Now if you'll excuse me I'm to wash the egg off my face.

Jim
gregbogantz wrote: I don't know for a fact what speed the latest Edison DDs and needle cuts were cut at, but I suspect that synchronous motors were used on the lathes simply because they produced consistent speeds that didn't need to be diddled with. The 78.260869 rpm speed is a direct result of using a 92-pole direct drive motor running on 60Hz mains power as done on some modern lathes such as the Neumann models of the 1970s.
You jest, surely.Edisone wrote:
78.26 is the speed at which a strobe disc will "stand still" under 60Hz light, that's why it was used. And I doubt that the Edison lathes used ANY electric motors - they still used the old weight-driven lathes, with new recording heads attached. Also, the amps would have been powered by storage batteries, not electric light current.
Wolfe wrote:You jest, surely.Edisone wrote:
78.26 is the speed at which a strobe disc will "stand still" under 60Hz light, that's why it was used. And I doubt that the Edison lathes used ANY electric motors - they still used the old weight-driven lathes, with new recording heads attached. Also, the amps would have been powered by storage batteries, not electric light current.
Mr. Electricity (by those days) used not only electric motors on his lathes, but everything else as well.
Edisone wrote:No, they absolutely did not use electric motors on the recording lathes, and neither did Victor or Columbia, and all 3 companies powered their amps with storage batteries. The same applies to Columbia, HMV, and other companies in England and Europe. There was no reason to replace the beautifully engineered & STEADY weight-driven motors, and electrical supply HUM was guaranteed to be recorded if they used AC mains current in the amps.
Wolfe wrote:You jest, surely.Edisone wrote:
78.26 is the speed at which a strobe disc will "stand still" under 60Hz light, that's why it was used. And I doubt that the Edison lathes used ANY electric motors - they still used the old weight-driven lathes, with new recording heads attached. Also, the amps would have been powered by storage batteries, not electric light current.
Mr. Electricity (by those days) used not only electric motors on his lathes, but everything else as well.
One can get that effect by running a mike cable next to a cable carrying AC power at 60hz. Goodness knows I've had to fight that battle a number of times in the past. It would be interesting to know what the Trinity sessions actually used.Viva-Tonal wrote:Yet at least the two recordings Victor made in the Trinity studio on 28 October 1925 released on blue label 45519 have considerable 60 Hz hum on them!