The Talking Machine Forum — For All Antique Phonographs & Recordings

JohnM wrote:DDs are thick to ensure absolute flatness due to the vertical modulation of the groove,

So they wouldn't warp, I have heard that before.

I've also never heard or seen a warped DD, but I don't imagine a mild warp in one would cause too much problem, in the way of a much smaller diameter cylinder being out of round and causing severe and irritating pitch fluctuations. However, a very warped DD could present a problem to an actual Diamond Disc phonograph, I imagine.

I've got 2 or 3 vertical Pathé's that are mildly warped, but still quite listenable.

So let's say someone played a very noticeably warped DD on an Edison machine, could it cause actual damage to the record or the stylus? Or would it just result in pitch fluctuation, or some other audible problem?

You could easily kill a DD that's warped on a DD machine. The limit pin and height of the reproducer are such that a dished DD would get gouged by the stylus if it was hitting the top of the limit pin. I have seen lots of DDs that have dished, especially the earlier ones, for some reason. You can still play them on an Edison machine, but you have to lift up the lever a bit so the stylus doesn't dig up the disc.

Sean

frenchmarky wrote:What am I doing wrong, I tried the video here and in Youtube and just get a message that the video is private, I can't play it. Thanks

Same problem here.

Possibly the poster got deluged with outraged remarks from actual collectors, and, so to speak, took his marbles and went home.......

Wolfe wrote:

JohnM wrote:DDs are thick to ensure absolute flatness due to the vertical modulation of the groove,

So they wouldn't warp, I have heard that before.

I've also never heard or seen a warped DD, but I don't imagine a mild warp in one would cause too much problem, in the way of a much smaller diameter cylinder being out of round and causing severe and irritating pitch fluctuations. However, a very warped DD could present a problem to an actual Diamond Disc phonograph, I imagine.

I've got 2 or 3 vertical Pathé's that are mildly warped, but still quite listenable.

the thing is with the larger diameter Pathé's a lot of then are off center and of uneven thickness (so lefty-righty & upy-downy at the same time!)no problem on the original machines but try digitizing them its a real irritation factor when your pickup arm starts dancing all over the 16'' disc

i do them with a elongated pickup arm w preamp at 45rpm then it tracks fine i then speed the file up in the pc

greetings
tino

According to an Edison advertisement in the May 1927 issue of Popular Science Monthly , entitled ....."And now Thomas A Edison answers another questionnaire".......Concerning overtones...Ques. How have you captured these delicate overtones? Answ " In many ways . For example, I have made a thicker record of greater solidity which would not shake and vibrate as a whole when played . I developed an extremely hard and smooth surface for the record so that the sound waves---- the minute ones which are overtones---would not be flattened out when the diamond point passed over them . By adopting a permanent diamond point I got away from making the sound groves "grind in" steel needles. By mechanically feeding the so called tone arm across the record I eliminated having the delicate sound grooves drag the arm across..In other words I don't use delicate overtones to move machinery "...........This advertisement was presented as if Thom was in the room answering your questions , so these aren't my opinions , it's the word of god!!!