document updated 15 years ago, on May 17, 2008
Looking for information on UTP interconnects (not those silly speaker cables) for transmitting audio for 50+ feet..
- Most commercial solutions use a balun at each end.
- So, my question is, when are the baluns necessary, and when are they not? (20' audio cables don't need baluns...) There's several questions, I think:
- Do we need to take care of termination?
- Do we need to do impedance matching?
- What about the balanced/unbalanced thing? Do you have to run audio over UTP as balanced, or can it be unbalanced?
- Why does balanced audio use three pins, when balanced digital (cat5, usb? (though it does carry a ground, though not for signalling purposes?)) only uses two? What's the point of the third (ground) line?
- Can you just run unbalanced audio over cat5? (answer = no, depending on distance?)
- I'm still confused. I thought the whole point of having two connectors on an audio connector was because they were received as a differential signal. In some cases, you have to add a single transformer in order to break a ground loop. I guess that means they're not received differentially?
- That's not hard to test. Connect only one line at a time between signal source and an amplifier, and see if it can work with either one line, or the other.
- why does an audio balun cost $40+, when network cards contain several of them, and cost $10?