Adding a long play mechanism to a Diamond Disc phonograph

[phonogfp]

Just to Add a note to this discussion.......Many Edison Diamond Disc Machines were sold with the 10" / 12" Buttons switch attached, but no 10" / 12" Long Play assembly installed. I guess Edison figured that the owner would get curious about the buttons that did literally absolutely nothing when you pressed them, then ask their Edison Dealer then to install the option. (I guess Phonograph Jobbers made House Calls in those days...lol.. ). - Tony K. Edison Collector/Restorer, Melbourne, Florida.

The problem with this theory is that the 10"/12" button appeared on machines several years before the LP equipment was offered.

George P.

[MrRom92]

Upon getting my invoice, I ended up winning one of the other 12” Long Plays in the catalog. Definitely not the Beethoven… but interesting enough.
I’m curious, do you know what the appropriate stylus would be to play this on more modern equipment?

Congrats! As to the stylus, I don't know; I'd consult with Expert Stylus in England.

I reached out to Expert Stylus Co. and just heard back, they suggested and offered a .0015" FCR diamond for Edison LP playback.
I’m actually surprised by this as I figured the incredibly fine groove of these records would be equivalent to microgroove or perhaps something even smaller

[Lucius1958]

Just to Add a note to this discussion.......Many Edison Diamond Disc Machines were sold with the 10" / 12" Buttons switch attached, but no 10" / 12" Long Play assembly installed. I guess Edison figured that the owner would get curious about the buttons that did literally absolutely nothing when you pressed them, then ask their Edison Dealer then to install the option. (I guess Phonograph Jobbers made House Calls in those days...lol.. ). - Tony K. Edison Collector/Restorer, Melbourne, Florida.

The problem with this theory is that the 10"/12" button appeared on machines several years before the LP equipment was offered.

George P.

Edison had envisioned 12" DDs since the outset; hence the phonographs were outfitted with 12" turntables. There was another attempt to revive the format around 1922; my very early BC-34 has the buttons.

- Bill

[phonogfp]

I reached out to Expert Stylus Co. and just heard back, they suggested and offered a .0015" FCR diamond for Edison LP playback.
I’m actually surprised by this as I figured the incredibly fine groove of these records would be equivalent to microgroove or perhaps something even smaller

I seem to recall reading in period Edison literature that the LPs were manufactured with 450 tpi.

George P.

[MrRom92]

I reached out to Expert Stylus Co. and just heard back, they suggested and offered a .0015" FCR diamond for Edison LP playback.
I’m actually surprised by this as I figured the incredibly fine groove of these records would be equivalent to microgroove or perhaps something even smaller

I seem to recall reading in period Edison literature that the LPs were manufactured with 450 tpi.

George P.

Yes, although this doesn’t necessarily correlate with a smaller groove dimension, it certainly suggests that one may have been used. The LPI of a typical modern LP is much lower than that, often by half or even less.

[JerryVan]

At 450 TPI, the groove width would be .002", which seems to correlate with the recommended .0015" stylus.