Date:         Tue, 27 Jan 2004 22:45:15 -0500
Reply-To:     Association for Recorded Sound Discussion List
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Sender:       Association for Recorded Sound Discussion List
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From:         "Steven C. Barr" <[log in to unmask]>
Subject:      Re: Superior disc cleaning technology
Comments: To: Association for Recorded Sound Discussion List <[log in to unmask]>
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----- Original Message -----
From: "Ron Fial" <[log in to unmask]>

> Has anyone tell us what they mean by a 'clean' 78, or a 'cleaned' 78.
> It makes more sense to have a contest between machines after agreement
about how the 'clean-ness' of a 78 is measured.  I am no expert, but here
are some possible criteria, and I suppose you could give a numeric weight to
each measurement to come up with a cleaning 'score'.  I am sure there are
many other measures that could be taken, like actual signal to noise ratio
and the like.
>
> 1)  presence of dirt or microscopic metal particles in the groves.
>
> 2)  Lowest noise levels in a quiet section of grove.
>
> 3)  Lowest ionic contamination ( part of the 'cleaned' record is dipped
into distilled water and stirred.  Then the ohmic resistance of the water is
measured, the resistance will drop due to ionic contamination).
>
> 4)  The record after cleaning sounds better, has less distortion, less
residual noise in quiet parts of the grove.
>
> 5)  The record after cleaning has shinier surface.  This could be due to
dirt removal or actual surface
> polishing, but this could be due to residual oils or soaps also, which is
probably not a good result.

Of all of these, #4 is the only one which has any actual applicability! #2
is part of #4...#1 and #3
are of interest primarily to research chemists, unless any become catalysts
for the chemical breakdown
of shellac..and #5 can be easily simulated with a can of black Shinola!
Steven C. Barr