====== Connecting wired stereo headset ======

===== Hardware =====
The headset receptacle is a 3.5mm audio socket with 4 poles. The poles are arranged in a way allowing for standard unmodified stereo headphones to be used.

{{:audiojack4pin.png?|Pinout from http://www.allpinouts.org/index.php/File:Connector_minijack4pin.png}}
The pins are:
  * 1 (tip) left HP output
  * 2 right HP output
  * 3 GND
  * 4 (sleeve) microphone

AC100 can use a regular [[http://en.wikipedia.org/wiki/Electret_microphone|electret microphone]] connected to the 4th pin.

NB: some noname 4-pole jack i bought for a DIY adapter was impossible to insert before filing its tip.

===== Compatibility =====
This arrangement is compatible with the numerous iPhone headsets and is not compatible (without hardware mods) with the scheme used by Nokia.