How Did Edison Dub Cylinders ?

[Marc Hildebrant]

Group,

I have searched the forum and somewhat on the internet regarding what specific technique did Edison use for dubbing the music on the 4 Min. cylinder records and so far no specific detailed info.

Most "quick" answers say that the Diamond Disc Horn was placed near the Cylinder recording horn. That may be true but it doesn't sound like a method that Edison would use as it's too simple. Has there been any pictures from the Edison Factory that shows the actual method used ?

Many of my cylinder records have the "needle drop" sound at the beginning and I know that they were dubbed, but I would believe that a famous inventor like Edison would have used much more elaborate method of dubbing than just putting the machines near each other ?

I have some records over number 5000 and even one around 5400 (Quite Knocking on the Jail House Door). They sound pretty good for a dubbed record.

Marc

[Wolfe]

Group,
I have some records over number 5000 and even one around 5400 (Quite Knocking on the Jail House Door). They sound pretty good for a dubbed record.

Marc

This is likely an electrical transfer / dub. Late BA's are not acoustically dubbed. It's taken from an electrically recorded DD from 1928.

Earlier on all I've ever seen is that from about 1915 BA's were acoustically dubbed from DD's, horn to horn. With the usual experimenting with refinements over time like optimizing matching the playback and recording heads, an adjustable damper between the horns to minimize blasting and so on.

[epigramophone]

I wonder whether Edison ever considered the pantograph method, which Pathé used to dub their vertical cut discs from large master cylinders.

[WDC]

There are some drawings in one of the two books by Ron Dethlefson in a chapter that deals with the dubbing subject. Basically, there were three generations of acoustic dubbing setups, and they were all horn-to-horn methods with different approaches of horn sizes and padding material put in between to lower those nasty resonances.

The last acoustic generation was a box or small sound chamber (size unknown, unfortunately) that both horns where connected to. That explains the more distanced and hollow sound of the mid-1920's BA's pretty well. I am sure they either used Edisonic or Dance reproducers for that, possibly even different diaphragms.

Btw. there had been plenty of experience with pantographs at Edison from the late 1890's but I am 100% confident that it wasn't a usable solution for several reasons. First, the groove pitch of a diamond disc is 150 tpi while a 4-minute cylinder is 200 tpi. Taking this into consideration would have required some considerable effort in designing a pantograph that could translate different groove pitches while staying aligned.
Also, the quality we all know from Pathé discs and cylinders shows the strong quality limitations of pantographs quite well up to the early 1920's with their lateral Actuelle label. It's always a very thin, almost tinny sound with little details and no dynamics left. I am sure, that Edison would have shivered by then to re-introduce this method to his recording business.

Edison himself had never been that fond of the Blue Amberol because it would always remind him of the Lambert patents that prevented him from using celluloid much earlier. The result of his attitude was obvious as he apparently did not even consider to rebuild the cylinder recording equipment after the 1914 fire that had started this awful dubbing in the first place. Another clue can be found in Edison's personal notes on recordings where he sometimes used to note, that a certain take was not to be issued as a diamond disc but "good enough" for cylinder. To me, that says a lot.

[52089]

Group,
I have some records over number 5000 and even one around 5400 (Quite Knocking on the Jail House Door). They sound pretty good for a dubbed record.

Marc

This is likely an electrical transfer / dub. Late BA's are not acoustically dubbed. It's taken from an electrically recorded DD from 1928.

Earlier on all I've ever seen is that from about 1915 BA's were acoustically dubbed from DD's, horn to horn. With the usual experimenting with refinements over time like optimizing matching the playback and recording heads, an adjustable damper between the horns to minimize blasting and so on.

It's generally accepted that BA's below 5650 were acoustically dubbed. At least some of those after 5650 were electrically dubbed, or an attempt was made to dub electrically. Documentation on this is pretty scarce and there are varying opinions on the subject.