The Master-1G and Master-1S are the same headphone. The Master-1S is the North American version/name for the SE-M10. A Master 1S showed up on eBay, new in box, some few months ago. I haven't seen one since. The Master-1G is unobtainium. Personally, what I REALLY want to find is the SE-1000 electrostat, but it's so rare that I don't know if it was ever actually produced.
11/2/14 at 5:32pm