Anyone know anything about TOSLINK cables (S/PDIF optical)?

[iamsostupid]

These are pretty expensive cables, but that's not really why I'm posting. They seem to hold paramount the specification of signal-to-noise ratio, but I have to wonder, since most places only sell 1, 2, and 3 -meter cables, can the signal loss over distance be that great? I wish to soon connect my computer to a Dolby 5.1 receiver via a TOSLINK cable, and I'll need about 10 meters to connect the two devices (I have a Hercules Game Theater XP 7.1, if any of you know about that). That means I'll have to buy two 5-meter cables and a coupler. Does anyone know if this will degrade my signal at all? I really don't know much about the S/PDIF audio specification so if someone could shed some light about signal loss I'd be very appreciative.

[Dalhectar]

Someone at AVS Forum would most likely know the answer to that question. Since it's optical, I wouldn't think there would be ANY loss in quality over transmission, but I could be wrong.

[SkyDog]

If you're in the U.S., you can order longer TOSLINK cables by calling the people from this site.

The problem with longer lengths is that the optical receiver circuitry needs a certain level of light in order to work. As optical cables get longer, the amount of light that makes it from one end to the other decreases. Some manufacturers specify 3 meters as the maximum cable length, but much longer cables often work just fine. Usually, they're just trying to cover their @$$ in case you buy crappy long cables that attenuate a lot of light. Speaking of light attenuation, I'd suggest you avoid using couplers if at all possible since even a good coupler loses some signal strength.

But so long as there's enough light getting through the optical cable so that the receiver gets a signal, you lose NO quality due to signal loss over distance. Analog signals are susceptible to degradation via signal loss and interference, but digital signals like the one over your optical cable are just 1's and 0's. So long as the receiver gets all those 1's and 0's at the other end of the cable, it can perfectly recreate the input signal.

[Adisharr]

In looking at many of the input / output circuits of digital audio systems, they all seem to use the same output circuit to drive/receive the coaxial and optical I/O. I don't see why one would be better than the other assumming both have the minimum signal needed.