The Talking Machine Forum — For All Antique Phonographs & Recordings

I recently brought home a Columbia BV graphohone. This is a rather odd machine as the reproducer is integral with the carriage and cannot be removed in one piece. I am working on getting the machine back to its full playing potential. The original mica diagram was replaced with an edison copper one. Does anybody here know how thick the original mica diaphragm was? I assume it was a stepped mica diaphragm or am I incorrectly in this assumption?

Thanks,
Stephen

Hi Stephen, yes, the BV uses a stepped mica. It is simply glued into place. I have a BVT that is an undisturbed original. Unfortunately I do not know the thickness.