Quote:
Originally Posted by Synchrodyne
Columbia chose the existing 33⅓ rev/min transcription speed for its LP. The readily available articles, such as that attached, do not explain why, although one may infer that the engineering analysis showed that there was no good reason not to do so. The full answer was probably provided in the article – which I have not seen - in the IRE Journal for 1949 August, available (for purchase) as an IEEE paper, at: https://ieeexplore.ieee.org/document/1698116, “The Columbia Long-Playing Microgroove Recording System”, by P. Goldmark et al. |
The Goldmark et al paper on the LP is in fact readily available at the American Radio History site, which has some of the IRE Proceedings issues, see:
https://www.americanradiohistory.com...roceedings.htm. The issue at interest is 1949 August. I have extracted and attached the article as a .pdf, heavily compressed, but still readable.
The reason for the 33⅓ rev/min rotational speed choice was not given explicitly, but one may derive from the initial conditions/constraints and the discussion on trades off that it was “in the ballpark”, if not precisely optimum. Thus we are left to conclude that Columbia found no good reason to deviate from this established speed. Not discussed in the paper, but the graphical data also show why 45 rev/min was a better choice for the 7-inch disc.
Cheers,