Question About Gaskets

[Whittington]

I have recently been rebuilding some of my reproducers as none of them have had that luxury since I have owned them. I know that it is probably THE most important aspect of improving sound on a phonograph. Instead of sending them away to be rebuilt, I decided to learn on one that isn't being used without any reference material. I find I can learn the process better and end up with a more thorough understanding of everything this way.

Anyway, I rebuilt a model C reproducer which is abou as easy as they come and ordered a new copper diaphragm and gaskets online to do the job. It worked well from what I can see and hear. No problems at all. Here is my question, can anyone tell me, or point me to a website that has the exact dimensions of the gaskets used in different reproducers? I am currently rebuilding a Diamond Disc reproducer. My Dad is an engineer and has access to about anything mechanically speaking under the sun. He told me to get him the dimensions and he would supply as many gaskets for my reproducers as I would need, including options of several different materials. I though it would be interesting to test a few of these materials out, but need the exact dimensions of the gaskets to give him.

Anyone know what the dimensions of a Diamond Disc reproducer are? Is there a reference site I can refer to for gasket dimensions for all Edison/other reproducers? Thanks for the help!

First rebuild of a Model C.

Before


After


Even cleaned the stylus

[JohnM]

I have long speculated that sheet graphite fiber would be an interesting material to try for diaphragms -- dimensionally stable, airtight, strong as steel, impervious to changes in temp and humidity. Please let me know if your dad ever tries it! Thanks!

[Whittington]

Thanks John, please check your personal messages.

[Brad]

I have never seen gasket "specs" for various reproducers. The APSCO catalog says to tell them the size or the diameter of the diaphragm. That is probably your best bet. You can alway use the old gaskets as a starting point.

Experimenting with different materials and thicknesses does sound like an interesting experiment.

[phonojim]

Edison reproducers almost always have a tab washer between the ringnut and outer gasket. You could probably measure the tab washer to determine the inner and outer diameters of gaskets. If you wanted to be even more exacting in determining the outside gasket diameter for a snug fit, you could measure the ID of the reproducer housing. Measure at the the innermost, unthreaded part of the housing ID.

Jim

[larryh]

While your at it, don't make the new gaskets too wide. Some of the new ones are about half again wider than edison used and I feel they are detrimental to the overall sound volume. If you get a good soft rubber gasket that is the correct sizing I might be interested in a few for my experiments on diaphragms. Another problem some new ones suffered from is they evidently are either too undersized or shrunk after they were cut causing them to not go out to the edges of the housing like they should, making centering the diaphragm on them impossible.

[SonnyPhono]

Thanks for all the valuable advice. I am using the metal ring that sits between the gasket and ring that screws to tighten everything. I am going to have a punch made with those dimensions and will experiment from there. I have a couple of ideas for materials to try and will keep this thread posted. Thanks again for the help!

[JerryVan]

I make my gaskets from silicone rubber supplied by McMaster-Carr. I made my own punch that does the I.D. & O.D. at the same time, assuring concentricity. My gaskets are .015 thick. Most gaskets supplied by others are just too thick. Also the case with Orthophonic gaskets, which I also make from silicone rubber.

See http://www.mcmaster.com/#86435k43/=4di29c

[JerryVan]

Thanks for the insight, Walt. I am certain that you are correct in all that you state, however, I find that at least having a gasket of the proper thickness, regardless of the material, is a huge improvement over gaskets that do not even allow the Orthophonic lock rings to screw in. I am very pleased with the performance of the silicone rubber gaskets over worn out originals and poor quality reproductions. I would say that the silicone gaskets perform very well, but will easily admit that they are probably not optimum. The problem is; I don't know what would be optimum.

I am certainly open to refinements in material. Can you suggest a modern day replacement more in keeping with the original design intent?

By the way, the other reproducers in which I use silicone gaskets are Edison C's, H's & K's. Do you see any negative impacts in those applications?

[frankt]

i have an orthophonic reproducer (portable type) that has never been rebuilt, the back ring has a crack, therefore it is impossible to remove it for a rebuild. the only thing i did was replace the bearings and back flange. as for sound output, i would put it up against any professionally rebuilt reproducer out there. it has strong bass and very clear midrange. i have used the neoprene gaskets in the past and find they perform as good as this "original" reproducer.