The Talking Machine Forum — For All Antique Phonographs & Recordings

As many of us know the mica diaphragm can become fatigued or damaged over time.
I have rebuilt many soundboxes (reproducers) and it seems that after 80-100 years, it has always been good to also change the mica diaphragm. My customers have always been satisfied with the sound of their rebuilt reproducers. I think this also is in part to changing the diaphragm. (I always include the old diaphragm so that the customer can keep it). Some purists may say this alters the value of the machine, others say if the mica is intact why replace it? In my humble opinion the mica should be changed just as the gaskets for a proper reproducer rebuild.

What are your thoughts on always replacing the old mica diaphragm?

I agree with you that a new mica diaphragm can vastly improve the tonal qualities of a reproducer.
In the past I have had them rebuilt with new gaskets but the original mica. These have been an improvement, but where some visible delamination has occurred the high pitched notes can be heard with a slight buzz.
I now replace the diaphragm with a new mica and, as with Victrolacollector, keep the original with the machine.

On Gramophone type reproducers I would say replace with a new mica diaphragm, this represents a good tonal improvement. On Edison cylinder reproducers, the new mica is thick and not stepped, they do not sound as good as the old stepped mica. I actually like the sound of the stepped mica over the copper diaphragms in the C reproducers.