Fitz
Headphoneus Supremus
- Joined
- Nov 12, 2005
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I've seen posts here and there commenting on the difficulty of recabling the K1000, and it's definitely not something a novice DIYer should attempt, but I think most of the fear and confusion over recabling them comes from their unusual construction and lack of information regarding safe disassembly. I hope this guide will help clear up the process for advanced DIYers who are already comfortable recabling normal headphones, but wary about working on the K1000.
A few notes before I begin...
You should have your cable already built and ready to go before starting disassembly, so the K1000 is not left in a partially disassembled state, and complete the work on one earspeaker before disassembling the next one. Unless you intend to modify the enclosure, the wires and any heatshrink or sleeving must be as small as the stock cable. And finally, if you have any doubts at all about your ability to successfully complete the recable, do not attempt the recable. You definitely do not want to find out the hard way whether or not it's beyond your current skill level.
Now then, to start disassembly, you need to remove the bottom plastic cover off the earspeakers. One screw is visible out in the open, and the other is hidden underneath the rubber strain relief.
With the screws out, the piece will slide easily down the cable away from the earspeaker, giving you access to removing the ring that holds the grilles on. It's snapped down over two pins, and to remove it you will need to lift it up off these pins.
With each side free of the pin, let it move outwards so it is just loosely sitting on the earspeaker frame. If the grilles have never been removed before and the adhesive is still holding strong, you may have to work it loose manually. Don't worry about the rear grille at all, just get the retaining ring and front grille loose.
When everything is loose, remove the front grille and set it to the side, so you have full access to the front of the earspeaker.
Go ahead and resecure the ring to hold the rear grille in place. This is a lot easier than taking the grilles completely off and trying to put them back on later, and keeps the back of the driver protected while you're working on the front. Once you get it snapped back in place, remove the two screws that hold the PCB down.
This is where it gets interesting. With the screws out, the PCB is still held in place by the metal posts that connect it to the driver. The problem is these posts are soldered to the PCB. There are different ways to desolder the posts and remove the PCB, but this is the one I find to be the safest and easiest as long as you have somewhat steady hands. It's a two-handed procedure, and you'll be soldering millimeters from part of the driver, so make sure you have all your actions thought-out before doing it.
You will need to heat both solder joints at the same time with the iron (not necessarily as I'm holding it in the picture, use whatever angle and technique you're most comfortable with as long as you stay clear of the diaphragm), while gripping the coil and using it to pull the PCB up and away. The side of the PCB towards the driver is notched out, so you don't have to come straight up the whole way. Instead, you can come up a little to clear the enclosure, then forward towards you. Do not leave heat the posts for more than a few seconds. If you find you can't heat both up to the melting point quickly enough, either raise the heat on an adjustable iron or use a hotter iron. If you can't do either, then you should abandon the recable attempt and reassemble the earspeaker, because excessive heating at these joints could cause damage to the driver.
If you successfully removed the PCB, then while everything is still heated up clean up the pads on the PCB and the solder posts of any excess solder. You want the notches on the PCB completely visible and the posts free of any solder blobs. Be very careful about the driver if you do have to run your iron across the metal posts to remove some excess solder.
On the back side of the PCB, you can see where the cable solders to it. Before removing the old cable, make note of the polarity on how the stock cable is soldered down in case there are any variances on the PCBs and yours doesn't have the same polarity as mine. When you remove the stock cable and solder the new one on, be sure to remember to transfer the bottom cover / strain relief to the new cable.
Also make note of the channel the cable has to fit into behind the PCB, as it has a couple protrusions that you must fit it around, otherwise the PCB will pinch the cable against the enclosure. It can be a little awkward getting the cable to fit right and the PCB set back in place, but once you do get it back in, immediately screw it down so it doesn't pop back out and force you to start over.
Now you're almost done, and it becomes clear why the excess solder was removed from the posts and PCB earlier. The posts have to be resoldered to the PCB, and I recommend heating the PCB first and adding a bit of solder to replace what you removed earlier, and then heating the posts to make the solder joint. Just serves to further minimize any potential risks caused by excessive heat.
Once both posts are soldered back down, you'll want to test that side before reassembling it. If your music or test tone comes out, then you're good to go, and can reattach the front grille the same way as it came off, and screw the bottom cover back down. If for any reason you don't get any sound out of that channel, take a short break to avoid any further mistakes caused by frustration. After the break (I strongly advise against skipping it), double check there isn't any problem upstream by plugging another pair of headphones into the amp (or however you're getting a test signal to them), then use the spots to the top right of the PCB to check for continuity from the end of the cable to the PCB. The problem most likely will be found by checking these two things, as your drivers should be fine if you followed the guide carefully.
And with one earspeaker completed, you can repeat the entire process on the other one, which should be much easier than the first one. Perhaps you'll feel much more confident about the process and won't even need to look at the guide the second time around. Either way, once the second one is done, you can sit back and enjoy your newly recabled K1000s, with the satisfaction of having done the task yourself.
A few notes before I begin...
You should have your cable already built and ready to go before starting disassembly, so the K1000 is not left in a partially disassembled state, and complete the work on one earspeaker before disassembling the next one. Unless you intend to modify the enclosure, the wires and any heatshrink or sleeving must be as small as the stock cable. And finally, if you have any doubts at all about your ability to successfully complete the recable, do not attempt the recable. You definitely do not want to find out the hard way whether or not it's beyond your current skill level.
Now then, to start disassembly, you need to remove the bottom plastic cover off the earspeakers. One screw is visible out in the open, and the other is hidden underneath the rubber strain relief.
With the screws out, the piece will slide easily down the cable away from the earspeaker, giving you access to removing the ring that holds the grilles on. It's snapped down over two pins, and to remove it you will need to lift it up off these pins.
With each side free of the pin, let it move outwards so it is just loosely sitting on the earspeaker frame. If the grilles have never been removed before and the adhesive is still holding strong, you may have to work it loose manually. Don't worry about the rear grille at all, just get the retaining ring and front grille loose.
When everything is loose, remove the front grille and set it to the side, so you have full access to the front of the earspeaker.
Go ahead and resecure the ring to hold the rear grille in place. This is a lot easier than taking the grilles completely off and trying to put them back on later, and keeps the back of the driver protected while you're working on the front. Once you get it snapped back in place, remove the two screws that hold the PCB down.
This is where it gets interesting. With the screws out, the PCB is still held in place by the metal posts that connect it to the driver. The problem is these posts are soldered to the PCB. There are different ways to desolder the posts and remove the PCB, but this is the one I find to be the safest and easiest as long as you have somewhat steady hands. It's a two-handed procedure, and you'll be soldering millimeters from part of the driver, so make sure you have all your actions thought-out before doing it.
You will need to heat both solder joints at the same time with the iron (not necessarily as I'm holding it in the picture, use whatever angle and technique you're most comfortable with as long as you stay clear of the diaphragm), while gripping the coil and using it to pull the PCB up and away. The side of the PCB towards the driver is notched out, so you don't have to come straight up the whole way. Instead, you can come up a little to clear the enclosure, then forward towards you. Do not leave heat the posts for more than a few seconds. If you find you can't heat both up to the melting point quickly enough, either raise the heat on an adjustable iron or use a hotter iron. If you can't do either, then you should abandon the recable attempt and reassemble the earspeaker, because excessive heating at these joints could cause damage to the driver.
If you successfully removed the PCB, then while everything is still heated up clean up the pads on the PCB and the solder posts of any excess solder. You want the notches on the PCB completely visible and the posts free of any solder blobs. Be very careful about the driver if you do have to run your iron across the metal posts to remove some excess solder.
On the back side of the PCB, you can see where the cable solders to it. Before removing the old cable, make note of the polarity on how the stock cable is soldered down in case there are any variances on the PCBs and yours doesn't have the same polarity as mine. When you remove the stock cable and solder the new one on, be sure to remember to transfer the bottom cover / strain relief to the new cable.
Also make note of the channel the cable has to fit into behind the PCB, as it has a couple protrusions that you must fit it around, otherwise the PCB will pinch the cable against the enclosure. It can be a little awkward getting the cable to fit right and the PCB set back in place, but once you do get it back in, immediately screw it down so it doesn't pop back out and force you to start over.
Now you're almost done, and it becomes clear why the excess solder was removed from the posts and PCB earlier. The posts have to be resoldered to the PCB, and I recommend heating the PCB first and adding a bit of solder to replace what you removed earlier, and then heating the posts to make the solder joint. Just serves to further minimize any potential risks caused by excessive heat.
Once both posts are soldered back down, you'll want to test that side before reassembling it. If your music or test tone comes out, then you're good to go, and can reattach the front grille the same way as it came off, and screw the bottom cover back down. If for any reason you don't get any sound out of that channel, take a short break to avoid any further mistakes caused by frustration. After the break (I strongly advise against skipping it), double check there isn't any problem upstream by plugging another pair of headphones into the amp (or however you're getting a test signal to them), then use the spots to the top right of the PCB to check for continuity from the end of the cable to the PCB. The problem most likely will be found by checking these two things, as your drivers should be fine if you followed the guide carefully.
And with one earspeaker completed, you can repeat the entire process on the other one, which should be much easier than the first one. Perhaps you'll feel much more confident about the process and won't even need to look at the guide the second time around. Either way, once the second one is done, you can sit back and enjoy your newly recabled K1000s, with the satisfaction of having done the task yourself.
