How to solder to these round lugs?

Franko

Franko

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I need to replace the 3.5mm Jack on my headphones. I ordered this repair jack but I'm not sure how to go about soldering the wires to the cylindrical lugs. I guess just tin the wires and press them flat onto the lugs, but I fear enough heat will damage the plastic insulation around and isolating the lugs. Is there an official way to make this connection? the small lug is not hollow.

The lugs in question are marked with red arrows. I think I can handle the ground connection. I've repaired lots of stereo and mono jacks, but have not encountered lugs like these before.

headphone plug_1015.JPG
 
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I've done those and they can be tricky because of the melting problem. Use rosin cored solder of fairly small diameter. If you have a clip or pana-vise or third hand jig of some sort, that will make it easier to keep the wires in place while you apply just enough solder / heat. For something like this, I will usually put solder on the surface of the lugs and on the wire, then melt the two together. Be sure not to build up the solder too thick or the shell won't go back on. You can fan the copper wires flat if you have to. Also, don't forget to put the shell on the wire first (so you don't end up doing it twice). Good luck.
 
Find a spare jack, like on an extension cable or some piece of audio equip and plug the thing into it to hold it while soldering. It will act as a bit of a heat sink and keep the plug pieces lined up while soldering so even if the plastic gets a little soft while its warm, the pieces won't be able to move about. Let it cool before unplugging.
Joe
 
My method would be to use some good radio flux to get the cylindrical parts tinned first. If the solder wont "take", sometimes
a little burnishing will help to get the parts to tin. Once you have accomplished that, the soldering process will be a breeze.
I would flux the wires and tin them as well in order that the soldering goes quickly. A pencil tip iron would be my choice for
this kind of work along with using a bit of quality electronics grade solder. Joe's idea would certainly be helpful for this job.:encourage:
Thanks Joe!
 
Use an iron with enough mass at the tip to solder instantly, I use a 1/2lb copper iron for jobs where over heating could be a problem, heated with a blowlamp until the flame begins to show some green colour, gently scuffing surfaces to ensure they're absolutely clean and using a good lead/tin flux cored solder.
It's counter-intuitive but you need a minimum temperature to solder and as time is your enemy a big iron at the correct temperature will do this kind of thing best,
Regards,
Nick
 
Agree Burnish it , Tin you wire, Then min temp needed. , I would also heat the wire as you stick it in and as light a touch on the other as possible. Have done some like that, have also melted the insulation on some of the tips like that. Good luck.
 
Thanks to all for lots of good ideas. You guys are the greatest.

This is to repair a very good set of AKG headphones — worth the effort to repair.
This jack is very small, I can barely see the lugs. The wires I'm soldering to it are also tiny.
My close-up vision is departing. I think it is time I got one of those magnifying lamps.

I like the heat sink idea to maintain alignment, and will try it. I may try drilling a good fitting hole in a chunk of aluminum (if I have a bit that's a fit). Most of the female plugs don't apply even pressure on all sides, but press from one side.

Also tinning the lugs and the wires. Get the solder to stick to the lugs, then all I have to do when attaching the wires is melt a little of the solder and not heat up the whole lug. I have some very small 60/40 resin core solder.

cathead said:
My method would be to use some good radio flux to get the cylindrical parts tinned first. If the solder wont "take", sometimes
Joe!
Click to expand...

I've never heard of "Radio Flux." I looked for it but no results.
I did see 'no clean' soldering flux pens (and hypodermic applicators). Is that the same thing?
 
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Work fast, get in and out quick to avoid melting the plastic
The flux in the solder is probably enough/ 40 watt iron is fine you don't need a blowtorch
Mark
phase-plasma rifle in the 40 watt range?
"only what you see here pal"
 
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+1 on a larger iron and in and out quick. If the connection won't tin or the wire won't stick, pull away an let everything cool down before trying again. Good quality solder and flux make a big difference as well. Also, you can try heat sinking the other connections while you are soldering. A pair of needle nosed pliers clamped on with a rubber band will help. Bonus, if you mount them in a vise, you have a stable work area.
 
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