar with these methods wont bother, because figure we understand at least enough, and the guys advocating silver wire for a low speed manchester coded link will not do them because they lack the RF and signal integrity skills to understand the results.
Regards, Dan.
I like to adhere to white papers, designs based on analytical research and objectivism.
But I also allowed myself to trust my observations. It didn't happen quickly or early enough in my life, but luckily - it did happen. Try to listen to a pure silver, properly constructed SPDIF cable. The speed, amount of detail, natural presence and space will blow you away. 90% of people who heard these cables were completely unprepared when presented with such sound. The rest of the system has to be very, very good.
The SPDIF cable I've been referring to in this thread is very expensive. If I see the opportunity to sell it, and if the customer is a believer willing to pay, the accessories that come with the cable at no extra cost are the installation of high quality pulse transformers at both ends of the signal chain. That is indeed as important as the cable itself.
Boky
again I am cynical, how would silver make any difference...
Hah pulse transformer....so its not just a cable.
Now don't tell me, let me guess: those people knew that a silver cable was being demonstrated, or at least the presenter knew?Extreme_Boky said:
Ah, the standard 'high-end' get-out clause: if you can't hear it that means your ears/system/brain is not good enough to hear what more sophisticated/wealthy/gullible people can hear.
Now I understand.
One of three, to be fair.
1. Your system isn't good enough.
2. Your ears aren't good enough.
3. You don't know what live music sounds like.
Expect 2 and 3 next, though the order often changes.
IMHO, the best cable I could measure in "jitter terms" with my tektronix, is the Canare LV61S. The good news: is very cheap
Canare Corp.: 75 ohm Coaxial Cable: 75 ohm Video Coaxial Cable(LV-61S)
Also Canare have 75 Ohm RCA
Canare Corp.: RCA Crimp Plugs: 75 ohm RCA Crimp Plug(RCAP-C Series)
Canare Corp.: 75 ohm Coaxial Cable: 75 ohm Video Coaxial Cable(LV-61S)
Also Canare have 75 Ohm RCA
Canare Corp.: RCA Crimp Plugs: 75 ohm RCA Crimp Plug(RCAP-C Series)
Somewhat surprisingly (to some people) good cables usually are quite cheap, as they are simply using good commercial quality cables and connectors which are carefully assembled. If you want a really bad cable you have to pay very little or quite a lot!ramallo said:
No, RCA is not 75 ohm and cannot be. My guess is that it is actually lower than that, as the centre pin is quite thick.
I suppose with careful EM modelling it might be possible to arrange tails or other compensating components (of a higher impedance) so that the combination of those plus RCA is a reasonable approximation to 75R provided the frequency is not too high. I doubt if anyone has bothered to do this as for SPDIF it is not really worth it. It is one of those cases where those who know how to do it know it is not worth doing.
I suppose with careful EM modelling it might be possible to arrange tails or other compensating components (of a higher impedance) so that the combination of those plus RCA is a reasonable approximation to 75R provided the frequency is not too high. I doubt if anyone has bothered to do this as for SPDIF it is not really worth it. It is one of those cases where those who know how to do it know it is not worth doing.
Still would be curious to know why some think silver would be better for digital signals and by what mechanism...?
you don't.
the silver cable was vastly superior in every sense. the difference is obvious to anyone who might be around - not just to people who listen, the stunned, jaw dropped effect is immediate within only few seconds of A-B comparison. This is WITHOUT the pulse transformer mod; this mod follows after, once the cable's being sold.
Silver is:
more expensive than copper
more shiny than copper
has slightly better conductivity than copper (so is used to plate high-Q UHF resonators)
is used for jewellery
so it is obvious that it must sound better than copper! Only a deaf engineer with a useless audio system could possibly think otherwise.
There is one way a silver digital cable might (just) sound different from a copper one: it could be slightly less lossy so there could be slightly more reflections so jitter could be slightly worse so the sound could be slightly worse. Unlikely to be audible though.
Just thought of another issue: if the silver cable also has a teflon insulator (I understand these often partner each other in 'audiophile' cables) then it is possible that triboelectric effects make the cable somewhat microphonic which could upset the data slicer at the receiver end and cause more jitter which would be signal-related (but slightly delayed). In a bad situation this might be audible and would get worse as the volume is turned up. Some people might confuse the resultant distortion and muddying with extra detail.
more expensive than copper
more shiny than copper
has slightly better conductivity than copper (so is used to plate high-Q UHF resonators)
is used for jewellery
so it is obvious that it must sound better than copper! Only a deaf engineer with a useless audio system could possibly think otherwise.
There is one way a silver digital cable might (just) sound different from a copper one: it could be slightly less lossy so there could be slightly more reflections so jitter could be slightly worse so the sound could be slightly worse. Unlikely to be audible though.
Just thought of another issue: if the silver cable also has a teflon insulator (I understand these often partner each other in 'audiophile' cables) then it is possible that triboelectric effects make the cable somewhat microphonic which could upset the data slicer at the receiver end and cause more jitter which would be signal-related (but slightly delayed). In a bad situation this might be audible and would get worse as the volume is turned up. Some people might confuse the resultant distortion and muddying with extra detail.
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Extreme_Boky, why is silver better than copper in this instance, what are the mechanisms that make it so superior...
That is no answer, with digital you cannot just listen, you have to have empirical data, it maybe that the silver cable is causing the bit pattern to change thus adding noise.
You cannot make a claim without some evidence about what is going on...I know many Audiophiles find this hard to believe, but Audio reproduction electronics has to follow the same rules of physics as every other field of electronics....
That is no answer, with digital you cannot just listen, you have to have empirical data, it maybe that the silver cable is causing the bit pattern to change thus adding noise.
You cannot make a claim without some evidence about what is going on...I know many Audiophiles find this hard to believe, but Audio reproduction electronics has to follow the same rules of physics as every other field of electronics....
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