2.5mm or 3.5mm

Mike Montour mail at mmontour.net
Fri May 30 23:18:23 CEST 2008

Joerg Reisenweber wrote:

>> http://www.meritline.com/earphone-adapter-iphone-into-3-5mm-mic-038.html
> This one is completely off topic. I'm talking about STEREO headSET(=with mic), 
> which usually commes with 2.5mm. 
> We are planning to use a 3.5mm 4-ring connector, that complies with usual 
> 3-ring headPHONES(=w/o mic), and I didn't see an adapter 
> 3.5/4wire-male->2.5-4w-receptacle yet. So you probably have to DIY, to 
> use "standard" headSETs with future OM devices. But you get benefit of 
> plug-and-play for classic "Walkman(R)"-headPHONES.

I don't see how it's "completely off topic" as it's an example of a 
commercially-available adapter with a 4-ring 3.4mm plug (even if the 
other end of it isn't what's wanted).

I understand the benefit of "plug-and-play" for regular headphones - 
that's why I voted for the 3.5mm option. However I also feel that it is 
important to have at least one commercially-available headset (or 
headset+adapter) that can be used without requiring DIY cable assembly.

I don't have an iPhone, but it looks like it uses a 4-pin 3.5mm 
connector that is electrically compatible with regular 3-pin 3.5mm 
headphones (just mechanically recessed so that you have to buy 
"official" adapters). If that is the case, then OM might be able to use 
a non-recessed 4-bin receptacle with a compatible pinout. That way, any 
iPhone adapters or headsets could be used with the OM phone.

BTW I did a bit more searching and found another adapter that may be 
closer to what you are looking for:


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