[Jukebox-list] Damage to needles playing 78s

[David Breneman]

--- Aaron Heverin <aaron at vertasource.com> wrote:

> With all of the 78s jukeboxes that we have, I think the general
> consensus is that when we restore or somewhat "modernize" the
> antique Wurlitzers, Seeburgs, and Rock-Olas - we replace the
> ancient 2 pound ceramic original cartridges with newer light-weight
> versions - such as the Astatic 51 series. 

Actually, these older cartridges were usually magnetic.
The large size and heavy weight were due to the use of
a horseshoe magnet wrapped around the moving coil to
produce the electric field.  The moving coil pickup is
actually the oldest electronic pickup technology still
in use.


> Would playing a record in this condition...or ANY other type of 78s
> that had a small crack, or some dings and other wear
> imperfections... do any damamge to the Astatic needles, or any
> other type of needle that is used to play back 78s?

Do these Astatic pickups have diamond or sapphire styli?
Obviously, a diamond stylus will last longer, but even with
sapphire, it's pretty hard for a record to damage a stylus.
Now, when you talk about the type of needles used back then,
then we're talking about steel needles.  A record does
damage a steel needle, and that's why a needle should be
discarded after *every* play.  The reason this is so is this.
When Berliner was developing his disk record, he had to
avoid infringing any of Edison's patents.  He needed a
record material that was strong and would tolerate the weight
of a reproducer *and* horn riding on it (tonearms came later),
since Edison had patented the concept of an articulated
stylus carrier connected to a reproducer drawn across the
surface of the record by a feed screw.  Berliner had to
come up with a record durable enough that the groove itself
could carry the whole reproduction apparatus unaided.

After several fits and starts, Berliner developed a record
made of shellac resin which used fiber and ground stone
filler for strength.  Since Edison held the patent for a
permanent jewel stylus, Berliner was pretty much stuck 
using a "sacrificial" steel needle to play his records.
The abrasive nature of the filler in the records would,
within a few playings, grind the tip of the needle down 
to where it would bounce around against the groove walls,
doing tremendous damage to the groove surface.  Ergo, the
admonition to change the neddle with every play.  As the
record wore, the shellac carrier resin would grind away from
the groove walls, exposing the fiberous filler, and that's
what predominantly gives worn 78s their grey appearance.

So, a steel needle *should* be worn down.  The cheap
needle is sacrificed to preserve the expensive record.

As time went on, jeweled styli were no longer protected
by patents and pickups became lighter, so the need for
the sacrificial steel needle disappeared, although they
were still used on cheap and kiddie phonographs into the
early 50s.  In the late 30s record companies began
reducing the amount of filler in records, and making
what remained finer grain, in response to the gentler
pickups.  This trend continued right on through the
demise of the 78, which is why you should never play
a record on a phonograph of an older generation than
the record itself (ie, playing Elvis on a Victrola is
strictly verboten).

So, no, a modern stylus should not be damaged by a
worn record, but any record *must* destroy a steel
needle to protect the record from the heavy pickup.


David Breneman         david_breneman at yahoo.com


 
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