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Discussion Starter · #1 ·
Anyone having a good way to make such a cable? I was asked on a another forum, but this is the place.


How would the sound quality in such a cable be versus an expensive one. Anyone tried it on a high end system.


He is also concerned about sound quality from a HTPC versus a standalone player. Should he worry?


I tried a search, but I got too many treads to look into.


I am sure someone has done before this so just send me there.
 

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Buy a good-quality-coax-cable and two RCA-plugs (or a mini-jack and a RCA-plug depending on your needs) and with a little soldering you've got one hell of a SP/DIF cable. Can you hear the difference with a professional cable? I don't know. A trained ear can hear more than an untrained one, but I don't hear the difference (yet). Just try it and if the result is good enough for you then you save yourself some money.
 

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Find a RCA video cable, and a mini-plug cable. Take a knife, chop the two, and splice them together. Bind with electrical tape.


The trained ear can't hear squat. This is a digital signal, not analog. It either will work, or it wont. :)
 

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You can also order a custom made cables from www.markertek.com or www.bettercables.com . I believe they will make any length if they don't carry the length you want. I have purchased shorter SPDIF cables from MarkerTek and they seem to be very good quality at a reasonable price.
 

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I am using an ordinary RG-6 cable with F to RCA adapters for a 35 ft. run and it sounds perfect. This is a very cheap an inexpensive way to make a SPDIF cable. BTW, these cable also work pretty well for composite video and analog audio.


Jay
 

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Is the impedance of a RCA, line level, analog audio output found on a VCR

75Ohms? I believe it is not. So, if I am correct, using RG6 (75Ohm) cable

for this kind of connection would cause an impedance mismatch...


What side effects (if any) could be caused by this type of impedance mismatch?

Could the electronics on either end of the cable possibly be damaged?

What about sound quality?


HobbieMan
 

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Although my EE knowledeg is limited, IIRC the current carried by a standard audio interconnect is so low as to render the actual impedence of the cable negligible. It is supposed to be approx. 100 ohms, but the real world difference between 75 and 100 ohms in this application is not important. This is in opposition to video cable, where an impedence mismatch can cause ringing and other artifacts.


I'm sure someone could correct my actual scientific expanation, but all that really matters is that the impedence of line level audio interconnects is largely irrevelant.
 

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The impedance of standard RCA audio is 10's of K-ohms. The impedance of the cable is irrelevant at audio frequencies. However the data in the S/PDIF connection is several MHz, so it does matter in a longer cable run. S/PDIF is 75 ohms though, so standard audiovisual video hookup cables are fine.


Kon is absolutely right, S/PDIF is a digital signal, it will either work or it won't. Anyone that buys expensive "specialist digital audio cables" has been duped.


Keith
 

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You can buy RG59 (or may be RG6) shielded coax properly terminated with RCA connectors at 50 ft (~$29) or 100 ft from You Do It electronics ( www.youdoit.com ).


I have a 50ft one from my Soyo Mobo SPDIF to my receiver, works great.


steve
 

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Quote:
Originally posted by Kon
This is a digital signal, not analog. It either will work, or it wont. :)
Well, not entirely true. Yes it's a digital signal, however, this digital signal is special in that the clock used by the decoder is extracted from this digital bit stream.

If the cable introduces noise (bad cable), the clock extraction can be less than perfect, and can indeed alter the end result -- the sound. With S/PDIF it really is more than just it either will work, or it wont (sic).

FWIW, search for jitter.

I use homemade canare cables and they work great.


-anders.
 

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Discussion Starter · #12 ·
Thanks guys. It is great.


I see no answer to my second question yet.


What about sound quality from a HTPC versus a standalone player?


Anyone tried it on a expensive system.
 
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