K750i headset - 3.5mm jack mod (with pics)

**Kman79** · 06-14-2005, 09:32 AM

Originally Posted by Judderman

OK, I have added a pic below that explains what my estimations of what each ID mark may mean...

To transfer a stereo signal you will need 3 wires. The SE headset contains these 3 wires plus 2 additional ones to work the mic.

If you get a stereo socket, the lead will contain 3 wires. Almost always copper (the common ground or -ve), red (right side +ve) and another colour (left side +ve).

You can connect the red and copper to the (S+) and (S-) connections respectively. All that is then left is to connect the left signal wire to the correct place. On my headset there is no connection on the board for this which is why it is connected directly to the green wire poking out the end of the headset lead..

Kman79 - from reading your description you may have a terminal on the board for this, namely LS (Left Speaker?). Look again closely at where the wires from the left earphone go on the board. The one with 2 wires wrapped together will be the common speaker ground (SG in my case but -G in yours) If the other one goes to LS then this is where you will need to attach your last wire.

** This is in my opinion only however and I accept no responsibilty if this is wrong and any damage is caused as a result, although I believe this unlikely**

Couldn't have explained it better. Thanks for the diagram up top, that helps out alot. Thanks again

**rabvtec** · 06-14-2005, 01:08 PM

Totally agree guys! Judderman, thanks for taking the time to explain everything to us (once again

)

**beatniks3** · 06-15-2005, 09:27 AM

bump for an answer to my pic post (and for anyone who hasn't seen this link yet)

**wardseward** · 06-17-2005, 06:17 AM

Hey Turt,

When you cut the cord on your Sony earphones how many cords were in there? 2 or 4? Also, in your photo I see the left ear cable going into the top of the mic box, but where is the right one going? In the bottom? If so, why did you do it that way? Just wondering, Thanks.

Originally Posted by turt

Strange, my message disappeared

Basically I was saying this:

**ecsw** · 06-17-2005, 04:28 PM

I would like to know about this too

Originally Posted by beatniks3

great post Judderman! you don't happen to know where the different leads lead back to the phone connector piece do you? only the 3 stereo wires and where they attach to the phone are needed for my experiment.

can you fill in the numbers on my awesome paint pic? thanks in advance:

**rabvtec** · 06-17-2005, 04:40 PM

Originally Posted by wardseward

Hey Turt,

When you cut the cord on your Sony earphones how many cords were in there? 2 or 4?

@ wardseward
I've did this excellent mod a few days ago - here's how I did it following the advice from here. BTW, when you cut off your Sony 3.5mm socket, there's 3 wires in there (copper, red and green).

I completely unsoldered everything so to make a clean start. On the socket side - I soldered the copper wire to S-, the red wire to S+ and the green wire to the green wire from the SE handsfree. Then on the SE handsfree side - I soldered the black wire to G-, the white wire to M+, the blue wire to RS, then I carefully gathered together all the copper strands, twisting them together and soldered them to SG. Gulp ... I hope that's not too confusing

I did a new clean cut on the handsfree side, carefully slit and peeled back the sheath and snipped it off to expose the wires. I then, again carefully, stripped each wire to reveal a small piece of each for soldering. This way I could determine the length I needed for each by regularly offering it up to the PCB.

Don't get me wrong, for a first time, it is daunting but my advice is a patient, slow and methodical approach - pays dividends!!

I know your post wasn't addressed to me but I hope this helps ...
ps You also wanna completely untangle the 'long' SE earbud from the handsfree case side and get it out of the way ... I found that really helpful

**wardseward** · 06-17-2005, 10:35 PM

Well, here is my delima. I am moding a headset for an Audiovox 5600 and the mic bud has 4 connections for the earphone side. R+, R-, L+, and L-. But, I guess the Sony earbuds only have three wires. Anyone have any guesses about what I should do now?

Oh, and on the plug side it has the same connections plus a mic+ and mic-.

Sorry about the bad photo.

**scaredyet** · 06-18-2005, 09:25 AM

im thinking of doing the same thing. ı was thinking of getting the white pair of the same earphones he used what do you think? black or white

**rabvtec** · 06-18-2005, 10:19 AM

@ scaredyet

ı was thinking of getting the white pair of the same earphones he used what do you think?

Are you talking about the Sony MDR-EX71? Black or white...? Well IMO, I'd go with the black as they'll match the phone better. However (and this depends on way you stay/hang out), there's always stories in the local press about ppl being rolled for their gear cos neds seem to think that you might be packing an iPod!

@ wardseward
Yikes, I can't really help you there, I'm afraid. However, what are the colours of your 4 wires as that might give us a clue? If one of them happens to be black (-ve), then it might just be the case of running that to the other side of the SE PCB and soldering it with the other one to SG - just a suggestion ...

**GT-[R]** · 06-19-2005, 04:09 AM

Originally Posted by ecsw

I would like to know about this too

ecsw are u planning to make one?
if its successful u wanna help me out too? haha :P

**eazee** · 06-19-2005, 11:21 AM

Originally Posted by GT-[R]

ecsw are u planning to make one?
if its successful u wanna help me out too? haha :P

and me I'll pay ya 40 bucks.

**furballz** · 06-19-2005, 10:48 PM

Originally Posted by wardseward

Well, here is my delima. I am moding a headset for an Audiovox 5600 and the mic bud has 4 connections for the earphone side. R+, R-, L+, and L-. But, I guess the Sony earbuds only have three wires. Anyone have any guesses about what I should do now?

Oh, and on the plug side it has the same connections plus a mic+ and mic-.

Sorry about the bad photo.

I'm not 100% sure but from past experiences, i think you can connect R- and L- (bare wires right?) together: basicaly, sony uses a common ground for the L/R output (it's pretty common). Easier solution, just connect the sony earbuds ground wire to either R- or L- : the worst that can happen is that you'll have no sound on one of the earbuds (unlikely though!)

Wasn't too interested in the mod at first but guess i'm now forced to do it (my L headphone just died today!!