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Re: EMG/Expert/Astra/Wild/Meltrope soundbox weights.

Posted: Wed Jan 31, 2018 6:15 pm
by chunnybh
Interestingly both my Astra soundboxes weigh 204g.
That's the Astra 5 (No Meltrope Clamp) and the Astra 6 (with Meltrope Clamp).
My guess is, whoever built the Astra soundboxes also built the EMG soundboxes.

Re: EMG/Expert/Astra/Wild/Meltrope soundbox weights.

Posted: Fri Feb 02, 2018 10:59 am
by old country chemist
Hello Graham and all of you, I have weighed my two "OVERSTALL" SOUNDBOXES and have the following weights, of which I was rather surprised to see.
TWO SPRING OVERSTALL 187 GRAMS.
four spring pverstall 250GMS
Yes, I was rather surprised at the two weights. I always thought the 2 spring felt heavier! George Overstall did have his own design weight adjuster, and used to show folks who were interested, that he could bring the weight on the record to ONE GRAM!and play a Long Playing record with a fine bamboo needle.
I did read years ago that those who used tri-angular bamboo needles, should use a heavy soundbox, as the weight compacted the bamboo point into a hard ball. I must admit that I also prefer a heavier weight using fibre and bamboo needles, as I found when playing heavily recorded gramophone records using a weight adjuster, bringing the weight down to under four ounces, that on heavily modulated grooves, the needle would sometimes skip a groove or two, and the point would need resharpening. I know some of the EMG and Expert chaps use weight adjusters with great effect. I only really use one if I have to play a worn record that I know would break a point quickly
I am sending pictures of both soundbioxes

Re: EMG/Expert/Astra/Wild/Meltrope soundbox weights.

Posted: Fri Feb 02, 2018 11:02 am
by old country chemist
here is a picture of the two spring box.
Alastair Murray

Re: EMG/Expert/Astra/Wild/Meltrope soundbox weights.

Posted: Sat Feb 03, 2018 7:19 pm
by emgcr
Many thanks Alastair for sight of these fascinating, well made and extremely rare Overstall soundboxes. I can quite see that use of a weight adjuster might be necessary with the four-spring which is 10% heavier than the large Expert four-spring. Personally, I find a weight adjuster a little cumbersome for everyday use and seem to get consistently good results from the large EMG two-spring.

Re: EMG/Expert/Astra/Wild/Meltrope soundbox weights.

Posted: Mon Feb 12, 2018 7:35 pm
by emgcr
chunnybh wrote:
That's the Astra 5 (No Meltrope Clamp) and the Astra 6 (with Meltrope Clamp).
My guess is, whoever built the Astra soundboxes also built the EMG soundboxes.
I am sure you are right about the same manufacturer being responsible for all soundboxes in the EMG and Astra stables. As far as I know, Astras were made for the Gramophone Exchange but do we know what Numbers 1,2,3,4 look like ?

Re: EMG/Expert/Astra/Wild/Meltrope soundbox weights.

Posted: Tue Feb 13, 2018 4:36 am
by chunnybh
Referring to a previous post on the Astra 5. There is an ad here for the Astra 4 and refers to the Astra 2 being sold for half the price. I cannot remember seeing any info on the Astra 1, 2 & 3, but being pre-1924 they may well have been advertised in The Soundwave magazine.

http://forum.talkingmachine.info/viewto ... 11&t=18634

A few pics of the Astra 4 on the net. I believe it was available in mica diaphragm and with a "Specially built - up Composite Silk diaphragm".

Re: EMG/Expert/Astra/Wild/Meltrope soundbox weights.

Posted: Wed Feb 14, 2018 1:54 am
by Lucius1958
chunnybh wrote:Referring to a previous post on the Astra 5. There is an ad here for the Astra 4 and refers to the Astra 2 being sold for half the price. I cannot remember seeing any info on the Astra 1, 2 & 3, but being pre-1924 they may well have been advertised in The Soundwave magazine.

http://forum.talkingmachine.info/viewto ... 11&t=18634

A few pics of the Astra 4 on the net. I believe it was available in mica diaphragm and with a "Specially built - up Composite Silk diaphragm".
Interesting: why is the price shown as 42/-, when it could have been 2/2/-, or even 2Gn?
Bill

Re: EMG/Expert/Astra/Wild/Meltrope soundbox weights.

Posted: Wed Feb 14, 2018 8:55 pm
by chunnybh
Interesting: why is the price shown as 42/-, when it could have been 2/2/-, or even 2Gn?
Bill
Good point. I believe people generally dealt in shillings(a bob)rather than pounds. Average wage in 1930 was £165 a year. So spending 2 pound 2 shillings on a soundbox was pretty extravagant.

Re: EMG/Expert/Astra/Wild/Meltrope soundbox weights.

Posted: Wed Feb 21, 2018 5:27 pm
by Orchorsol
I was re-reading EMG's Book of the Fibre Needle yesterday (attached) and had forgotten that they found a heavier soundbox beneficial for the largest horns - an interesting finding, and one that seems to make scientific sense. If a large exponential horn such as the Xb Oversize couples more air, more efficiently, and to a lower frequency cutoff (also considering the additional energy requird to move the air at such frequencies), the needle must "see" a greater mechanical impedance, or put another way, must have to do more work.

Re: EMG/Expert/Astra/Wild/Meltrope soundbox weights.

Posted: Fri Feb 23, 2018 11:15 am
by old country chemist
THANK YOU "Orchorsol" for very kindly placing on the forum the download of the H.B. Davey booklet on how to use Fibre needles. etc. I had not seen that edition nefore. Fascinating reading-I wonder what a newcomer would think on reading the booklet! Mr Ginn advocated in one of his booklets,up to eight ounces bearing down on the tri-angular needle point. Basically, the weight compacted the needle point into a hard ball,suitable for reproduction, and most important, to alleviate fibre needle breakdowns. The heavily modulated grooves of 1930s onwards 78s required a reproducer to hold it's own in the wavy line of reproduction. I still prefer thorns, as they are easy to sharpen and seem to last the course better than the tri-angular fibre, and have a "cleaner" sound.
Thanks again for posting the booklet. I did enjoy reading it.