Friday, 11 December 2015

Koss Porta Pro cable replacement guide

My second pair of headphones, the Koss Porta Pro, has served me well the last couple of years and I am surprised at how well they have withstood all the abuse they have been put through. I used them when I was sanding the Oy cabinets. I had them with me on my trip around the world, carelessly packed in my backpack or pockets. They have been with me on over a hundred workout in the gym and then afterwards just tucked in my gym bag along with other items. The frame is still perfectly straight. The foam earpads are looking pretty ok, just a few holes on the edges. The cable has been the part that has handled the abuse the worst. About half a year ago it turned really stiff so it wasn't a very good idea to fold the headphones and then wrap the cable around them. I did that anyways though and eventually the outer insulation snapped in half and it was only being held together by the really thin wires. I solved this temporarily by using some electrical tape. It didn't last very well though and I had to change the tape every two weeks or so. I ordered a 3.5mm -> 2xRCA cable that I was planning to use as a replacement. However, that cable got put in use elsewhere (between the O2+ODAC and my stereo amplifier) so I kept on using the electrical tape. Last week when I was about to go for a walk the sound just died in one side. One of the wires had broken. I managed to fix this with some soldering and lots of electrical tape, a really ugly short term solution. Meanwhile I had ordered a replacement cable from Ebay.

Short term electrical tape solution.
The replacement cable arrived today and I just couldn't wait with replacing the old cable. I found this guide over at iFixit which shows how to disassemble the headphones but also how to do if you have a non-standard replacement cable, similar to what I was planning to do in the beginning.

I decided to write my own guide for you, based on if you have the same cable as I have. I bought this cable from tuttoit on ebay. It is cheap, shipping included and it looks ok. I have no idea about the durability yet but I will come back later to comment on that. As usual it took quite a while for it to arrive but that can be expected when ordering things from Asia with free shipping.

As the iFixit guide mentioned above says you need to start by removing the speakers from the frame. You do this by gently pulling them apart. With a bit of force they will snap off from the frame.

Then you should remove the black foam. It just hangs onto small plastic pins running around the edge on the backside. Gently lift it off the pins and remove it.

Now is also a good time to make sure there is no dirt or hair behind the black cover. That could potentially degrade the sound. If you have had the headphones for a while there will probably be some stuff there. Gently remove it and be careful not to touch the speaker drivers.

The next step is to remove the plastic cover covering the wire. For this you need something pointy, like a flat head screwdriver, knife or similar. Bend gently and it will start coming off.

Take note of how the cables are soldered. Take a picture with your phone or write it down on a piece of paper.

Begin with desoldering the wires to one speaker. Don't do both at the same time. I would recommend trying to be as quick as possible when heating up the joint and removing the cable. The plastic can deform or even melt if you keep the heat on for too long.

New cable soldered to the connector.
As you can see in the picture above I kept the heat for a little too long so the plastic deformed a bit around the hole where the pin on the cover goes. This turned out to be a little problematic since the cover didn't want to come back on again. I had to scrape some plastic out from the hole to make it a little bit bigger.

The last step is to wrap the cable around the pins. This way it is protected in case you would pull on the cable. Put the cover back on and then put the foam pads back on. By this time you have probably forgotten which is right and which is left, but don't worry. It doesn't really matter, just run some stereo channel test track and you can easily figure it out. I used this track on YouTube. Then just push the speakers back in place on the frame you are done.

Hopefully this will allow me to use these fantastic headphones for another year or two. Sure, they are no hifi headphones but considering how cheap and portable they are amazing. Perfect for when you are out taking a walk, running, or training in the gym. Heck, I actually think they sound better than most other headphones that I have listened to it the same price range.

Estimated time: 10 minutes
Estimated cost: ~40SEK / ~$4.5 / ~€4 / ~£3
Difficulty: Basic
Tools needed: Soldering iron, flat head screwdriver or other pointy object