Origin of turntable speeds

[Netlist]

I seem to recall a post or even a thread explaining the origin of turntable speeds but can’t find it.
I’m particularly interested how 33 1/3 rpm and 45 rpm have become standards and if and how they are related to each other.
Does anyone remember?

/Hugo

 

[percival007]

Origin of Turntable Speeds.

Hi there,

see here for a pretty comprehensive explanation.

http://members.tripod.com/~Vinylville/spindoc.html

Cheers, Percy.

 

[Glowbug]

Those were the speeds the squirrels were trained to...

 

[hailteflon]

I recall reading more than once that the actual numerical rpm choices were the result of gear drives. Before the mid-40s the gear drive was common. 33, 45, and 78 are all whole integer gear ratios. I have never done the math. I assume that there was some sort of motor shaft/rpm standarad that they were stuck with.

33 rpm was already the standard for transcriptions and sound tracks. It is not the ideal speed for LP and has been a curse from day one due to the inner groove distortion.

Once again, I have never done the math. I read this. Mark