K1000 Recable Guide

[Fitz]

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.

[derekbmn]

Nice work and photos! Have you thought about eliminating the PCB and run them without it?

[HeadphoneAddict]

Great post!

I of course will not attempt this myself, as I will FUBAR the driver for sure. I was considering getting Alex at APS to re-cable mine for me after I get tired of them stock. Do you have any other recommended brand cable for the K1000 that people have reported does well (other than SAA Equinox)?

[luvdunhill]

Does the PCB contain a protection Zobel of sorts?

[Fungi]

Great post!

I of course will not attempt this myself, as I will FUBAR the driver for sure. I was considering getting Alex at APS to re-cable mine for me after I get tired of them stock. Do you have any other recommended brand cable for the K1000 that people have reported does well (other than SAA Equinox)?

BlackClover

[Fitz]

Nice work and photos! Have you thought about eliminating the PCB and run them without it?

Does the PCB contain a protection Zobel of sorts?

I'm not entirely sure what the purpose of the PCB is, as I still haven't gotten around to examining it. I wouldn't want to remove it until I fully understand its function and any effects on the sound, as I'm sure AKG put it there for a reason.

Great post!

I of course will not attempt this myself, as I will FUBAR the driver for sure. I was considering getting Alex at APS to re-cable mine for me after I get tired of them stock. Do you have any other recommended brand cable for the K1000 that people have reported does well (other than SAA Equinox)?

Well, I've gotten excellent results using my own Black Clover cable. I don't usually make a habit of recommending competitors' cables.

[derekbmn]

I'm not entirely sure what the purpose of the PCB is, as I still haven't gotten around to examining it. I wouldn't want to remove it until I fully understand its function and any effects on the sound, as I'm sure AKG put it there for a reason.

I have always understood it to be nothing more than a notch filter. Most that have had it done to theirs seem to prefer it without.

My pair had it done before I bought them, so I can't comment on any before and after changes.

I do know that I would like to get a pair with them in and preferably an earlier serial #.

[Fitz]

I have always understood it to be nothing more than a notch filter. Most that have had it done to theirs seem to prefer it without.

My pair had it done before I bought them so I can't comment on any before and after changes.

I do know that I would like to get a pair with it in and preferably an earlier serial #.

But just "notch filter" doesn't tell you frequency, bandwidth, or gain. With how finicky the K1000 is to position, I wouldn't want to go chasing after shadows trying to say whether the change is positive or negative. It's much easier to decide when I know exactly what the difference I'm listening for is.

[jp11801]

My understanding is the notch filter is to reduce the 2k frequency, this info came from the guy that rewired my pair

[Fitz]

If it's working anywhere near 2kHz, then I'll definitely want to figure out it's exact parameters before even considering removing it.

[Duggeh]

Excellent guide sir. Bravo.

[swt61]

This is a superb guide to recabling the K1000. I almost feel like I could take on the task myself.

I'm not that brave yet, but it's an excellent guide if I ever do decide to do it or have it done.

[nikongod]

My K1000 had the PCB "spontaneously removed" while recabling.

If you would like to borrow them to compare you are welcome.

[Fitz]

Thanks for the offer Ari. I'm probably not going to worry about the PCBs for now, as I doubt I'll have the time or motivation to do any extensive comparisons in the near future.

[inukage]

Thanks for the great guide!

I have flirted with and then been turned away from the idea of attempting a recable job myself on my d2000s a few times already. This guide makes me want to try again.

[deepak]

Hehe the only thing the D2000 has in common with the K1000 is they both have a place to solder the wires.

[Duggeh]

Inspired by Fitz I opened up my K1000 for a look-see.

The insides are not quite the same, as you can see. That very fine wire bridging the posts is odd. Theres also no solder joining the posts to the PCB. The solder points are further apart. Thisll make heating and removing both much trickier.

Edited April 25, 2009 by Duggeh

[Jon L]

The insides are not quite the same, as you can see. That very fine wire bridging the posts is odd. Theres also no solder joining the posts to the PCB. The solder points are further apart. Thisll make heating and removing both much trickier.

My K1000 looked like your with the fine wire, etc. My serial numbers were >10,000; what are you guys' serial numbers like?

[HeadphoneAddict]

Mine are #1478 so might be more like Fitz's

[Duggeh]

#11150

I also had to remove the back grille in order to get the front one off (because there was a fair amount of glue holding it on.

Putting it back together was 8/10 on the tricky scale, where replacing omega2 pads is a 6.

[Looser101]

#11150

I also had to remove the back grille in order to get the front one off (because there was a fair amount of glue holding it on.

Putting it back together was 8/10 on the tricky scale, where replacing omega2 pads is a 6.

#11172

...and it looks like yours. The pins are J shaped and go through to the plastic frame and then back up. One end goes to the driver wires, the other to the PCB. I decided to wait to rewire mine.

[swt61]

#06713

Can't tell through the grill what my pin configuration is.

Edit: Actually looking a bit closer they appear to be as Fitz'.

Edited April 26, 2009 by swt61

[Fitz]

My pair the guide is based on is serial #03796. A 2nd pair I just bought is serial #10585, so hopefully when I get it it turns out to have this other PCB so I can revise the guide to account for both. If it has a significant amount of glue I'll see if I can update the guide for more detail on that as well, or perhaps make a section for full grille reassembly regardless...

The fine wire on your pair Duggeh is the voice coil wires. The posts are looping back up to the front instead of to the back like on mine, and there are two fine copper wires twisted in with that white bit (string?), which is likely used to give the wires some amount of reenforcement to protect from damage.

[stevieo]

superb post. thanks.

[flecom]

Inspired by Fitz I opened up my K1000 for a look-see.

http://www.thismanwillkillyou.com/bunf/Head-Case/K1000/Cimg1840-1024.jpg

The insides are not quite the same, as you can see. That very fine wire bridging the posts is odd. Theres also no solder joining the posts to the PCB. The solder points are further apart. Thisll make heating and removing both much trickier.

every pair i have recabled has looked like this... never seen that other type of PCB...

the only thing i can offer is try and leave the iron on for as little time as possible when your removing the PCB... remember those metal pins are set in plastic, so heating them too long will cause them to move around