Hmmm, Jon, sounds like yer asking to have yer cake and eat it, too. A material soft enuf to wear into conformance with the groove quickly would just continue to wear. If it was a tip coating of some sort, then it would wear away, pretty quickly exposing the underlying firm needle material which would then commence to wear itself away, thereby grinding up the record in the process until it developed its own flats. You don't want the material to be soft and elastic. To be so would fail to convey the groove power to the needle shank - the elasticity of the needle tip would yield instead. This might be tolerable during a break-in period, but you wouldn't want it to remain that way or you wouldn't get any loudness from your playback. Teflon and similar slippery materials might be interesting to play with, but most of these materials are too elastic, in my experience, for this application. I'm not up to date on my modern materials, but I can't imagine a material that is stiff enough with a 5 mil cross-section at the groove not to flex under the loading of the heavy reproducer, yet retain high lubricity at the groove wall for an extended number of playings. Remember that shellac record formulations contain limestone, clay, or other abrasive filler, the purpose of which was to wear the needle into conformance with the groove fairly quickly so as to reduce future record wear. These very abrasives would probably play hell with even slippery materials used on needle tips. 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 7:51 PM Subject: Re[2]: [Phono-L] Victor versus Columbia big guns > Greg wrote: > >> As I said in the earlier response, the tip shape of the tungsten wire >> is >> irrelevant. It conforms to the record groove in a matter of seconds when >> first used. You just have to be aware that it is gouging the crap out of >> your record while this is happening, so you want to use a junk record >> during >> this shaping period. The harder the material used in the needle, the >> longer >> it will take to shape it to the record groove. So modern harder >> materials >> will probably never be a practical solution. And the problem of tonearm >> tracking angle error further adds to the likelihood that a super-hard >> needle >> would always be gouging your records even after it develops its flats. > > Actually, I was thinking of two different approaches to the tip > material: > > 1) Something that would wear away quickly and in a way that does > minimal wear to the groove. Let the tungsten needle provide the > stiffness and transference of the audio energy, and let the tip > material have the optimal wear characteristics. (We can think of > non-metals, and metalloids such as silicon and germanium.) > > 2) Something that would adapt to the groove in a non-wear sense, such > as a slightly elastic plastic. How would a teflon tip do? > > In reality, one can't avoid wear, but the "elastic tip" is certainly > intriguing. Teflon and similar fluorocarbons can have low friction and > elasticity. > > I think we should not accept the need to "break in a needle on a junk > record" as a given -- let's see if we can think outside the box and > avoid having to do this... > > Jon Noring > > > > > > > > > > > _______________________________________________ > Phono-L mailing list > http://phono-l.oldcrank.org