CAT5e Cable fun! Line level.

Pano

Administrator
Paid Member
2004-10-07 6:05 am
Panama
CAT5 as interconnects? You betcha! I'm happy.

Nothing magical at all, it just that they work were I didn't think they would, and they work well. Here's the story.

We have a music system at work to keep the night crew (me) happy and entertain the day crew. Just a pair of speakers and a vintage Sansui receiver + a CD/Cassette/Radio boom-box. Mostly the source has been streaming audio off the computer or music files on the computer. Simple stuff.

But we recently moved office and the computer is now a long way from the Sansui receiver. What to do? Had to run a long line level pair thru the ceiling. But I hated to buy expensive cable, so I went he cheap route.

At first I thought I'd use leftover telephone cable, but didn't have enough. So it was CAT5 instead. But 40 feet of unshielded cable? Even if it is twisted pair? Ouch!

So I pulled it and put RCA connectors on one end. (Orange and Green pairs). Connected it to the Sansui inputs and HUUUUMMMMM........ A nice loud 60 cycles. But - no buzz, no rizz, no hiss. Just heavy 60 Hz. OK, might as well try to run signal.

Put the 1/8" mini plug on the other end and plugged it into the back of the MAC G5. Presto! No more hum. No noise at all. And the audio signal from iTunes was loud and clear.

None of what I feared came to pass. No buzz, no hum, no hiss, no apparent hi-end loss, no massive cross-talk, no big signal loss.
And more than half this cable is running thu parts of the ceiling with power lines, fluorescent lights, Ethernet cables, cable TV, telephone, thermostat and alarm wires.

Have to say - I'm happy. :D No need for expensive cables here. Still quite surprised at how well it works. Cheap, too!
 
I tried using a twisted pair pulled from cat5 cable for a phono line for my dads turntable (cable from the turntable to the preamp). I found that it picked up loads of hum from the adjacent power cables, so I switched to some fairly cheap two core shielded cable and the hum was no more.

For line level signals it might be fine, but a shield can reduce noise much further still.
 

Pano

Administrator
Paid Member
2004-10-07 6:05 am
Panama
DcibeL said:
For line level signals it might be fine, but a shield can reduce noise much further still.

Yeah, I'll bet for a phono pickup it was a disaster! Wouldn't do well for mic cable, either. Still very surpised at how well it works at line level, at least in this case.

(hmmm come to think of it, I used to use litz wire on my tonearm - no shield there)


EWorkshop1708 said:
I like to cut them up and use the little wires as jumpers and connections when making my own circuit boards.

Great for that use, too. Cheap and plentiful. :)