Glass Diaphragms For Exhibition Reproducers

[SonnyPhono]

Recently I was asked by Mike, (Boyle6) to rebuild an Exhibition reproducer that needed an overhaul. I would normally use a mica replacement diaphragm for the rebuild, however, I had been emailing back and forth with Jim, (Victor78) about a new glass diaphragm that he had recently used on one of his rebuilds. I offered to use one on Boyle6's rebuild and he was interested in hearing a glass diaphragm. I wasn't able to test the finish product as he picked it up before the glue was fully dry. (There is no hole in the center to attach the needle bar foot so it is instead glued or epoxied in place.) I received a call from Mike today and he was thrilled. He said it had the best and most clear sound reproduction of any Exhibition he had heard. He had tested one with mica and then switched to the glass and said there was a noticeable difference in clarity. I am going to rebuild another for him soon and when I do, will be sure to take some pictures to post here and will also check the decibel level with my docimeter.

I just wanted to post this thread to let everyone know about this option in case others would like to try one in their Exhibition. If interested, send a PM to Jim via his user name: Victor78. He can tell you the details as he has access to them.

Thanks for the new diaphragms Jim, and for all the help with installation instructions.

[Tinkerbell]

There was a seller on Ebay here in Wisconsin that had these glass diaphragms listed about a month or two ago. I was really curious about them, but without any knowledge or input, decided to take a pass.

I'm glad you brought this up; if the seller lists them again, I think I'll bite this time around.

Thanks for posting about this.

[Wolfe]

What are the odds of breakage from rough handling, or say, too much pressure on the diaphragm from a extra fat loud tone needle?

I've heard good things about glass replacements for Victrolas, and glass was used by Victor in their recording diaphragms (in the acoustical days) as well.

[frenchmarky]

What is the diameter of an Exhibition diaphragm? Thanks

[Tinkerbell]

What is the diameter of an Exhibition diaphragm? Thanks

1 23/32" according to the APSCO site.

[novkev24]

I would be interest in replacing the mica diaphragms in my no. 2 reproducers with glass. Does anyone know where I can purchase this item?

-Kevin

[Victor78]

Thanks Sonny for the kind words and I'm happy that you and Boyle are pleased with the diaphragms. I like them as well and have them on a few of my Exhibitions that I use regularly. The question was asked about breakage: Of course there is a chance that they will break if you were to drop the reproducer, but in actual playing, not at all. After I received a few from Norman, I did some testing with installation and usability. My big test was using a extra loud tone spade type needle, on my Victrola XVII and an electrically recorded disc. The results were amazing, and Loud! No distortion from the diaphragm at all, and a nice punch from band type records. There is a nice mellow tone on vocals, and an all around smoother response for a natural sound. Not all machines have the same results though as far as loudness. I tried on a Vic VI, and it wasn't any louder than normal, but the tone was better (mellow). I brought my demonstrator Exhibition along to Union this year, and if I remember right, we put it on a Vic V, outside in the back. And again, it wasn't any louder than a mica, but the tone was much nicer to listen to. But then we were outside with a lot of background noise as well. When I demo them at my house, I put it on different machines so people can hear the difference, and then play the same record with both mica and glass. Most can hear the difference and like it. It all comes down to how you 'hear' your music. Ive always been pretty picky on how my things sound, starting many years ago with home stereo equipment. I also used to do sound for a rock band in high school and the guys would always give me crap about having to tweak things when they though it sounded OK

At this time, there are only two versions of the glass diaphragms that I sell. One for the Exhibition, and the other for Edison reproducers. I have used them on my C and my H with good results. I'm currently writing up some instructions on how I install them in the Exhibitions. It takes some patience to get it just right, because after the glue dries, you cant 'undo' it easily. The first one I did I used epoxy, and then realized if It broke, I would probably have to use a Dremel tool to grind off the adhesive, so I started using super glue. It gives a good sturdy bond as well. To top it off, I melt a little wax over the super glue to hide the clouding on the glass, and to give it an original look. There arent any holes in the diaphragms so you dont need to use the tiny screw that normally holds the mica to the needle bar. Put it in a small zip lock bag in case you need it for future rebuilds. Sizes and other info are on my website if your interested.

There have been a couple of people that purchased since last night, thank you. When you have them installed, I would appreciate your feedback as Im sure Norman would like to hear your thoughts as well. In fact, I spoke with Norman this morning and he was surprised to see a thread about them

Jim

[frenchmarky]

Dang too bad they are only available for Victor Exhibitions, would be cool to try a larger one on my Victor #4 boxes, which have needle bearings. The loudness might go up noticeably on these since the needlebar doesn't have any resistance from springs like the Exhibition and #2. Even trying one on my old #2 would be neat.

Superglue sounds like the right thing to use, since if the bond eventually breaks you could just use acetone to dissolve it.

Are these glass ones the exact same thickness as regular mica diaphragms? Here's hoping larger sizes eventually become available.

[Victor78]

I too would be interested in see what they would be like on a #2. Maybe someday we'll find out, but as of right now, I dont believe there are any plans on making them in other sizes.

Im not sure what the thickness is, but they are not much thicker than the mica.

[SonnyPhono]

The glass diaphragm is about 50% thicker than the mica. They are .009" thick and the mica are .006". That may seem like a big difference, but we are talking thousandths of an inch. It seems that the difference is just enough to take off the needle noise and mellow everything down a bit.