The Talking Machine Forum — For All Antique Phonographs & Recordings

The new Amberola V is playing many records with an incredible sense of reality & space - various instruments stand out as if they are completely separate from the rest of the group, yet still in the same room. Vocalists are right there at the edge of the horn, sharply apart from the orchestra behind them. I have this thought about it: that the shape of the V's horn, which is about 3 feet long & fairly narrow, accidentally approximates the shape of the recording horn used on many of the 1908-1914 Edison records. While not ideal for boosting bass response, it seems to me that this similar shape is reproducing vibrations very nearly the same way that they were captured - shooting them out with similar intensity & direction as received.

Thoughts? Any favorite machines which do the same?

I have noticed this too, and i think you are onto something. It is almost as if, even though they are "mono" recordings, there is stereo effect of placement of the instruments in the room, I do hear this on cylinders and diamond discs, but I guess I would have to listen to that Amberola V, I find this very interesting. The sound waves going down the horn, would be bouncing around in different planes, and then striking the diphragm in different places, not only is that stylus going up and down, there are slight side by side jostles. You think about it, the reproducing stylus could follow this. Many studio recorders had the cutting stylus suspended by two cords and a rubber back piece, the diaphragm floated in a gooey rubber mass, so this could happen.

edisonphonoworks wrote:I have noticed this too, and i think you are onto something. It is almost as if, even though they are "mono" recordings, there is stereo effect of placement of the instruments in the room, I do hear this on cylinders and diamond discs, but I guess I would have to listen to that Amberola V, I find this very interesting. The sound waves going down the horn, would be bouncing around in different planes, and then striking the diphragm in different places, not only is that stylus going up and down, there are slight side by side jostles. You think about it, the reproducing stylus could follow this. Many studio recorders had the cutting stylus suspended by two cords and a rubber back piece, the diaphragm floated in a gooey rubber mass, so this could happen.

I believe the "gooey rubber mass" would be a viscous damping substance. Not a liquid, nor a solid, but in-between. This is referenced in some texts on Edison. Which brings up the discussion, how can we as amateurs even approach the original recording quality in the Edison studios without access to the exact same recorders?

I have before encapsulated around the diaphragm with RTV blue silicone, and have used rubber cement too and flashed it with a torch, mica for the torch flamed one, and Victor, green album construction paper for the RTV silicon ones. The result was a really sensitive diaphragm, that seemed to act as a compressor on loud passages, that is it made soft and loud passages of equal volume, and not blast, recorded very low frequencies, like the boom of a Slick Rick rapper bass thud. I used the silicone, and paper diaphragm combination at Madison Square Garden at a session and was very surprised when I played it back electrically. This was all done to a regular Edison home recording body. Glass works very well with the silicone, or semi liquid rubber, and you get very low lows, and crisp highs. The problem with recorders made like this is, that they do not stay at the peak of performance very long, and get out of adjustment after a session or two.

edisonphonoworks wrote:I have before encapsulated around the diaphragm with RTV blue silicone, and have used rubber cement too and flashed it with a torch, mica for the torch flamed one, and Victor, green album construction paper for the RTV silicon ones. The result was a really sensitive diaphragm, that seemed to act as a compressor on loud passages, that is it made soft and loud passages of equal volume, and not blast, recorded very low frequencies, like the boom of a Slick Rick rapper bass thud. I used the silicone, and paper diaphragm combination at Madison Square Garden at a session and was very surprised when I played it back electrically. This was all done to a regular Edison home recording body. Glass works very well with the silicone, or semi liquid rubber, and you get very low lows, and crisp highs. The problem with recorders made like this is, that they do not stay at the peak of performance very long, and get out of adjustment after a session or two.

Another thing, besides viscous damping of the diaphragm, is that "Studio" recorders had an advance ball that rode on the wax blank and kept the recorder at a precise height above the wax, and had adjustments to change depth of cut.

" Another thing, besides viscous damping of the diaphragm, is that "Studio" recorders had an advance ball that rode on the wax blank and kept the recorder at a precise height above the wax, and had adjustments to change depth of cut. "

Sounds neat! Are there any existing pictures of this kind of stuff? I'm always fascinated by pictures of acoustic lathes - although they are few and far between.

There is a nice photo of one of Edison's master Phonographs on page 108 of Discovering Antique Phonographs by Fabrizio, Paul. There is also a nice article by Jerry Fabris in "In The Groove" April/May 2011 on page 40-49 so 9 pages on the studio recording and reproducing Phonographs. If you go to the restored laboratory in West Orange NJ, you will see much of this in person, along with a collection of the most wonderful recording horns, used to make Edison records, just think Billy Murray, Cal Stewart, Ada Jones,Collins and Harlan sang into them and into these Phonographs!!!!

Weird: It appears that one reason my V sounds so good is the Diamond B I borrowed from my D-X (the V's has a broken screw that needs to be replaced). The Diamond B off my Fireside has new gaskets & sounds okay, but this one is much better. I also just replaced a Diamond C's weird, homemade (by me, though I can't remember doing it) gaskets snipped out of some kinda super-rubbery stuff - they didn't even fit the inside diameter of the reproducer, but somehow I had them stuffed in anyway, and it really didn't sound too bad. New gaskets were an improvement, though.

Now, imagine my surprise when I looked at the "best" B and saw the same strange gaskets, poking out past the edge of the clamping ring! I don't know what this stuff was; a drive belt out of a VCR comes to mind, but I can't remember at all. They are too thick, so the clamping ring has to be screwed down VERY tightly to compress them & avoid screwing-up the stylus bar's angle. One would think that such a botch job would sound lousy and certainly not end up being by FAR the best of any Edison reproducer I've got. It probably cannot be duplicated - the C was 'eh', but the D is quite excellent, entirely by luck. I am going to leave it alone & enjoy.

Somebody should investigate synthetic, super-springy gasket materials.

Edisone wrote:Somebody should investigate synthetic, super-springy gasket materials.

I have pondered the making of flat gaskets from pure silicon caulk. I will describe one way I imagined doing so. I would lay some kind of ring on a glass plate and then pour paraffin wax into that mold to produce a block of wax at least ½" thick. Then mount that wax on a turntable or better yet, a lathe. Then turn the wax and use something like a screwdriver to carve a shallow square groove of even depth into the wax. This wax block is now the gasket mold. Squirt a generous amount of silicone into the wax mold and use a soft straight edge as a squeegee to remove the excess silicone. Once cured, the silicone gasket should be easy to pry from the wax. The wax mold might be damaged while prying it out, so you probably would have to prepare a wax mold for each gasket made. Perhaps a more permanent mold could be made from plastic or metal and used with some kind of release spray that won't contaminate the silicon.

I see now that this particular Diamond B has the underside of the diaphragm (the side open to the world) sealed with either shellac or rubber cement which has lost its stickiness. I also apparently reinforced the string linkage with a bit of shellac - I think that's what is boosting the volume. Edison ads boasted that their phono was made "for the home", meaning not "too loud". I swear the string serves mostly to reduce volume; I once tried replacing the wire link on a Model C with string (dental floss being the most handy) in various configurations - one piece with knots, a loop, a twisted loop, etc - and all it did was make the playback a little softer.

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