[Kibble Fat]

Hi,

After about 8 months of use, the strain releif on my NuForce NE-7Ms broke so the cable is taking all of the abuse. I've decided to reterminate them and I've hit a small snag. I carefully stripped the outer insulation to reveal 4 wires (28awg or something). It appears that each of the 4 wires is twisted around a non-conductive cloth/nylon.

One of the wires (I assume that it is the ground) has its own white insulation (copper inside)
Another appears to be bare copper
The last two look like they're anodized red and blue (maybe copper?)

Anyways, the problem is that I can't get my multimeter to read anything from the section i stripped to the plug conductors. I want to swap the 4 conductor plug that came with it for a Neutrik mini (3 conductor). The headphones were working just fine before I did any work on them.

Is my multimeter not sensitive enough? I thought it could at least read some resistance...? ($25 craftsman: http://www.craftsman.com/shc/s/p_101...lectrical+Shop)

Any help/advice would be greatly appreciated

Eric

 

[Kibble Fat]

UPDATE:

Ok, so I tried touching the test leads to the very end of the strands and I can get some signal. This leads me to believe there is some sort of coating on all of the wires which changes my question to be: how do I get this coating off?

Here's what I came up with: (conductor order convention)
tip, 1, 2, 3

copper2
red 1
blue tip
white 3

So I should just drop the mic signal? Is this the generally accepted 4-cond configuration?

 

[jnewman]

The "bare" wires have an enamel insulation coating. The normal way to get the coating off is to dip the ends of the wires in a pot of solder. You can get by by just putting a blob of solder on it and holding the iron on until the coating bubbles off. You can also get chemicals that will strip the coating. Some people scrape it off with a razor blade or use very fine sandpaper, but you can damage the wire that way and you've only got so much you can use.

I can't help you on which wire is which, but you should be able to do better with your multimeter after you get the coating off.

 

[Kibble Fat]

cool thanks! I'll let you know when I get stuck again haha

 

[Kibble Fat]

UPDATE:

tip, 1, 2, 3
copper...............2
red....................1
blue..................tip
white.................3
white shield.........2

Now I'm thinking that white is the mic (with its own ground[2]) and copper is the ground[2] for the others which doesn't match the pic i posted above. hmmm
(now THIS)

Any suggestions on chemical strippers?

 

[Kibble Fat]

no one?

 

[jnewman]

It looks like you have it right, but I can't promise anything.

Given the recent vintage of your 'phones, you can PROBABLY just solder the enameled wires directly and get a good electrical connection. A lot of modern enameled wires are "self fluxing," i.e., you can just solder them and it works. I've never used any of the chemical strip agents, so I can't help you on that one.

 

[Kibble Fat]

Ok, so I ended up trying to strip it with acetone without any visible progress. It still completely repelled any solder I tried to tin it with. I then bombarded the wires with solder (about 20 secs each, off & on) and it stuck. I don't know about the self-fluxing. It looked more like I was burning the coating off. Once I got the plug soldered up, I tested it on my lil bro's $20 player and it worked! Unfortunately, I forgot the plug jacket LOL! That's ok, I needed to shorten it up more anyway.

For future reference, the NE-7Ms use the copper for ground, blue for left, and red for right. The shielded white is for the mic which I cut short.