On Wed, 4 Feb 2009 19:17:45 +0200, "Iain Churches"
wrote:


Don Pearce wrote in message news:4992beba.108434515@localhost...
I was interested in how heavily modulated vinyl could be, so I popped
an old record (Long Hot Summer Night, Jimi Hendrix, Track Records
1968) under the microscope for a look. And what did I find? Two
adjacent grooves clearly broken into each other:

http://81.174.169.10/odds/grooves.jpg

Was this a really common back then, or is this kind of thing a rarity?


Neither rare nor common.
It was normal practice to examine heavily modulated passages
under ther microscope after cutting both the test and the final
master. Many cutting engineers used to also test cut loud segments
with excessive lateral excursion several times as a practice run.

But it was impossible to check every single patch with the microscope.
The master was never played, but the initial test cut usually was. If
no problems were encountered with say an SME 3009 and Shure V15
then the master went to the factory.

Are there tracking problems with the Hendrix, Don?

Iain



No, not at all. I was just feeling a bit bored and curious. I thought
that even in '68 there was some automation that predicted amplitude
and widened the pitch a little.

d
--
Pearce Consulting
http://www.pearce.uk.com