hi richard,
that's make perfect sense then, you have some connection
when i saw 2 fg1 at online auction years ago both were located in japan
i remember that ebay listing but didn't see any fg1 on their listing, mostly was hp1000 and some prototype models. those fg1 probably gone in seconds, yeah i also remember read those parts about ps1
so i'm guessing you only have the headphone itself? not the whole system with the wireless receiver and amp?
haha headamp using a really great design by kevin gilmore, i haven't get a chance to try any of his design but will do someday, yours should improve a lot with GRLV psu