electronicsgeekfilter

August 28, 2005 7:09 PM

I need to solder on a new plug for the cable of my stereo headphones. They are not hard-wired; the headphone end has a stereo plug the same size as you'd use for a cell phone. The other end, now that I've clipped off the offending (molded-on) plug, has three colored wires -- red, green, copper. Which colors are left, right and ground when I do the soldering?
posted by banjomensch to Technology (8 answers total)

here's a lovely illustration to assist you
posted by freq at 7:30 PM on August 28, 2005

The unsheathed copper wire will be the ground. You're probably best off testing which is left and right, but if I had to go out on a limb I'd guess the red wire was the right one.
posted by fvw at 7:37 PM on August 28, 2005

Ground will be the unshielded wire, which is usually wrapping the other two wires. I've always used red=right and black or green = left, and I've yet to be wrong.
posted by fake at 7:56 PM on August 28, 2005

Red right. Always red right.

And when there's a black cable, black=ground. Always. Just one of those universally accepted electrical engineering agreements.
posted by Civil_Disobedient at 9:23 PM on August 28, 2005

And when there's a black cable, black=ground. Always. Just one of those universally accepted electrical engineering agreements.

Also, just to clarify, while in this case red is "right". Universally speaking, red is always "ring" and green is always "tip". This is true of power adapters, telephone connectors, etc.
posted by o0o0o at 10:33 PM on August 28, 2005

When I do this sort of thing, I cut off the old plug with some of the cable still attached. Then I can check continuity from the wires in the cable to contact-surfaces on the plug, and correlate with the new plug. (Assuming that not all the conductors in the old plug are broken.)
posted by Kirth Gerson at 4:10 AM on August 29, 2005

Then I can check continuity from the wires in the cable to contact-surfaces on the plug

This is definately the best method, particularly when hooking up a speaker--just because something's labeled +/- doesn't necessarily make it so, and a single reversal can mean improper phasing. It's worth it to spend $20 and take a couple of minutes to learn how to use a voltage meter. With headphones this isn't much of an issue, since the ground is often wrapped over the signal leads.
posted by Civil_Disobedient at 6:44 AM on August 29, 2005

And when there's a black cable, black=ground. Always. Just one of those universally accepted electrical engineering agreements.

This doesn't apply to home electrical wiring, where Black is HOT, White is Not, and Green is ground.
Don't get yourself dead playing with those 3 wires next week.
posted by whoda at 6:45 AM on August 29, 2005