But 78 rpm is actually 78.26 rpm, so why is he using 77.92 rpm? That's
another 0.43% error.
From: Association for Recorded Sound Discussion List
[mailto:[log in to unmask]] On Behalf Of John Haley
Sent: Thursday, November 26, 2015 9:47 PM
To: [log in to unmask]
Subject: Re: [ARSCLIST] 78rpm replay speeds & pitch
Welcome to the wonderful world of 78's. That's just how it is. You have to
deal with each record as a thing to itself.
On Nov 26, 2015 6:22 PM, "Andrew Hallifax" <[log in to unmask]>
> I'm currently digitizing a series of Odeon 78 rpm discs of recordings
> made in the early 1950s of one particular ensemble and I'm surprised
> to find that while most discs render A=c440Hz when replayed at 78rpm
> (77,92) certain exceptional examples deviate by 2% or more. Can anyone
> suggest a likely cause? In some cases, discs ostensibly recorded on
> the same day whose two sides bear consecutive matrices, even differ
> from each other.
> More puzzling still are a couple of discs where the pitch drops
> gradually by around a quarter of a tone (roughly 3%) during playback
> of the side. If anyone can suggest the likely or possible cause of
> this, I'd be delighted to read about it.
> Many thanks