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 Post subject: Very loud soundbox needed.
PostPosted: Wed Mar 28, 2018 4:52 am 
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Victor III
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F. Depero, "Grammofono", 1923.
Joined: Thu Feb 24, 2011 4:19 am
Posts: 711
Location: Italy
Gentle fellows, as some of you may have possibly read in the past months, I am restoring a Gilbert portable. Despite being a fascinating machine, thanks to its eye catching trumpet-folded arm, I have unfortunately to admit that it's just not as good soundwise. Its original mother-of-pearl soundbox is of a very stiff type, and although having a (painted) aluminium diaphragm it behaves more similarly to mica soundboxes. Perhaps also because of the too short internal horn, the sound produced is unimpressive and, most of all, not very loud; consequently louder tone needles are required in order to achieve a satisfactory sound pressure, with increased record wear etc. As it is, this is not a gramophone that I would feel confident to use with all records, and would probably have very little use in my house.

I have also tried to attach to the arm a cheap off-brand aluminium soundbox, the only one I had at home with the 19mm collar adopted by Gilbert, but quite obviously the sound didn't improve significantly, as the cheap soundbox itself was nothing special to begin with.

I wonder if it would make sense to purchase a high-output and/or oversized, very sensitive, orthophonic-style soundbox that would compensate the poor behaviour of the machine at least to some degree. However, there is no soundbox that I know about which is as described, can anyone suggest a model perhaps? Ideally it should have the 19mm (exterior gauge) pipe connector adopted by Gilbert, but it's not strictly necessary as I can have a replacement back lathed by a specialised mechanic.

Should anyone have comments on this, I'd be very glad to read. I was so happy when I could finally purchase one of these machines, but now I'm so demotivated that even its restoration is languishing... :(


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 Post subject: Re: Very loud soundbox needed.
PostPosted: Wed Mar 28, 2018 5:39 am 
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Victor V
His epigrams are all his own, the man's an epigramophone!
Joined: Mon Oct 24, 2011 1:21 pm
Posts: 2174
Location: The Somerset Levels, UK.
The Meltrope soundbox in any version is probably the best all round performer this side of an EMG or Expert. They are not rare, and examples can usually be found on UK eBay.

Because the Meltrope attaches to the tonearm with a rubber coupling, available re-manufactured in various internal diameters, no machining or other modification should be necessary.

After WW2 Decca acquired the rights to the Meltrope and fitted it to many of their post war portables. When properly set up they have plenty of volume.


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 Post subject: Re: Very loud soundbox needed.
PostPosted: Wed Mar 28, 2018 6:26 am 
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Victor III
Joined: Sun May 27, 2012 2:38 pm
Posts: 629
Location: United Kingdom
Marco, I fear you have found out that Gilbert machines are not of the quality they pretend to be! Over the last twenty or thirty years, I've had various cabinet and portable machines from this Company through my hands, and can honestly say that I will never, ever buy another. The cabinet versions may sound a little better than the portables, due to their bigger horns, but the cabinets are, in 99% of cases, thin plywood nailed to the corner supports and covered with dark varnish to hide the grain of the plywood and the nail heads. The three portables I've had all sounded, as you have found, thin and lacking in bass response. I tried fitting an HMV No.5 to the last one I had, and if anything, the resulting sound was somewhat worse than that from the original Gilbert soundbox. I have also tried a Meltrope No.3, and although a bit better than the HMV, still not an improvement on the original. I'm sorry, but my opinion of Gilbert machines is that if you take away the fancy arm, what are you left with? The answer seems to be in most cases, a machine that you wouldn't look twice at if you were seeking a quality gramophone.


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 Post subject: Re: Very loud soundbox needed.
PostPosted: Wed Mar 28, 2018 8:35 am 
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Victor III
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F. Depero, "Grammofono", 1923.
Joined: Thu Feb 24, 2011 4:19 am
Posts: 711
Location: Italy
Indeed I suppose I had to come to terms with the low quality of Gilbert gramophones. But as long as I can live with a poorly manufactured cabinet, a machine with that spectacular arm that sounds so poorly is something that gets on my nerves. Also, the way in which the arm is joined to the shell, without bearings of any sort, is - in a word - pityful.

So, yes: what I am trying to do is to overcome the limitations of the machine in order to turn it in something worth being used. I dreamed for so long to own one of these machines, that now it's hard for me to give up on the dream.

At this point I don't know what to do with the hint of using a Meltrope. I have seen them mentioned very often on these pages, and thus I have frequently looked for them; in my modest experience they are not very common, actually they're pretty much rare. Also, according to Phono48, they won't do much to help the Gilbert. Is there one of Meltrope's models known among others for having an especially loud output?


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 Post subject: Re: Very loud soundbox needed.
PostPosted: Wed Mar 28, 2018 11:07 am 
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Victor III
Joined: Sun May 27, 2012 2:38 pm
Posts: 629
Location: United Kingdom
Marco Gilardetti wrote:
So, yes: what I am trying to do is to overcome the limitations of the machine in order to turn it in something worth being used.


With great respect, Marco, I feel this aim is something you will never be able to achieve. We have a saying over here which I think applies here. "You can't make a silk purse out of a pig's ear".As far as I know, all Meltrope soundboxes used a similar aluminium diaphragm, and none were any louder than the others. Your comments about the arm also ring true with my experiences. The whole weight of this massive arm has to be dragged across the record by the needle, resulting, in my view, in much accelerated wear to the records. To be fair, though, some of the arms did have bearings.


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 Post subject: Re: Very loud soundbox needed.
PostPosted: Wed Mar 28, 2018 12:20 pm 
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Victor IV
Joined: Mon May 13, 2013 2:04 pm
Posts: 1345
Marco Gilardetti wrote:
Gentle fellows, as some of you may have possibly read in the past months, I am restoring a Gilbert portable. Despite being a fascinating machine, thanks to its eye catching trumpet-folded arm, I have unfortunately to admit that it's just not as good soundwise. Its original mother-of-pearl soundbox is of a very stiff type, and although having a (painted) aluminium diaphragm it behaves more similarly to mica soundboxes. Perhaps also because of the too short internal horn, the sound produced is unimpressive and, most of all, not very loud; consequently louder tone needles are required in order to achieve a satisfactory sound pressure, with increased record wear etc. As it is, this is not a gramophone that I would feel confident to use with all records, and would probably have very little use in my house.

I have also tried to attach to the arm a cheap off-brand aluminium soundbox, the only one I had at home with the 19mm collar adopted by Gilbert, but quite obviously the sound didn't improve significantly, as the cheap soundbox itself was nothing special to begin with.

I wonder if it would make sense to purchase a high-output and/or oversized, very sensitive, orthophonic-style soundbox that would compensate the poor behaviour of the machine at least to some degree. However, there is no soundbox that I know about which is as described, can anyone suggest a model perhaps? Ideally it should have the 19mm (exterior gauge) pipe connector adopted by Gilbert, but it's not strictly necessary as I can have a replacement back lathed by a specialised mechanic.

Should anyone have comments on this, I'd be very glad to read. I was so happy when I could finally purchase one of these machines, but now I'm so demotivated that even its restoration is languishing... :(


Have you replaced the soundbox gaskets ? with age they can "glue" the diaphragm to the walls of the soundbox resulting in poor performance


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 Post subject: Re: Very loud soundbox needed.
PostPosted: Wed Mar 28, 2018 2:37 pm 
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Victor IV
Joined: Mon May 13, 2013 2:04 pm
Posts: 1345
"Regarding a loud soundbox. Yes I agree with "epigramophone, that Meltropes are first class. I feel than the no3 is perhaps the loudest-that is what I have found out.but I will say that in the 1970s I had a "Gilbert" soundbox, with an aluminium diaphragm, and a frontal guard with with "Gilbert" marked on it, and it was one of the best I have ever heard, loud, and the bass was excellent."

viewtopic.php?f=11&t=34814

Have you replaced the soundbox gaskets ? with age they can "glue" the diaphragm to the walls of the soundbox resulting in poor performance


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 Post subject: Re: Very loud soundbox needed.
PostPosted: Thu Mar 29, 2018 4:20 am 
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Victor III
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F. Depero, "Grammofono", 1923.
Joined: Thu Feb 24, 2011 4:19 am
Posts: 711
Location: Italy
Phono48 wrote:
With great respect, Marco, I feel this aim is something you will never be able to achieve.

I will not even try to argue against your arguments, as I basically agree with you and I think that this is probably a lost battle. Still, the dream of having a gramophone with a "trumpet" horn was so deep that I still think it's worth to give it a last try with some different soundbox.

@ soundgen: not only did I replace the gaskets, but I replaced them with a special type of super-soft brown tubing so kindly provided for free by CarlosV; unfortunately the difference was minimal if perceivable at all.


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 Post subject: Re: Very loud soundbox needed.
PostPosted: Sat Apr 07, 2018 12:49 am 
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Victor I
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Joined: Tue May 27, 2014 12:24 pm
Posts: 184
Phono48 wrote:
...We have a saying over here which I think applies here. "You can't make a silk purse out of a pig's ear". ...


As an aside, interesting how the language can diverge in different places. Here in the United States, I've always heard it as "You can't make a silk purse out of a sow's ear."

But perhaps there's still hope Marco can take the sow's ear and at least turn it into a well-tanned pigskin purse.


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