The Talking Machine Forum — For All Antique Phonographs & Recordings

Dale H,

I am the member who posted the pics of the producer on the other thread. I too am trying to identify this producer and find a source for gasket material to use to rebuild it. If you have any luck please post a follow up here. I'll do the same.
Thanks!!

Randy

I have mine all apart, mine is the same and I only paid 20 bucks for mine, I bought it just because the pot metal is in top notch condition.
The rubber mount on mine was shot, I plan on making a new one out of stock Neoprene or a type of hard rubber on my lathe _ the old orange one was hard and crumbly.
I'm going to make the new one fit a Victor out-side-horn machine.

I also plan on using the white round gasket materiel that's used on the Exhibition reproducers, it seems to be just the right size to properly compress the edges of the diaphragm.

Jeff

This is what I used for the mounting gasket.

Randy

JeffR1 wrote: Fri Dec 31, 2021 4:44 pm I also plan on using the white round gasket materiel that's used on the Exhibition reproducers, it seems to be just the right size to properly compress the edges of the diaphragm.
Jeff

Hi Jeff:

What's the diameter of the shell? Soft flat gaskets would be preferable, but Exhibition sound box gaskets will probably work okay. You'll want to make sure that the seal around the edge of the diaphragm is completely air tight. You can test it by blowing VERY GENTLY into the throat of the diaphragm once the gaskets and diaphragm are in place. If it isn't air tight, you can apply a very thin layer of silicone calk to the portions of the gasket surfaces touching the sound box's shell and diaphragm. (A micro-thin amount of shellac will also do the trick, but you have to work very quickly.)

OrthoFan

OrthoFan wrote: Fri Dec 31, 2021 9:16 pm

JeffR1 wrote: Fri Dec 31, 2021 4:44 pm I also plan on using the white round gasket materiel that's used on the Exhibition reproducers, it seems to be just the right size to properly compress the edges of the diaphragm.
Jeff

Hi Jeff:

What's the diameter of the shell? Soft flat gaskets would be preferable, but Exhibition sound box gaskets will probably work okay. You'll want to make sure that the seal around the edge of the diaphragm is completely air tight. You can test it by blowing VERY GENTLY into the throat of the diaphragm once the gaskets and diaphragm are in place. If it isn't air tight, you can apply a very thin layer of silicone calk to the portions of the gasket surfaces touching the sound box's shell and diaphragm. (A micro-thin amount of shellac will also do the trick, but you have to work very quickly.)

OrthoFan

Diametre is 1-15/16th

It's funny, I just picked up an RCA Victrola O-1 this afternoon and this is the reproducer that was on it...
It appears there were only a little under 1,500 of them produced, probably for the best, it's a far cry from my VV 2-55. But for $20 and a handful of Canadian pressed 78s I won't complain

I also plan on using the white round gasket materiel that's used on the Exhibition reproducers, it seems to be just the right size to properly compress the edges of the diaphragm.

I read somewhere, probably on this site, that reproducers with aluminum diaphragms are better with slightly more rigid gaskets because the aluminum is more flexible than the mica diaphragms. Not sure if this is one man's opinion or if it is common knowledge.

Dale H

Probably it's true. Some came with flat thin rubber gaskets. Hmv no5a/b had flat thin felt gaskets. But the radial corrugations of Victor orthophonic near the edge of the diaphragm are consistent with this philosophy. Other diaphragms as the Viva tonal and most brands only had concentric corrugations, and I think these work better with tubular gaskets, tight enough to make it airtight, but not too tight. The gaskets should not be hardly pressed when the soundbox is assembled. These concentric diaphragms are less flexible and work better if a little rotation at the edge is allowed.

Inigo wrote: Sat Jan 01, 2022 7:08 am But the radial corrugations of Victor orthophonic near the edge of the diaphragm are consistent with this philosophy....

This illustrates how the corrugations enable the plunging action of the Victor/HMV Orthophonic style diaphragms:


(If the image does not display, click on: https://i.makeagif.com/media/9-12-2015/HaqbP4.gif )

OrthoFan

Even in this case, notice the slight rotation of waving oscillation of the diaphragm edge.
I prepared a hmv 5a soundbox with less pressure on the diaphragm edge, just the minimum amount needed to maker it airtight, and noticed that in this position, the back of the soundbox was not completely pressed to the front ring, leaving a gap all around, and the screws not fully screwed in. I fixed all in this position, and sealed and secured the gap and the back screws with white vinyl glue. It resulted in amazing performance of the soundbox, so I did the same to all my 5a/b and no4 soundboxes, and they all perform beautifully. The secret I believe is to allow for that little edge movement, resulting in more free plunging action. The slight increase (less than 1mm) in the back air chamber gives it yet more bass power and a slightly better sound.