Re: [ARSCLIST] ET groove cutting ( was "More about ET preservation", was "Comparable collections anywhere?")

[Eric Jacobs <ericj@xxxxxxxxxxxxxxxxxxx>]

Hi Graham,

Thanks so much for the kind words.

I stare at ET grooves all day it seems through a microscope, and I've
noticed that some of the groove bottoms are sometimes not as smooth as
others - there will be parallel striations, or in some cases the walls
look smooth but the bottom is very rough, almost jagged.  At first I
thought perhaps this was groove wear, but the more I think about it and
see actual groove wear, I now think it's a poorly cut groove, like the
cutter wasn't hot enough or was cutting too deep or was perhaps dull or
mis-shapen or at the wrong angle...  I can look at and measure a groove
now and pretty much know in advance how much noise I can expect from
each stylus.  It would be nice to better understand WHY the grooves look
the way they do.

Since you've actually cut discs (wow, that is SO cool), can you shed
some insight into what phenomenon I might be seeing?  I'd like to be
able to classify groove condition more accurately in the technical
metadata, including poorly cut grooves (if that is indeed the case).

Eric Jacobs
Principal

The Audio Archive
tel: 408.221.2128
fax: 408.549.9867
mailto:EricJ@xxxxxxxxxxxxxxxxxxx


-----Original Message-----
From: Graham Newton [mailto:gn@xxxxxxxxxxxxxxxxxxxxx]
Sent: Wednesday, September 13, 2006 6:13 AM
To: ARSCLIST@xxxxxxxxxxxx
Cc: ericj@xxxxxxxxxxxxxxxxxxx
Subject: Re: [ARSCLIST] More about ET preservation (was "Comparable
collections anywhere?")


Eric Jacobs wrote:

> There are three things that affect the condition of ETs:
<HUGE snip!>

Eric has written a very good outline of the problems and considerations
needed
when handling and transferring lacquer coated discs in general and of any
size,
not just "ET's" (Electrical Transcriptions).

For those of us who lived the era of their use, most of the problems were
obvious, but none of us expected the deterioration and decomposition that is
being encountered today.

I actually cut 16" lacquers, as well as thousands of LP masters while I
worked
for RCA Victor in the early 1960's... a long time ago in a galaxy far, far
away, and yes, it was a great adventure!




... Graham Newton

--
Audio Restoration by Graham Newton, http://www.audio-restoration.com
World class professional services applied to tape or phonograph records for
consumers and re-releases, featuring CEDAR's new CAMBRIDGE processes.