[78-L] wet playing records

[Jeff Lichtman]

>But Michael Biel said, (and this is what surprised me), that the 
>water actually dissolves the shellac and causes more pits in the 
>groove walls and hence more noise, (if I understood him correctly).
>
>db

When you play a record wet the water is forced into the surface at 
high pressure. Records are slightly porous, and this pressure pushes 
the water into the pores. My guess is (and I really am hypothesizing 
here) that this causes tiny bits of the surface of the record to 
break off. Since the record is wet, these bits will mix with the 
water and be pushed along by the stylus as an abrasive slurry, 
causing even more record (and stylus) wear.

As for why a wet record might sound better - the water probably fills 
in the little pits caused by wear and by the record's filler 
material, causing the stylus to skate over them. I would expect, 
though, that the water would also fill in the small groove 
undulations caused by high-frequency signal, and would round the 
edges of transients. This again is the fundamental problem of noise 
reduction - how do you distinguish between signal and noise? Does 
playing a record wet do anything that a low-pass filter wouldn't do?


                        -        Jeff Lichtman
                                 jeff at swazoo.com
                                 Check out Swazoo Koolak's Web Jukebox at
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