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Post by steverino on Oct 6, 2008 18:16:52 GMT
Some of the really cheap spider bridge instruments come from the factory with the perimeter of the cone screwed down. As the rims on these instruments are far from flat, the screws are a quick and dirty method to quiet any buzzing. They also kill the tone of course.
I have had good luck working the aluminum to straighten the outer edge of the cone and fit it to a newly flattened rim.
It is not unusual (though unnecessary) for the biscuit to be glued to the cone. Many early Nationals had the biscuit attached with hide glue and four small brads.
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Post by steverino on Oct 6, 2008 17:35:13 GMT
Why is it that whenever someone accomplishes something significant and wonderful, all sorts of trolls and other assorted mongrels will come out of the woodwork to try and tear him down? Happens in all walks of life. Having a forum such as this of course facilitates this.
Here are a few quotes taped to my office wall:
"The world belongs to the discontented." Oscar Wilde
"The higher we soar, the smaller we appear to those who cannot fly." F. W. Nietzsche
"Those who hear not the music think the dancers mad." Angela Monet
"If the Flintstones have taught us anything, it's that pelicans can be used to mix cement." Homer Simpson
Well, perhaps I should have stopped at three...
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Post by steverino on Sept 17, 2008 6:07:29 GMT
From what can be gleaned from Bob Brozman's book, John Dopyera was incensed that George Beauchamp claimed credit for inventing the single cone biscuit resonator guitar, hence the famous lawsuit. National had built John's single cone biscuit resonator into smaller instruments before the Dopyera brothers' departure from the company, though John had felt the tone of the single cone biscuit resonator was inadequate for guitar.
Decades later, OMI built biscuit resonators with quite nice looking compensated saddles; I have seen several of these go by on ebay.
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Post by steverino on Sept 17, 2008 5:43:05 GMT
I agree with tark on all counts. The slide forms a temporary termination of the speaking length of the string. The heavier the slide, the greater the impedance mismatch between string and slide. The higher this ratio, the slower the energy is lost to the termination point.
I have been experimenting with a thick wall machined steel tube section, an extension element for a screw jack device used to support a grand piano pinblock from underneath while the tuning pins are driven in from above . I polished up its exterior with some 1500 grit sandpaper. It enables noticeably longer sustain than the medium weight brass slide I had been using, though my hand becomes tired after a short period as it is quite heavy. The slow vibrato effects made possible by forcing the hand to control the heavy mass are interesting though, in addition to the long sustain.
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Post by steverino on Aug 3, 2008 0:51:26 GMT
Hi Michael,
The picture I have looks similar to the one you posted except that the base of the biscuit has the same diameter as the saddle. Jeff's cone looks as though it may have had this type of biscuit.
I'm not certain about this, but reading Bob Brozman's book leads me to believe that the lawsuit against Schireson was filed by George Beauchamp of National, likely after John and Rudy Dopyera had left to form Dobro. Three of John Dopyera's patents were part of the evidence presented to the court by Beauchamp. By the time the case was resolved, National and Dobro had merged as National Dobro Corporation and the Schireson assets became the property of that company, controlled of course by the Dopyeras.
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Post by steverino on Aug 2, 2008 1:27:12 GMT
I have a picture of some Schireson innards, taken off eBay a few months ago. I haven't figured out how to post pictures to the web, but will forward it as an attachment to Michael or Colin if you can provide me with an email address. I looked around here but struck out (easy, I'm kinda dense sometimes). I can be reached at stfrsc juno.com (install the @). The picture nicely shows the bowl shaped Schireson resonator, with a tall biscuit that reaches up from the cone apex to the string plane. I suspect that Jeff's may be this type, though it is difficult to tell the shape of his cone from the straight-on photo. There is a bit of discussion of Schireson resonators, with some positive comments on their sound, located here: www.guitarseminars.com/gs/viewtopic.php?t=263&postdays=0&postorder=asc&highlight=schireson&start=40
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Post by steverino on Jun 29, 2008 8:35:12 GMT
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Post by steverino on May 29, 2008 5:34:57 GMT
Phenolic resin is still used in large quantities in industry, usually impregnating some other material as has been discussed. Most often woven materials are saturated with the resin, which is partially cured then supplied to the customer for final curing in molds using a combination of pressure and heat. The impregnated cloth is referred to as "prepreg."
I investigated phenolics several years ago when I began a small loudspeaker manufacturing business. Phenolic has often been used in loudspeaker diaphragms due to its toughness and resistance to catching fire. This also makes it ideally suited for what I believe is still its largest industrial use, the forming of interior panels in commercial aircraft.
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Post by steverino on Apr 7, 2008 5:55:15 GMT
Bclaire, one interesting historical tidbit is that Jim Lansing's company, Lansing Manufacturing Company, was located at 6900 McKinley Avenue in south central Los Angeles from 1934 until after he sold the company in 1941. In the mid 1930s the Dobro factory was located at 6920 McKinley... right next door. Jim Lansing began spinning aluminum foil dome shaped diaphragms for compression driver theatre loudspeakers in 1935. I wonder from whom he might have learned the spinning technique?
I have an amplifier that was built by the Schireson Brothers in Los Angeles in the mid 1930s. It has a Lansing speaker that looks very much like the one in your amplifier. I can't comment on the value of your amp except to say that as a longtime collector lof Lansing's early work I think it's priceless! Thanks for posting the nice pictures.
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