It appears to feed the back of the diaphragm case & may be setting a fixed back pressure to control the excursion of the diaphragm.
There are non-harmful tweaks that can be applied to the interior of the Victor Credenza that reduce the effects the restricted airspace places on the diaphragm. The results are quite audible & positive. Even more so when several non-standard adjustments are made to the reproducer pivots & tracking angles.
Most collectors frown on such non-harmful alterations but they afford an unexpected level of playback quality when paired with higher quality needles than readily available today. Under such conditions, thoroughly cleaned shellac discs offer a surprisingly long lifetime of quality playback.
On Oct 23, 2013, at 10:46 AM, Tom Fine wrote:
> Thanks for the links, Rob. Don't assume I (or other listmembers) know anything about the ancient times of sound recording. Never TMI about this stuff!
> Regarding this photo:
> Does that show an electric motor to drive the disk platter?
> Also, what is the funnel and what seems like a liquid container sticking out of the top for?
> This photo:
> described as the Berliner family singing into a Gramophone recorder in 1898, seems to show the same machine, from the other side.
> Thanks again for bringing these photos to our attention.
> -- Tom Fine
> ----- Original Message ----- From: "Rob DeLand" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Wednesday, October 23, 2013 11:06 AM
> Subject: Re: [ARSCLIST] Nellie Melba' 1st records
>> Tom, I assume you're familiar with the photos posted here:
>> Note items 11, 13 & 16 in particular for Berliner recording equipment.
>> On Wed, Oct 23, 2013 at 7:30 AM, Michael Quinn <[log in to unmask]>wrote:
>>> Hi Tom,
>>> I'll answer your queries as best I can -
>>> The Gramophone & Typewriter Company used pretty much the same
>>> equipment as Victor and by 1904 were well experienced recording on wax
>>> masters. The recording lathes used weight driven clockwork motors and
>>> continued to do so for many years. There are no photographs of Melba
>>> recording in 1904 but there are artists impressions published in
>>> periodicals of the time - I think the recording apparatus was behind a
>>> screen or curtain with a horn measuring about a foot across the mouth
>>> projecting out into a large room. Going by early photographs there
>>> must have been multiple recording horns even for the piano accompanied
>>> 2. I blundered in saying waxes - it was shells being taken to Hanover
>>> though waxes were often sent from various places in Europe to the
>>> factory in Hanover. With the Melba recordings being such a prestige
>>> item they did the initial processing in England. It was a not
>>> infrequent occurrence for wax masters to be broken in transit to the
>>> factory in the early days of European recording.
>>> 3.The waxes would have been quite thick but I don't know what kind of
>>> metal soap they were using to make the blanks.
>>> 4.The vinyl 78s allowing for the inevitable minor problems that come
>>> from age and conditions of storage are very good, They have a higher
>>> surface noise than the best later acoustic recordings but are forward
>>> and bright sounding and of course without the wear that is often so
>>> apparent on original G&Ts. The sense of presence is quite startling
>>> and I certainly now believe my grandfather who said Melba's was the
>>> most carrying voice that he ever heard in person.
>>> I don't know what caused the noise problems that worried the company
>>> types - perhaps to do with how hot or cold the waxes were at the time
>>> of recording.
>>> Best Wishes
>>> Mike Quinn
H D Goldman Lagniappe Chemicals Ltd.
PO Box 37066 St. Louis, MO 63141 USA
v/f 314 205 1388 [log in to unmask]