Jon, again, I have addressed some of these questions in earlier
missives. The ideal needle material for use with acoustic reproducers would
be a 5 mil diameter wire that is soft enough to conform quickly to the
groove wall and develop its flats quickly, yet strong enough not to bend in
normal use at 140 grams tracking force. As I have detailed earlier, harder
materials are not desirable for acoustic reproducers.
Fiber, cactus, and similar needles have never been a good idea, in my
estimation. They are MUCH too soft and develop their shoulders that ride on
the record land within one half of a record side. Thereafter, the needle is
not supported and guided properly by the groove and mistracking results.
That makes bad audio, even if the record is not being damaged. I don't know
how some modern materials such as carbon fiber might work. If you can make
them behave like the "ideal" needle mentioned above, then they would be just
the nutz.
Greg Bogantz
----- Original Message -----
From: "Jon Noring" <jon at noring.name>
To: "Antique Phonograph List" <phono-l at oldcrank.org>
Sent: Saturday, February 09, 2008 6:33 PM
Subject: Re: [Phono-L] Victor versus Columbia big guns
> Greg wrote:
>
>> That, by the way, is why sapphire needles, together with the
>> decreasing
>> compliance in the hardening rubber suspension bits of the old crystal
>> cartridges of the 1930s have wreaked so much damage on records from that
>> period. You may have noticed that your 1930s vintage records sound more
>> worn out than your teens and 1920s records. The reason is that the
>> "record
>> grinders" of the 1930s chewed the crap out of records with their sapphire
>> needles tracking at 30 grams whereas the steel needles of the teens
>> developed their flats much faster and didn't chew up the records so
>> badly.
>
> Thanks for the informative message!
>
> This brings back the next question I have.
>
> Ignoring for the moment the strength requirements of the needle, what
> would be the ideal properties for the tip material?
>
> One can imagine coating or tipping a tungsten needle with this other
> material ("idealium") so as to combine the strength of the titanium to
> transfer the audio energy (and simply not to bend under the weight)
> with the ideal properties of the material in direct contact with the
> record groove.
>
> Of course, we want to minimize record wear, get good tracking, etc.
>
> (This is reminiscent of what Columbia did with laminated records.)
>
>
> I also recall that the use of "fiber" needles -- would the use of
> anisotropic fiber materials for the needle possibly confer desired
> properties? Today we have carbon fiber, kevlar, etc.
>
> Jon Noring
>
>
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