Shure M78S

3 minute wonder
Bob Dillon
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Re: Shure M78S

Post by Bob Dillon » 05 Mar 2019 18:16

Bob Dillon wrote:
04 Mar 2019 22:33
Exception would be a pantograph system, which sounds a little like what you are trying to describe. Pantograph systems weren't employed that much overall, except for dubbing purposes in the very early cylinder era, before the invention of master molds to mass produce cylinders. And again by Edison in the late cylinder era (post 1914 or so) to dub Blue Amberol cylinders from Diamond Discs, the Diamond Disc by that time being the dominant format produced by Edison.

I shouldn't have said that Edison Blue Amberol cylinders were pantographed, they were dubbed acoustically. I guess I had a little fog from too much blathering / typing.

AudioFeline
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Re: Shure M78S

Post by AudioFeline » 10 Mar 2019 01:31

jgifford25 wrote:
15 Jan 2016 02:36
...Also picked up one of those Spin Clean Record Washers which did a great job of removing 70+ years worth of who know what from the grooves....
I hope the cleaning fluid you used with the Spin Clean didn't contain alcohol. Alcohol dissolves shellac and should never touch 78's. If the cleaning fluid did contain alcohol you may had added noise to the disks.

AudioFeline
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Re: Shure M78S

Post by AudioFeline » 10 Mar 2019 01:36

Image of the rear of the Shure M78, showing a "strap" connecting the bottom two pins:

https://http2.mlstatic.com/shure-capsul ... 018-F.webp

Bob Dillon
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Re: Shure M78S

Post by Bob Dillon » 10 Mar 2019 01:52

Spin Clean detergent is alcohol free and said to be safe with shellac 78's.

You can use 91 % isopropyl alcohol to clean Edison Diamond Discs, which should not be exposed to water at all. An Edison DD wouldn't fit in a Spin Clean anyway. :P
jgifford25 wrote:
15 Jan 2016 02:36

Also picked up one of those Spin Clean Record Washers which did a great job of removing 70+ years worth of who know what from the grooves. After the cleaning, I've now got a few of these guys with some fractures in the shellac which means they're almost done for. W
'Fractures' could mean a couple things. 1, you have a solid shellac record that has cracked. 2, you have a laminated record, like a laminated Columbia, that has cracked on the surface, otherwise known as a 'lamination crack'. Such records should also not be exposed to water. If water seeps into the cardboard core of a laminated 78, it's probably a goner.

AudioFeline
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Re: Shure M78S

Post by AudioFeline » 10 Mar 2019 04:42

Bob Dillon wrote:
10 Mar 2019 01:52
Spin Clean detergent is alcohol free and said to be safe with shellac 78's...
Thanks, good to know.

Coffee Phil
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Re: Shure M78S

Post by Coffee Phil » 10 Mar 2019 05:32

Hi Bob Dillon,

It looks like I need you to “school” me on Coloumbia laminated 78s. I had thought that the inner core was the same sort of shellac mixture use in 78s of old for strenght while the playing surfaces had less clay filler to give less noise. I did not know about cardboard.

I also use 91% isopropyl alcohol to clean my Diamond Discs.

Phil
Bob Dillon wrote:
10 Mar 2019 01:52
Spin Clean detergent is alcohol free and said to be safe with shellac 78's.

You can use 91 % isopropyl alcohol to clean Edison Diamond Discs, which should not be exposed to water at all. An Edison DD wouldn't fit in a Spin Clean anyway. :P
jgifford25 wrote:
15 Jan 2016 02:36

Also picked up one of those Spin Clean Record Washers which did a great job of removing 70+ years worth of who know what from the grooves. After the cleaning, I've now got a few of these guys with some fractures in the shellac which means they're almost done for. W
'Fractures' could mean a couple things. 1, you have a solid shellac record that has cracked. 2, you have a laminated record, like a laminated Columbia, that has cracked on the surface, otherwise known as a 'lamination crack'. Such records should also not be exposed to water. If water seeps into the cardboard core of a laminated 78, it's probably a goner.

Bob Dillon
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Re: Shure M78S

Post by Bob Dillon » 10 Mar 2019 12:38

Well, maybe cardboard is an inaccurate term, with some of them a paper material was employed. I've seen some broken with edge chips that exposed the inner core. This goes into it somewhat. http://www.shellac.org/wams/wnewproc.html

An early patent for the laminated Columbia called for the use of a core of "earthy or other plastic materials".

In the 40's they promoted the laminate process on the record sleeves. There the core is simply identified as a '"coarse material".