http://openbci.com/forum/index.php?p=/search&Search=saharabox

Yes, you do need additional "boxes" on top of the g.tec amplifier, which is troublesome when you want to use their electrodes -- the g.saharabox or g.gammabox is twice the size of the OpenBC

If you look at the way g.tec did their g.SAHARA active dry combs, they have a separate box (g.SAHARAbox) that does this translation. The output of that box goes into their amp which can then be either

gain can be set as you desire.  The g.SAHARAbox converts the actives into essentially passive electrode voltage range.

I priced this back in 2011, and hope these are obsolete figures.  :-)  But at that time a single active electrode, plus it's connection wire to the g.SAHARAbox was about $270.  Pricing for the referen