Why?
- Well the reason for this experiment was that the new Macbook Pro 13.3 only has a single audio out/in jack. The Operating System allows you to change it to input or output. After using my nice headphones with a microphone built in I was saddened that I could not use these. I had to sacrifice one or the other.

- Now when I was browsing the apple support forums one user said the Macbook will allow you to use your iPhone headphones and be able to use the microphone as well!! AWESOME! Now I had to find a product that could do just that.

- After obtaining the DLO headphone splitter (because it says it supports mic input), it didnt work.
The problem is in the pin outs of my and most common 3.5mm mic jacks use the tip as the signal and the sleeve for the ground (pic will follow). Apple uses the sleeve for the mic and a common ground in the middle.
Time to change that!!!

Step 1: Tools and Parts

You will need:
- Soldering Iron
- Solder (resin core most popular)
- Pliers
- Diagonal Cutters
- Small Flat Head Screwdrivers
- Small guage wire
- Helping Hands (not needed but they do help!)
- X-Acto Knife
- Patience

You can get the D-LO adapter from e-bay (for about 15 bucks)
part number: DLZ70003 or DLZ70003/17
Product Link: http://dlo.com/Products/cable_headsplit_Prod.tpl

Pin out reference: http://pinouts.ru/PortableDevices/iphone_headphone_pinout.shtml

Step 2: Disassembly and Reason

- Pry open with a small flat head screwdriver at the seam between the two jacks. Dont be afraid to dig in there prying up and down to crack the glue seam. Work around all the sides to ensure a clean separation.

- Now the fun begins, note the pin outs before we start hacking the splitter up, what we are going to do is make this adapter so that it is an exclusive headphone / microphone adapter (YOU WILL NOT BE ABLE TO USE THIS FOR TWO PEOPLE TO LISTEN LIKE IT WAS ORIGIONALLY INTENDED). The reason that this does not work properly with the Macbook pro is that the microphone jack most headsets use is not the same pin out as these adapters. We have to swap the mic jack pins to make this work properly.

Step 3: Cutting the Traces

- Once we crack open the case and lift out the PCB we are going to have to cut some traces.
Cut all the traces where I have circled EXACTLY in red carefully, you dont have to remove it all just about 1mm of gap until the copper trace does not show (again, you do not have to cut all the way through):

What we are cutting is the mic, left, and right traces so that we can successfully re-wire our jack to be an exclusive mic jack!

Step 4: Soldering

- Using the same pic again, grab a small amount of wire ( I used an old cd-rom audio cable), measure it out first (about 1 inch) and solder the wire where the green square is to the blue jack and then solder the wire to the black wire (it is actually a braided wire with a rubber sleeve not the black wire near the red wire).

Note that there is a solder pad there on the PCB to make it easy. If the braided wire comes off the PCB try and get it back on there. If all else fails just solder the wires together and tape them up so they do not touch any other exposed connection.

Step 5: Finish!

- Take a break for being such a steady hand! :D

- Test out the adapter before you snap and tape it up. Go into the System Preferences, click sound settings, and plug in your headset and mic to the adapter, then plug into the Mac. You should see the audio jack say Headphones with External Microphone. Try it out!

- Now the black jack will always be your headphone input and the blue will only be the mic input!

This was my first Instructable please let me know how I did!