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Has anyone used glass instead of mica for victor exhibition or no2 reproducer? Wonder if the sound might be better

Jonsheff wrote: Tue Oct 12, 2021 10:59 pm .
Has anyone used glass instead of mica for victor exhibition or no2 reproducer? Wonder if the sound might be better

Interesting. But wouldn’t it add a little extra weight? I think it would Interesting if something like the Truetone diaphragm was made for disc machines!

Following the advice of Iñigo, our forum companion who actually did that, I bought a pair of glass diaphragms to try out on the exhibition, but did not have the time to install them yet. There is no weight issue, the glass is extremely thin and lighter than the mica, but as it does not have a hole the needle stem would need to be glued to the glass instead of screwed.

I recall a YouTube video of an EMG gramophone with a glass diaphragm - I think it belonged to Wyatt Markus at the time. I am trying to find the video...

Interesting... If it is on yt out could be looked for...

BassetHoundTrio wrote: Wed Oct 13, 2021 6:44 am I recall a YouTube video of an EMG gramophone with a glass diaphragm - I think it belonged to Wyatt Markus at the time. I am trying to find the video...

Is this it?
Bob

https://www.youtube.com/watch?v=lf5otGAbE9M

Wyatt messed around with this.He said it really improved fidelity.

Not to be a killjoy here, but countless hours were spent originally by the manufacturers experimenting with different materials to find the most practical material to make the diaphragms out of and a high grade of Mica was chosen to work the best under the circumstances. Edison and Columbia used glass diaphragms early on and it worked well when the early records were so poorly recorded and wore out but having restored a thousand or so early reproducers, finding an original reproducer where the diaphragm hasn't broken is quite rare. Those old glass diaphragms were always breaking and so too they would if installed on an exhibition or No.2, etc. Personally, I like to restore the original equipment to it's optimum working capability so as to enjoy what it sounded like at the time of manufacture rather than trying to modify what was made in order to extract better performance. My thought is use modern(Hi-fi,stereo) equipment if you want to hear better sound out of the old recordings

edisonclassm wrote: Wed Oct 13, 2021 10:02 am Not to be a killjoy here, but countless hours were spent originally by the manufacturers experimenting with different materials to find the most practical material to make the diaphragms out of and a high grade of Mica was chosen to work the best under the circumstances. Edison and Columbia used glass diaphragms early on and it worked well when the early records were so poorly recorded and wore out but having restored a thousand or so early reproducers, finding an original reproducer where the diaphragm hasn't broken is quite rare. Those old glass diaphragms were always breaking and so too they would if installed on an exhibition or No.2, etc. Personally, I like to restore the original equipment to it's optimum working capability so as to enjoy what it sounded like at the time of manufacture rather than trying to modify what was made in order to extract better performance. My thought is use modern(Hi-fi,stereo) equipment if you want to hear better sound out of the old recordings

When I was a kid, I experimented around with all sorts of different materials, I found one of the best sounding diaphragms was made of cardboard from a Shreddies box, I put the shiny ink side towards the horn.

Manufacturers may have spent countless hours with different materials, and I'll say design's, but just because they did, I don't believe it's the end-all beat-all solution to anything.
I think you used the key word there, "practical", using something as fragile a glass isn't practical, even if it may have sounded better.

Taking the chance that Carlos has given, I can talk about it.
I am trying this on the tabletop hornless hmv style 3, which is like a Victrola vi, the largest machine I have with exhibition soundbox.
The sound is noticeably clearer than with the mica, and I've tested this with the same record and needle, switching soundboxes (the original of the machine and the modified one). It is a subtle change, but noticeable of you pay attention and have good ears... The modifications on the exhibition are described elsewhere in the forum, but basically are 4:
1) glass diaphragm. The needlebar is attached with glue.
2) new back connector of Wyatt Marcus, micamonster.
3) new supple rubber gaskets; they're good, but yet I have to install newer ones of supple silicone rubber, also from Wyatt.
4) a handmade adaptor (demi-elbow) to correct tracking alignment
I don't know the reasons for sounding a bit clearer. My mica is good and clinks well, but I suppose the glass may be lighter and more stiff. This per-se would improve reproduction of higher notes, although I still don't master the technical side of the balance springs, which dampen the vibration before reaching the diaphragm, which is a major factor in sound. Yet I have to try modifying these, replacing thinner springs to see the effect. The small horn of this machine doesn't, though, allow for much quality... Adjustment of those needlebar springs is a complex matter, and I don't understand them very well yet. Besides that, the quality of acoustic recordings varies enormously from one label to another, so I always find certain records sound very well, but others sound tinny and unpleasant. And vocal records sound better with one adjustment, but orchestral or band records with another...
Besides that I tried another modification, which is to relax the pressure on the diaphragm edge and increase the air chamber by simply loosening the three screws at the back, letting the rubber gaskets to exert the minimum pressure while staying airtight. This increases the bass response, but with that horn it is almost not an improvement. With these adjustments and a thin needle, electrical records sound better, but not so much the acoustical ones...
Still learning...
Yet I have to try these exhibitions on my Vocalion, which has a larger and longer horn...