The Talking Machine Forum — For All Antique Phonographs & Recordings

This is made entirely of brass - although I had to add a needle screw which isn't.

Also, I am unsure as to what the 'spider-like' diaphragm is made from.

Any-way, I would be grateful for any id information as I have never seen another one like it.

Thanks very much for any help you can give.

Most unusual. Are those four holes around the circumference to secure the gasket and diaphragm, or do you think there was a diaphragm guard fitted there previously?

That must have been on a high end machine, since it's not pot metal. I would find a machine to use it on, in place of generic hardware or make a special project machine with this as the basis.

An Balores wrote: Sat Jan 13, 2024 1:59 pm Most unusual. Are those four holes around the circumference to secure the gasket and diaphragm, or do you think there was a diaphragm guard fitted there previously?

I think they are just to secure the gasket.

Curt A wrote: Sat Jan 13, 2024 1:59 pm That must have been on a high end machine, since it's not pot metal. I would find a machine to use it on, in place of generic hardware or make a special project machine with this as the basis.

Interesting. Thanks Curt.

I think maybe it was a 'one off' exhibition type piece maybe ? I am only guessing though.

Great idea about trying on a spare machine or a special project !

An Balores wrote: Sat Jan 13, 2024 1:59 pm Most unusual. Are those four holes around the circumference to secure the gasket and diaphragm, or do you think there was a diaphragm guard fitted there previously?

I was just having a close look at these four holes and surprisingly (to me) they do not contain screws. It seems that the inner brass ring actually twists off. I guess a special tool was used which engaged all four holes with small metal prongs.

Also, I am beginning to think that it may be a 'Sonora'. I do not know anything about this gramophone brand but one or two of their tone-arms look vaguely similar. (Two photographs 'below'). Particularly the part which joins the sound-box - kind of an odd 'dippy' shape. Also, the sound-box can be adusted to be side-ways onto the record or turned 90 degrees. Like the chrome one in the photograph below.

Some-what oddly I think that the diaphragm is made from very thin brass too.

So maybe a very early Sonora ?

If you decide to part with it, I would be glad to figure out something to use it on...

Curt A wrote: Sun Jan 14, 2024 9:14 am If you decide to part with it, I would be glad to figure out something to use it on...

Okay, if I ever do I will let you know !

Thanks...

I vote as our colleague. It looks so interesting and well constructed... I would build a machine around this tonearm, and I would add a huge, well designed exponential horn that could be at the same quality level as the tonearm and soundbox, just to use them. I'm sure it would sound wonderfully...