Stupid idea - probably .........................

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poodling around
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Stupid idea - probably .........................

Post by poodling around »

I was thinking earlier about an HMV Exhibition Sound box / reproducer I have and how the rubber gasket has become solid, has shrunk and creates a buzzing noise when playing a loud record.

So, I started looking up how to dismantle it and replace the gasket. This seemed like a lot of hard work.

Then I thought, why not just place an external narrow ring of Blu-Tack around it - over where the old gasket is placed. This might stop the buzzing by placing renewed pressure on the diaphragm and sealing it.

It seemed to work as a remedy very well - improving the sound quality 'a lot' - no more buzzing for example.

Who knows, maybe the oils which leak from the Blu-Tack will also revitalize the old rubber gasket ?

Is this a really bad idea ? :(

HisMastersVoice
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Re: Stupid idea - probably .........................

Post by HisMastersVoice »

You aren’t going to get the best sound until both gaskets are replaced. It’s honestly not that much work, and it’s certainly not hard. I can do an exhibition in about 20 minutes or better. Any machine I get, I rebuild the soundbox immediately. Why settle for poor sound when it’s so easy to bring it back to factory specifications?

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poodling around
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Re: Stupid idea - probably .........................

Post by poodling around »

HisMastersVoice wrote:You aren’t going to get the best sound until both gaskets are replaced. It’s honestly not that much work, and it’s certainly not hard. I can do an exhibition in about 20 minutes or better. Any machine I get, I rebuild the soundbox immediately. Why settle for poor sound when it’s so easy to bring it back to factory specifications?

Thank you very much for your advice Brandon.

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Re: Stupid idea - probably .........................

Post by Jerry B. »

Your basic idea has merit when dealing with pot metal reproducers that are too scary for disassembly and rebuilding. You apply white glue (Elmer's) on your finger and sweep around the hard gasket. It will dry clear as well as making an improvement in sound. But it is a shortcut that is sometimes necessary.

Jerry B.

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poodling around
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Re: Stupid idea - probably .........................

Post by poodling around »

Jerry B. wrote:Your basic idea has merit when dealing with pot metal reproducers that are too scary for disassembly and rebuilding. You apply white glue (Elmer's) on your finger and sweep around the hard gasket. It will dry clear as well as making an improvement in sound. But it is a shortcut that is sometimes necessary.

Jerry B.
Ah. Thank you very much for your view and additional information Jerry B.

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Henry
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Re: Stupid idea - probably .........................

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poodling around
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Re: Stupid idea - probably .........................

Post by poodling around »

Thank you very much Henry.

A clear, very well written 'step by step' guidance page - your link is really appreciated.

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Marco Gilardetti
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Re: Stupid idea - probably .........................

Post by Marco Gilardetti »

poodling around wrote:It seemed to work as a remedy very well - improving the sound quality 'a lot' - no more buzzing for example.
All you did was dampening the buzz and rattle. You'd get a similar result just by keeping your fingers over the gaskets or the needlebar, touching them lightly while the soundbox plays. You avoid buzzing and rattling but the overall sound isn't really improved: the diaphragm will still not be airtight, it will still not move freely and the needle would scrape the grooves, and possibly, in the frequent case in which the dried up gaskets are also distorted, the needlebar will be misaligned and subject to spurious forces.

Only by replacing the old hardened gaskets with soft, airtight gaskets and by correctly aligning and adjusting the needlebar your gramophone will deploy all of its potential and will be kind with the grooves. We're not talking about sonic subtleties: if the machine is of good quality with a well engineered horn, the improvement will be outstanding and everybody will be able to tell it.

I also reckon, though, that this idea is better-than-nothing when dealing with soundboxes which are not to be opened. I would just use some material (silicone perhaps?) which is more neutral, stable and lasting than blue tack.

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poodling around
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Re: Stupid idea - probably .........................

Post by poodling around »

Marco Gilardetti wrote:
poodling around wrote:It seemed to work as a remedy very well - improving the sound quality 'a lot' - no more buzzing for example.
All you did was dampening the buzz and rattle. You'd get a similar result just by keeping your fingers over the gaskets or the needlebar, touching them lightly while the soundbox plays. You avoid buzzing and rattling but the overall sound isn't really improved: the diaphragm will still not be airtight, it will still not move freely and the needle would scrape the grooves, and possibly, in the frequent case in which the dried up gaskets are also distorted, the needlebar will be misaligned and subject to spurious forces.

Only by replacing the old hardened gaskets with soft, airtight gaskets and by correctly aligning and adjusting the needlebar your gramophone will deploy all of its potential and will be kind with the grooves. We're not talking about sonic subtleties: if the machine is of good quality with a well engineered horn, the improvement will be outstanding and everybody will be able to tell it.

I also reckon, though, that this idea is better-than-nothing when dealing with soundboxes which are not to be opened. I would just use some material (silicone perhaps?) which is more neutral, stable and lasting than blue tack.
Thank you very much Marco Gilardetti. I appreciate hearing your considered comments and suggested alternative course of action.

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AudioFeline
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Re: Stupid idea - probably .........................

Post by AudioFeline »

Blutack will become hard with age. But I agree with the above posts, best to replace a part rather than use a band-aid remedy that won't be as good and may do damage with age.

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