# Koss PortaPro repair



## JoeWalsh

I've got two pairs of Koss PortaPros, both of which have broken at the plug. Unfortunately, I went and tried to fix them myself instead of using the warranty I wasn't aware of. I can't solder something that lasts more than a week or two.

 How on earth do I get the paint isolation cleanly off of the wires (of all the things to use for isolation)? I've been trying to burn it off using a lighter with less-than-satisfactory results. I also have shaky hands which make getting a reliable solder at the plug a pain. Would it be easier to get a nice big plug with well-spaced solder terminals or get some cable with a plug already attached?
   
  I'm mad at myself for missing the warranty info...
   
  Any help greatly appreciated.


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## Simon C

youre better off just replacing the entire cable, theyre really quite easy to take apart.


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## JoeWalsh

So now I'm trying to get the black cover separated from the blue housing. I looked at a few threads on disassembling PortaPros and tried using a flathead and knife to pry at the four tabs in the back. It hasn't budged, and stress marks are appearing on the blue housing from where I've been prying. How much force does it take to get these off (this is how to get them off, right)?


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## Simon C

the drivers should just pop off their swivel on the headband with your fingers, then you just remove the little plastic covers over where the wire goes in. 
   
  see? 

   
  you dont need to take the driver out of the blue housing at all. 
   
  see here for the wiring http://www.head-fi.org/t/71148/diy-cable-gallery/6690#post_7494218


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## JoeWalsh

Oh...now I feel stupid 
	

	
	
		
		

		
			




  That picture was exactly what I needed.
   
  As long as I'm doing this, are there any cheap cables or earpads that are recommended over whatever I have (stock earpads) or the generic cables I can find at Fry's or RadioShack? I don't want to spend more than maybe $20 on either option and I know that won't go far, especially with cables.


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## Simon C

pick up 6 ft of this (or as many feet as you want your cable to be)
  http://www.redco.com/shopexd.asp?id=1149
   
  one of these 
  http://www.redco.com/shopexd.asp?id=305
   
  and a little of this in your choice of color
  http://www.redco.com/shopexd.asp?id=418
   
   
   
  strip the outer jacket off of about 10-12" of the wire, clip the bare copper shielding at the base of the cut (wont be needing it), and make two twisted pairs out of the 4 wires. black/red, and blue/clear. 
   
  heat shrink over where you cut the jacket, where the two twisted pairs split off. 
   
  at the other end of the cable, strip off an inch or so of the jacket, and twist the black and clear wires together. those will be joined and soldered together as your ground. the blue wire will be your left channel, and the red will be the right channel. 
   
   
  slip the barrel of the neutrik connector over the wire , followed by about an inch of your heat shrink, and then the plastic insulator they include with the neutriks. solder and crimp the neutrik connector on, slide the plastic insulator over the connections, slide the heat shrink down until it just covers the crimp on the connector, shrink it with a lighter or heat gun (careful not to melt it), and then slide the neutrik barrel over it all and screw it on. 
   
  there, you have now finished most of the cable. 
   
  soldering it to the drivers is pretty simple and straightforward, you can figure that out.


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## JoeWalsh

Sounds good - I'll order some.


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## Simon C

if you need soldering tips/advice and whatnot, theres plenty of it out there. google is your friend.


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## LizardKing1

Simon what's the difference between the mogami w2799 and the w2893? It's just that I see the w2893 recommended more often.


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## Simon C

w2893 is decently thicker.


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## LizardKing1

But still not as thick as w2534 right?


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## daman

I have soldered a new plug to the PortaPro wire. I scratched away the coating of the wire strands using a knife. After that it is easy to solder. Just don't scratch too much or the strand will break.
   
  Here is a picture of it:
http://plazma.kapsi.fi/pictures/temp/slim_plug.jpg
  I needed a low profile plug for a mp3 player with a socked on the side. I soldered it and added some epoxy for protection.


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## LizardKing1

That looks like you covered the entire thing in solder.
   
  daman... Did you cover the entire thing in solder? 
	

	
	
		
		

		
		
	


	



   
  Seriously now, I'm not complaining about your work, it must have been really meticulous to use such a small plug. So you used silver epoxy? By the way, next time try to clean the cover of the wire by passing the solder wire through it. I also assume the plug on the right is the old one, right?


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## Simon C

Quote: 





joewalsh said:


> Sounds good - I'll order some.


 


  Take pics of your process and the final product and post em up here!


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## drtturnip

For the cloth type wire tin the end using a combination of heat and solder until the coating breaks down and the solder sticks.


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## daman

Quote: 





lizardking1 said:


> That looks like you covered the entire thing in solder.
> 
> daman... Did you cover the entire thing in solder?
> 
> ...


 
  The connector is covered with clear epoxy. It has lasted well for 3 years already. I don't know why you think it's covered in solder or silver epoxy???
   
  Some headphone wires got a coating that won't burn away easily. It just causes the strands to heat up and then melts the insulation. Then you need to scratch away the coating just like I did. Some cables got a weaker coating on the strands that you can easily burn away with a blob of solder on the soldering iron.


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## JoeWalsh

Got my materials yesterday. Now to find some spare time...

 I'll put up process pics when I finish.


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## Simon C

Keep us updated.


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## JoeWalsh

Here's what I've done so far. The heatshrink was too large, so I used what was lying around (which happened to be 4" long 1/4" black sections and 12" clear sections, which lets you see the wires 
	

	
	
		
		

		
		
	


	




). My question is: should I use some kind of insulation to solidify the solder area (fill it with epoxy or something)?


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## LizardKing1

I like to cover the solder joints on connectors with heatshrink. You can use epoxy or hot glue as well, since the main goal is to give stability to the joint and isolate the different conductors.


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## JoeWalsh

They live!
   

   
  The clear heatshrink sections were a bit short, so I used electrical tape to cover the remaining inches. I didn't reinforce the plug yet since it seems relatively sturdy - I plan to if I encounter problems. Many thanks for the help!


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## HPuser9083

Since the drivers can be popped off with no damage at all, I may try placing them in my UR40 chassis and see how they sound, and get some KSC75s to put in the Portas' headband if successful.


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