I have a stereo headset previously used with Nokia 800 tablet. The headset has an integrated microphone and on/off switch in the microphone "pod". The connector has a 4-section 3.5 mm plug that fits into headset connector on g-tablet. I have been unable to make this headset work with g-tablet running vegan 5.1 ROM. Using the sound recorder software, the g-tablet built-in microphone seems to be only possible input.
I also have a bluetooth stereo headset (Samsung SBH500) with its own microphone. I have also been unable to record sound from this headset.
Both Nokia and Samsung headsets reproduce stereo sound from the g-tablet.