The trick is not so much stylus size as shape.  The groove is U rather than 
V shaped.  A stylus is required formed so it does not get hung up on the 
shoulder of the groove since all the info is on the bottom.

An LP stylus, c. 1 mil, will usually clear and give decent but somewhat 
noisy vertical reproduction.  The more real estate the stylus encounters of 
the groove bottom without touching the shoulder, the better the 
signal-to-noise ratio.  This is true for cylinders as well.  Expert Stylus 
in England made these and may still do so.  They also made a doorknob-shaped 
one for the scalloped Pathe vertical groove.

I believe Mr. Eberle mispeaks below when citing Teddy Roosevelt on Edison 
discs.  I know only of cylinders by him from this manufacturer.  His discs 
are all laterally cut.

Steve Smolian

----- Original Message ----- 
From: "John Eberle" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Saturday, January 09, 2010 2:51 AM
Subject: Re: [ARSCLIST] Edison Discs

> Regarding stylii for playback of Edison Discs :
> The Edison factory  dimension spec for the stylus to play the 80 rpm
> Hill and Dale Diamond Discs  is .0047"   . So ; any smaller stylus , such
> as
> .003 " ,  made to play 78s will ride the bottom of the groove and not the
> sidewalls  resulting in less than optimum tracking of the modulation and
> degraded audio  playback .
> There are likely to be custom stylii manufacturers who could supply the
> proper size stylus for your
> favorite cartridge .  I prefer to use a meticulously maintained Edison
> C-250 Laboratory Model Phonograph to play and to re-record my Edison Discs
> .
> It is of interest that the Diamond Disc repertoire contains many gems
> by artists such as : Serge Rachmaninoff piano performances , Fletcher
> Henderson's Orchestra ,
> Vernon Dalhart of Prisoner's Song Fame , early country recordings by 
> Ernest
> V. Stoneman ,
> Fiddling Powers Family , Gene Austin & George Reneau and Cal Stewart (
> Uncle Josh ).
> Not to mention the US Marine Band , Billy Murray , Ada Jones  ,and 
> recorded
> speeches by
> Teddy Roosevelt and so much more .
> And the audio quality of these  recordings outstanding for their time ,
> check out the
> famous Edison Tone Tests where artists performed in public in direct
> comparison with their
> Edison Discs !
> There is a treasure trove of music and audio history available on Edison
> Diamond Discs and nowhere else .
> Just my 2 cents -  -  -   again .
> John Eberle
> 615-441-4660