Contact Lamptron, they should take care of you. AFAIK they've handled these on an individual as-needed basis just fine. The ones I had were prototypes, but the new revisions are in production AFAIK. Just contact their support.
I don't think the FC-5 ever had a v.2. Its original was a design that didn't squeal. The FC-2 and FC-3 are the ones that have been redesigned.
Bookmarks