Denon/Fostex/E-MU Headphone Removable Cable Mod 3.5mm Jack Adapter

Summary:

I designed this mod since I wanted to be able to replace the cable on my Denon D2000 and D5000 but didn't want to permanently modify the frame, baffle or driver. This would allow me to go back to the stock cable is so desired.

The included STL files are designed to fit a front-mount 3.5mm jack like this one or this one. I threaded mine right into the raw plastic and it holds it quite well, no glue required. I've also included a OBJ file that doesn't have a hole cut for the jack so you can cut your own hole if you are using a different jack. However, keep in mind, because of the way it mounts to the frame it will either need to be a front mount jack or be held in with glue for it to work.

WARNING: DO THIS AT YOUR OWN RISK. I AM NOT RESPONSIBLE FOR ANY DAMAGE CAUSED WHILE DOING THIS MOD. MODDING A HEADPHONE CAN RUIN IT. ONLY ATTEMPT IF YOU ARE CONFIDENT IN SOLDERING/DE-SOLDERING ON A SMALL SCALE AND MODDING.

Guidelines:

1. Print a left and right jack adapter. I used regular PLA.
2. Disassemble the headphone cups completely, so the driver is separated from the frame.
3. Use a multi-meter to test which wire and soldering pad is used for ground and which is used for the signal. Make a note or diagram of the result.
4. De-solder the stock cable from the driver. NOTE: When de-soldering make sure to have your iron hot enough that the cables can be quickly removed from the driver (1-2 seconds max). IF YOU EXPOSE THE DRIVER SOLDERING POINTS TO TOO MUCH HEAT FOR TOO LONG IT CAN DE-SOLDER THE VOICE COIL AND IT WILL RUIN THE DRIVER! 
5. Thread the stock cable out of the hole.
6. Remove the rubber cable strain relief from the hole (should be pushed inside to remove it).
7. Solder new wires to the new 3.5mm jack. Make sure they are long enough to reach the driver comfortably once mounted and are designated which is ground and which is the signal. NOTE: You should wire the jack to match the cable you wish to use with your headphones since not all dual 3.5mm headphones cables are wired the same way.
8. Use heat shrink, electrical tape, or hot glue on the wires so the exposed tabs at the end of the jack are completely covered. NOTE: SINCE THE JACK'S TABS WILL STICK THROUGH THE HOLE IN THE HEADPHONE FRAME YOU NEED TO MAKE SURE THE WIRES WILL NOT SHORT OUT ON THE METAL FRAME OR WITH EACH OTHER AS THAT MIGHT DAMAGE THE AMP AND/OR HEADPHONES!
9. Mount the 3D printed piece over the frame of the headphones, lining up the holes. Make sure you are using the correct side so the jack is pointing forward. NOTE: I used some blue tak to hold it in place on the frame to keep the holes lined up. Once the jack is mounted and the headphones are reassembled it's quite sturdy so I didn't find it necessary to use a permanent adhesive (but I did leave some blue tak on the inside of the frame to help hold it).
10. Thread the wires/jack through the adapter hole from the bottom at of the adapter. Make sure it doesn't catch on the hole of the headphone frame.
11. Carefully screw the jack into the adapter, making sure it's going in properly and the wires aren't getting twisted/exposed so they don't short out on the frame. NOTE: I had to use pliers to turn it after about halfway in since there wasn't enough to grab with my fingers and there was a lot of resistance. If you do this, make sure to protect the end of the jack to prevent it from getting marred from the pliers. Depending on your printer tolerances and the jack size you might need to mount it in the jack with glue if the hole is too large or print one with a larger hole (or drill it out) if it's too small.
12. Once successfully screwed in, double check with a multi meter that the wires aren't shorting to each other or the frame.
13. Solder the appropriate wires to the driver.
14. Test with a multi meter and the cable you intend to use with the headphone attached to the newly mounted jack and make sure all of the soldering points are correct and none of the wiring is shorted.
15. Reassemble the cup.
16. Repeat the above steps for the other side.
17. Test your headphones and enjoy some music as a reward. :)

Tips:

• I didn't use supports for the hole. I think the rougher texture helped make it easier to thread in the jack.
• This adapter is designed to fit over the headphone frame through the gap between the frame and the cup. If you are using an aftermarket cup that has a smaller gap, this adapter might not work.
• Since it's designed to printed with bed side/bottom of the print facing out, it's advisable to make sure you have a clean looking first layer/line direction for aesthetic reasons. I have not tried other printing orientations since they would require supports.
• Use small flexible wires for the inside of the wires that go from the jack to the driver since it's a tight fit against the baffle and they will need to bend quite a bit.
• Take your time and make sure you are taking all of the necessary precautions. If something isn't working, stop and don't force it. The jacks and wire are cheap, and new adapters can be easily printed, but the headphones and drivers are much, much harder to replace so be careful!