Pin Signal Description
1 USB +5V in  USB 5V supply - in K750 not used
2 SP_REF  Reference
3 Mic+/AUXIN_L  Microphone+ / AUX Input - left
4 Mic-/AUXIN_R  Microphone- / AUX Input - right
5 DFMS/SP_L  DFMS / headphone speaker - left
6 DTMS/SP_R  DTMS / headphone speaker - right
7 VIDEO/STB  Video / strobe
8 VPPFLASH  Short to pin 9 for handsfree detection
9 GND  Ground
10 CTMS / USB DATA+  CTMS / USB+ (data) - in K750 not used
11 CFMS / USB DATA-  CFMS / USB- (data) - in K750 not used
12 Charge In  Battery charging  (+5V) - in K750 not used
 Used Shortcuts:
 
 * CTMS stands for Control To Mobile Station
 * CFMS stands for Control From Mobile Station
 * DTMS stands for Data To Mobile Station
 * DFMS stands for Data From Mobile Station
 
 Notices:
 
 The key is near pin1

 If you want make a stereo converter with a SE socket, you will be used 5 and 6. pins. It may not work well with an amplifier due to low output i.e just enough to power for headphones . (May need pre-amp).