Aluminum diaphragms--can they be replaced?

[jboger]

I have an off-brand reproducer that seems to be made of pot metal. The metal hasn't deteriorated, but the aluminum diaphragm is completely shot, ripped, torn, and the stylus has not been attached to it for a long time. What someone had done long ago was to insert a thin piece of flexible metal behind the aluminum and attach the stylus to that. I have not tested to hear how well that works, although that would be interesting.

So my question is, can the aluminum be replaced with aluminum? I could certainly take a sheet of aluminum of similar gauge and work with that, but it wouldn't have the nice concentric ridges that the original has which (I guess) stiffened the metal and made it more rigid/durable.

Or I could replace it with mica. It would need to be about 2.5 inches in diameter. I've only seen mica replacements for a few, generally common reproducers, so is mica available in odd sizes? From whom?

Aluminum was the original material. I'd like to stick with that, but options are good.

[Django]

Is the aluminum flat? How thick is it?

[estott]

I've seen new old stock aluminum diaphragms, and there are reproduction Orthophonic ones out there.

[jboger]

Here are some pictures. Not sure of the name, maybe Val Phonic? In the first photo you can see the aluminum diaphragm. Next to it is a crudely made piece of flexible metal that someone had rigged into the reproducer presumably after the aluminum was shot. I haven't measured anything yet, but I'd say the aluminum is about 2-½ inches in diameters. Not flat; you can see concentric ridges.the

[epigramophone]

As others have said, replacement aluminium diaphragms are available.

The diaphragm pictured above does not appear to be original to the soundbox as it is too large. The screws securing the front mask should not have to pass through the diaphragm, which should be located in position by the gaskets alone.

[jboger]

I shall look for replacement aluminum diaphragms.

That is a good observation with regards to whether the diaphragm is original or not. Inside the reproducer, the diaphragm was sandwiched between two paper gaskets. They look original. The housing screws did penetrate the gaskets. I'm inclined to agree that it is not original although I'm not 100% sure.

Which brings me to a related point. I have a totally dilapidated pot metal reproducer for which I had no qualms about removing the aluminum diaphragm. Alas, too short, but not by much. I put it in the Val Phonic anyway and battened down the hatches. It worked! Albeit with some unpleasant rubato due to some buzzing of the diaphragm on the high notes.