[Paul Stamler]

"Don Pearce" wrote in message
et...

Not a clue as to what could cause that, but at least you can safely
filter them off.

Well, fairly safely. There's signal on this disc at 8kHz, so I'll have to be
careful if I want to chop 10kHz. Probably use a noise-reduction program
rather than a straight filter, but we'll see. I'm more curious right now
about where it came from.

I suppose you need to start an investigation. Are they still there in
the lead-out groove.

Yes.

Are they there if you lift the stylus off.

No.

Are they
there on some other player - etc. At least you would know if they were
genuinely artefacts on the discs.

That, I couldn't tell you, because I only have one 78 turntable. But I
transferred several dozen discs for this project, all at roughly the same
time and under roughly similar conditions, and only the four Gennett sides
have this oddity.

As these were acoustic recordings I'm assuming that something was
squeaking in the clockwork mechanism prior to the speed governor and the
frequency reduction is a wind-down effect. Probably everyone in the room
was old enough that nobody could hear it as it started (high frequency).

Quite likely. Or perhaps it was entirely internal, and not audible from more
than an inch or two away.

Peace,
Paul