I’ve been looking for a 4 conductor male TRS connector (Apple iPhone headset jack) for a small project. Simple enough. I found a cheap extension on Amazon a week ago that seemed to fit the bill. For posterity here’s what the description says:
Technical Details
- Made and designed to work seamlessly with the Apple iPhone.
- Will act as an extension cable, carrying both the stereo audio and microphone signals from your device.
- Allows the adapter to be used with stereo headphones that also have integrated microphone functionality
- Made with Nickel plated materials, 3.5mm 4-pole plug, 3.5mm 4-pole jack and a 10 cm (L)
- A perfect accessory for your NEW Apple iPhone.
Emphasis mine.
It arrived in an envelope containing a tiny ziplock back with no labeling (it’s barebones). When I hooked it up it seemed that audio quality wasn’t very good. I never bothered to check out the microphone. At that price it obviously didn’t make fiscal sense to return it as the postage costs about as much as it’s worth. So I decided to finish dissecting it.
From what I can tell it’s actually 3 wires. Each is a different color (red, copper, green) with some white strands in the core. The female jack has two prongs with one wire attached to each and the enclosure itself which seems like it’s the ground. My suspicion is that the audio is either combined or only one channel is used making it actually mono. The jacket I dissected was molded on so it was virtually impossible to remove the plastic without severing the thin wires in the process.
Here’s what the wire and the female jack (sideways on the bottom) look like:
Here’s the jack from the back side. I suck at photography and only have a P&S camera, so it’s a bit blurry:
I’m now debating trying another vendor or a more expensive 2.5 mm to 3.5 mm adapter.
My original plan was to find a new 4 conductor TRS male plug, but that proved impossible via the usual sources. 3 conductor is easy.
If anyone has suggestions feel free to reach out.