Can You Convert a 2.5mm Phone Jack to Dual 3.5mm Jacks?

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Discussion Overview

The discussion revolves around the challenge of converting a 2.5mm phone jack to dual 3.5mm jacks for a headset, specifically addressing the compatibility issues between a landline phone and a headset designed for a PC. The conversation explores potential solutions, including wiring modifications and the nature of the connectors involved.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant describes the need to convert a 2.5mm jack to two 3.5mm jacks, noting that a simple Y-connector would not suffice due to the different functions of the connectors.
  • Another participant suggests soldering the 2.5mm connector from the old headset to the new headset's wires as a potential solution.
  • There is a discussion about the compatibility of the new headset with a landline phone, with some participants expressing skepticism about the feasibility of using an adapter.
  • One participant mentions that the 2.5mm plug typically has a specific wiring configuration, with the microphone on the tip and the headphone and ground following.
  • A question is raised about why a microphone and a single earpiece would have three contacts, leading to speculation about the use of stereo plugs for cost reasons or the presence of multiple microphones for noise cancellation.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of using an adapter and the compatibility of the headset with the landline phone. There is no consensus on the best approach to achieve the desired conversion.

Contextual Notes

Participants note the specific wiring configurations of the connectors and the potential implications for compatibility, but the discussion does not resolve the technical challenges involved in the conversion.

Who May Find This Useful

This discussion may be useful for individuals seeking to adapt headsets for use with landline phones or those interested in the technical aspects of audio connector compatibility.

DaveC426913
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My cordless phone (No not a cell phone, this is a landline. They still exist, you young whippersnappers.) worked with a head set thus:
http://www.maxiaids.com/ProdImages/9700750.jpg
which has a 2.5mm jack. (It looks like a stereo jack i.e. three contacts but of course, it won't be stereo, it will be speaker and mic)

I wanted a smaller, lighter headset so I bought something like this:
419083H1JVL._SL500_AA280_.jpg

Problem is, it has two jacks (one for speaker, one for mic, colour-coded pink and green) and they are 3.5mm (and also three contacts).

I don't have a problem converting from 3.5 to 2.5, my difficulty is converting from single connector to this double connector. Clearly I can't simply use a Y-connector, since all that will do is feed the speaker and mic lines into each other.

Is there an adapter like what I'm looking for? What can I do?
 
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They didn't sell a headset compatible with your phone?
 
Chop the 2.5mm 3way off the old headset and solder it to the wires on the new headset?
 
the new headset is for a PC. On most sound cards, the inputs are also colour coded (pink and green) for mic and head phone 3.5mm jacks. This headset, as far as I can tell, was not intended to be used with a landline telephone. Using an adapter won't cut it I don't think. Still got the receipt? :wink:
 
redargon said:
This headset, as far as I can tell, was not intended to be used with a landline telephone. Using an adapter won't cut it I don't think. Still got the receipt? :wink:
I don't see why not, the microphone is going to be a standard electret and the headphones are all the same.

ps. the 2.5mm plug is normally microphone on the tip, then headphone then ground.

http://ca.geocities.com/mstudi@rogers.com/retro.html
 
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They didn't sell a headset compatible with your phone?
They do but not the type I wanted. I was optimistic about thinking it would be a simple matter of finding the right adapter.

mgb_phys said:
I don't see why not, the microphone is going to be a standard electret and the headphones are all the same.

ps. the 2.5mm plug is normally microphone on the tip, then headphone then ground.

http://ca.geocities.com/mstudi@rogers.com/retro.html

Thank you. That is exactly what I needed. (Failing finding a pre-made store-bought one that is...)

OK, only one issue left. The green/pink connectors are also 3 contacts, which means I have one contact each too many. Why would a mic connector have three contacts? And why would a single earpiece have three contacts?
 
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DaveC426913 said:
Why would a mic connector have three contacts? And why would a single earpiece have three contacts?
Either there are two microphones - one facing toward you and one away so it can do noise cancellation - OR they used stereo plugs because they are more common and cheaper.