Headphone jack

I took this headphone jack out of an old busted iphone 3g. I was wondering if anyone can tell me which terminal is which or how to test and find out which is which?

FullSizeRender (49).jpg

FullSizeRender (49).jpg

Get a 3.5mm TRRS jack and a multimeter or continuity tester.

But I would have to peel the wires from the headphones, right?

Not if you buy a bare TRRS jack

But I would have to peel the wires from the headphones, right?

If you just want to use it for headphones, plug-in your headphones and randomly connect a 1.5V battery while listening for a "click".

You'll get a click when you make the connection and a click when you break the connection, but nothing when constant DC is applied. It might be a little loud, so try it without the headphones directly on/in your ears first.

If you get connected between left & right (with no ground) you'll hear a click in both ears.

Ok I get click when connecting any two of the 4 corners of connectors here marked in red:

CORRECTION:

I get a click anytime I connect either of the 2 terminals on the left, with any of the two on the right.
I get nothing when I connect both left terminals together or both right terminals together.

Then, you're good to go, right? If you're getting a click with a battery you can get sound from an amplifier or other audio source.

There should be 4 connections to the actual socket (ground, left headphone, right headphone, microphone.) There may be two grounds or an unused pin for mechanical solder strength. And with a regular TRS (3-connector) headphone plugged-in, the mic connection may be shorted to ground.

This is the diagram of the circuit I'm trying to create. I would need 1 wire to ground and 1 wire to the pot.

Maybe a school, perhaps somewhere in India, assigned a project to connect a microphone, amplifier and speaker? We got a really similar question over on the Teensy forum…

https://forum.pjrc.com/threads/35212-Mains-noise-problem-and-reduced-sensitivity

Even if it’s not the same project, there is a striking similarity in schematics. Maybe some of the info there will help?

But I would have to peel the wires from the headphones, right?

...This is the diagram of the circuit I'm trying to create. I would need 1 wire to ground and 1 wire to the pot.

You can't drive a speaker or headphone directly from an LM324 or through a 10K pot. That schematic could be for driving a piezo transducer or it might just be wrong. A 100 Ohm pot should work for 32-Ohm or 64-Ohm headphones, but I wouldn't try one with a speaker.

A proper design would use an audio power amplifier chip (designed to drive headphones/speakers) and the volume control would be at the amplifier's input.

Since nobody here has the part number or specifications for your particular connector, you'll have to figure it out yourself. Or, buy a part from a reputable supplier where you can get the specs & connection diagram. [u]Here's an example[/u].

Well the speaker is just a speaker in the schematic. Its actually a pair of iphone headphones.