The Talking Machine Forum — For All Antique Phonographs & Recordings

A good idea yo send him the old isolator as part of payment.
Thanks for the info.
It's for my new French hmv no.3 tabletop. I'm overhauling the exhibition soundbox.
The soundbox has lost its black painting and white lettering inside, what is seen through the mica, and I'm doing some trials to see how to repaint it. I've tried black painting "water enamel" but first layer only... The soundbox back has been polished to clean bronze, and I don't know what prime must I use. I've tried a first prime of the black paint, but dunno if it will work.
Other small black touches I have made to small parts in the past were done using black nail enamel, and it worked well... Maybe I'll try that if the paint doesn't work well.
I don't know still how to add the white lettering...

Actually, the back part of the Exhibition was not painted but blackened brass. Some years ago, I did had mine refinished with a matte black chrome finish that looks perfectly right and was going to give the best results. I used titanium white (zinc white was probably used originally), applied it with a cotton swab and carefully wipe off the excess material. The front part got nickel plated and the whole reproducer looks fantastic. I used the soft rubber gaskets and a new rubber flange from Ron Sitko and put in one of my glass diaphragms, very happy with the end results, both visually and sonically.

Ah, chemical blackening, then. And after that, careful painting of the white letters.
Ok, thanks for the tip.
I'll look for the products to bath the brass back in my local restoration materials shop.
Are you selling those glass diaphragms of yours? If that's the case, what is the price?

A did send my part to a shop which does all kinds of galvanic metal works. They said, another blackening of this brass part might not become evenly black again. So, the black chrome plating was the alternative they suggested. And I really like it.
Yes, I still have some Exhibition sized glass diaphragms in stock which I once had custom made. The price is $14.50 with international shipping. It takes some extra care to install these and the center has to be glued as there is no hole (the original ones never had one either). For this, I use clear epoxy, very, very little of it. It can be removed easily from the bar, if necessary. I normally use a wooden toothpick to install the upper rubber gasket part. It takes some patience but usually works great. If you prefer to get it installed, you can also send in your reproducer.

Super glue would also work for the needlebar foot attachment to the glass?
Pardon me, but I don't understand why you have to use a toothpick for installing the upper rubber gasket... Cannot be installed by hand on top of the diaphragm as in other soundboxes? Or it is because you don't have the center hole available for pushing the diaphragm into the correct centred position?

Super glue does also work but can leave an ugly white shadow behind. If used, gel should be preferred. I just use the toothpick to push the front gasket inbetween the reproducer ring and the diaphragm. This does prevent the diaphragm from breaking because wood is much safer than using a screwdriver or a knife. The glass diaphragm is installed otherwise like a mica type, just with more caution plus the glue. That's all.

That black chroming looks fabulous!!

But I think you guys are wrong about the original diaphragms not having holes in them. I have two Exhibitions, one from 1914 and one from 1909, and on disassembly both were found to have mica diaphragms with holes in the center. A tiny screw went through the center of the needle bar, with a thin rice-paper washer behind the screw. The entire center was fixed to the diaphragm and isolated against buzzing by a tiny drop of red beeswax (the low-grade, gummy wax used to seal the internal horns on early Victrola machines) that had been melted.

Both machines were extremely original. The Victrola had been fifty years in a barn and I was the first to overhaul it, and the 1909 horn gramophone had been sealed up in its original box for about 90 years more or less, so it also had never been overhauled.


(Unless you guys are talking about center holes in GLASS diaphragms. I haven't heard of Exhibitions having those from the factory but it's a fairly popular upgrade to the original design. Wouldn't know but it does seem tough to poke holes in glass...)

That's the point. Modern glass diaphragms have no center hole.