Great question! I never added it up. But 78 came first. before the 
twinkling of 45 or 33.333, so that makes it even more mysterious.

Love to learn the lore!

Lou Judson • Intuitive Audio
415-883-2689

On May 24, 2006, at 12:16 PM, John Erdmann wrote:

> Hello Everyone,
>
> With regard to the three record speeds, is it just a coincidence that 
> 33 + 45 = 78?  Can anyone enlighten me as to the history and/or the 
> physics behind these choices?
>
> Thanks much,
> John