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 Post subject: Replacing mica diaphragms with aluminum
PostPosted: Fri Aug 02, 2019 12:14 pm 
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Victor IV
Joined: Sat Jul 09, 2016 7:12 pm
Posts: 1553
Don't know if there's any interest in this sort of thing, but I spotted this today --

Attachment:
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SEE: https://www.youtube.com/watch?v=KI5dBcDRjnM

It sounds great to my ears--full bass, clear treble.

I've often wondered what a Vic #2 sound box would sound like with an aluminum diaphragm, carefully dampened with the fulcrum adjusted for maximum resistance and maximum compliance. Has anyone ever tried this?

OrthoFan


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 Post subject: Re: Replacing mica diaphragms with aluminum
PostPosted: Sun Aug 04, 2019 10:41 am 
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Victor IV
Joined: Sat Jul 09, 2016 7:12 pm
Posts: 1553
OrthoFan wrote:
Has anyone ever tried this?


...apparently not.... :|


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 Post subject: Re: Replacing mica diaphragms with aluminum
PostPosted: Sun Aug 04, 2019 12:29 pm 
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Victor III
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Yes, but with mixed results - the best was with a generic European "Magnet" type soundbox on a frankenphone machine with a large morning glory horn (which I used to take out and about and play all day at various events) and it sounds really good, a stunning improvement, relatively speaking. The same mod with another soundbox didn't give any discernible benefit. Very hit-and-miss I guess.
BCN thorn needles made to the original 1920s specifications
www.burmesecolourneedles.com


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 Post subject: Re: Replacing mica diaphragms with aluminum
PostPosted: Sun Aug 04, 2019 1:26 pm 
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Victor IV
Joined: Wed Jan 07, 2009 8:44 pm
Posts: 1549
I agree that overall the sound is quite good. I just got my Orthophonic back from having some work done on it.. Only I am using the smaller portable of the period. I was impressed with the depth of sound so long as the music wasn't overwhelming to the reproducer. In the loudest of the symphony section the sound got a bit garbled but that may also be a problem of the early electrical process. I find the red seals for some reason have more sound issues than the ones produced in churches or their own hall. Mostly by the Victor Orchestra. In this case judging is a bit difficult because that size of horn puts out some amazing bass that one will not hear on normal sized horns. I had a couple metal reproducers and often the sound wasn't quite as good as the mica if it were in good shape.


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 Post subject: Re: Replacing mica diaphragms with aluminum
PostPosted: Wed Aug 07, 2019 1:02 pm 
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Victor IV
Joined: Sat Jul 09, 2016 7:12 pm
Posts: 1553
Orchorsol wrote:
Yes, but with mixed results - the best was with a generic European "Magnet" type soundbox on a frankenphone machine with a large morning glory horn (which I used to take out and about and play all day at various events) and it sounds really good, a stunning improvement, relatively speaking. The same mod with another soundbox didn't give any discernible benefit. Very hit-and-miss I guess.

larryh wrote:
I agree that overall the sound is quite good. I just got my Orthophonic back from having some work done on it.. Only I am using the smaller portable of the period. I was impressed with the depth of sound so long as the music wasn't overwhelming to the reproducer. In the loudest of the symphony section the sound got a bit garbled but that may also be a problem of the early electrical process. I find the red seals for some reason have more sound issues than the ones produced in churches or their own hall. Mostly by the Victor Orchestra. In this case judging is a bit difficult because that size of horn puts out some amazing bass that one will not hear on normal sized horns. I had a couple metal reproducers and often the sound wasn't quite as good as the mica if it were in good shape.


Many thanks for your input. Over the years, I've done some experimenting, replacing mica diaphragms with other materials--but not aluminum--with mixed results.

I agree, Larry, that the horn used in the video has a lot to do with the enhanced sound quality. It would be interesting to hear the same sound box used on an HMV 101 portable, or another gramophone that used that sound box, in comparison to a (restored) #4 sound box fitted with the original mica diaphragm.

BTW, I've also noticed a garbled quality in the louder passages on some early electric orchestral recordings. While this may be have resulted from the recording process, itself, in some cases I've been able to attribute this to groove wear, which is easy to spot if you inspect the record under direct sunlight. Whether the wear was caused by a worn needle, or if the record was damaged because it was played on a pre-1925 Victrola*** or one with a damaged or frozen sound box, is anyone's guess.

OrthoFan

***(I've concluded that after the switch to electrical recording, the vast majority of of pre-1925 phonograph owners continued to play their records on their older style models without any attempt to modify or upgrade them with improved reproducers, etc.--as surviving examples confirm.)


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 Post subject: Re: Replacing mica diaphragms with aluminum
PostPosted: Thu Aug 08, 2019 7:07 pm 
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Victor III
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Keep'em well oiled
Joined: Mon Dec 18, 2017 2:51 am
Posts: 517
Location: Madrid, Spain
Interesting. I've also done aluminium diaphragms by hand, and tried them on a Meltrope III soundbox, but the sound was not very good. I think my first trials were too thick. I keep other thin aluminium sheets to continue experiments, and I've thought about a Juwell Electro soundbox I have, which is a German version of the hmv no4, but with larger diameter. Very interesting.
Inigo


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 Post subject: Re: Replacing mica diaphragms with aluminum
PostPosted: Fri Aug 09, 2019 7:16 am 
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Victor IV
Joined: Wed Jan 07, 2009 8:44 pm
Posts: 1549
I should have said the metal diaphragms that are strictly flat in design like a mica one would look. Those to me generally didn't have the same quality as the mica. However the improved pressed designs like the Ortho and Viva Tonal, Brunswick type machines are improvements to the mica. I never found that the Victor 4 mica could live up to expectations for better sound like the 101 and other late acoustic machines with mica. However in direct comparisons between a mica and later style aluminum type the metal versions usually if not always won. They don't have as restricted a peak as the mica has.

On the topic of the sound of the classical symphony records on red seal, I believe they were recorded in some churches which may have proved difficult to get a clean sound in the loud passages. If you play some good Victor Symphony selections which were recorded in house you will find a much fuller without the same fuzzy effects on loud full passages. I recall the first time I heard a recording by the Victor Orthophonic, I was immediately struck by how clean the sound was compared to the Red Seals.


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