“I’m wondering about glass fiber optic cable. I’ve heard it’s more reliable than “standard” plastic fiber optic cable, but is it interchangeable?”
One of the main advantages of the real glass stuff over the plastic optical cables we normally use in audio is that the glass maintains the integrity of the signal (the light in this case) better. This is a broad generalization, as there are a number of different types and grades of glass cable, but in general it all performs better than the plastic. It also costs a LOT more. To date there has been no compelling reason to use glass fiber optic cables in typical audio applications because the plastic stuff we use is more than capable of doing everything we need it to do just fine. The only issue we run into at all are the length limitations. These vary depending upon what you’re doing, but you’re not likely to find an ADAT optical cable made of plastic that’s more than 30 feet long, for example. Since there are very few audio applications where glass cable is required, it’s almost unheard of as a product in audio circles. The cable itself is perfectly interchangeable in concept, but you’re not likely to find a typical TOSLink cable made of glass at the local hi-fi store. Move over to the telecommunications industry, however, and it’s a whole different ballgame. Unless you have an application where you need to run digital audio long distances, we’d say the plastic cables everyone sells are just fine.