Many times the pros and cons of playing shellac discs on wind-up phonographs have been discussed here on this list. There are more than a few collectors who are completely convinced that if you follow the rules, no damage occurs to your records whatsoever (I even know of an eBay seller who admits to playing ALL his records on his wind-up for aural grading purposes, complete with a diatribe in this practice's defense, though he'll never convince me to buy one of his items), and outside of phono maintenance, there really is only one rule -- use a new needle every time, period. I have never agreed with this. I'm a child of the 80's, and I remember when CD's came out -- one of the selling points (though quite secondary to the issue of surface noise) was that you cannot play a record with some miniscule amount of damage, but that you cannot inflict any amount of damage on a CD by playing it no matter how many times you do so. (And remember, they were talking about modern vinyl records with lightweight tonearms and meticulously ground stylii, not a headless nail with a half-pound chunk of metal sitting on it.) It's absolutely true, as anyone who has ever fallen asleep during play of a modern LP on a modern, non-automatic turntable can attest, as they will hear what sounds like pink noise coming from the closed groove near the label, and a certain amount of black vinyl dust wil find itself on their stylus. Further proof: I have a very nice audiophile turntable rig (Music Hall MMF-9 with lots and lots of upgrades, Shure V15VxMR cartridge), and every time I change the stylus, I let it run in one of the locked-groove white noise grooves of the Cardas Frequency Sweep and Burn-In Record for at least a few hours (usually more like 5) before doing any serious listening. And if you go through my disc's tracks one by one, you will plainly hear a couple that have been used more than once, as evidenced by 3 to 6 dB decrease in the treble frequencies. But back to wind-ups. The idea behind the steel needle/diamond dust in the shellac system is that at the beginning of the record, the first few grooves of (hopefully) dead air will grind the surface of the needle to custom fit that particular groove. My expanded idea of this is that once the needle is sufficiently ground to fit, the grinding of both the needle and the record are reduced drastically, as the weight of the soundbox is then supported by the maximum amount of contact area between needle and groove; if this is true, then an ideal constitution of shellac and diamond dust could be arrived at, as the amount of grounding necessary could be calculated to a very fine degree. So what's the problem? Azimuth. The soundbox travels at a curve. And to compound the problem, tonearms were largely kept at a relatively short distance, something like 170mm compared to the 233mm of a modern tonearm. The length of the tonearm is one of the things directly responsible for the reproducer's perpendicularity to the tangent of the groove at the needle's contact point. I don't have a protractor with which to measure the degrees of arc the soundbox of my portable Victrola is subjected during full transverse of a disc, but believe me, it is sadly substantial, visually. Here's a non-scientific test: grab a small square and align one leg against the inside of the soundbox, with the other leg vertically aligned with the horizontal center of the diaphragm while in playing position (for another non-scientific test, line that leg up directly above the needle's contact point), at the start of a record and then at the end, and see for yourself how much the soundbox's relative position to the groove tangent rotates. (As a point of reference, if the square were arranged with the leg pointing at the spindle, it would continue pointing at it throughout the needle's travel if the angle of the soundbox to the groove tangent was consistent.) It is, in a word, severe. This necessarily means that the walls of the needle as ground flat(ter) by the first few grooves of the record are only in line with those first few grooves. What happens throughout the record is the same thing that would happen if you rotated the needle in the shank slightly and played those first few grooves again -- substantial damage to your record. The truth is that the whole "grinding the needle for the first few grooves eliminates further damage" theory is complete and total bunk. If your tonearm isn't at least 100 feet long, that record is getting gouged the whole time you're playing it. Engineers who design modern turntables, with tonearms more than 30% longer than those of many wind-up phonographs, still consider azimuth a chief design compromise. Granted, with modern tonearms, it's not as much about record damage as it is about the stability of the stereo soundstage and a number of other playback criteria, but the physics of the thing remain: they STILL can't get it 100% "right." (Forgive the oversimplification; the point stands.) So who DID get it (kinda) right? Three guesses: That's right. Good ol' Tom. He knew the deal. Due to the travel of the back of Edison's DD tonearms as the record progresses, the effective length of his tonearms is astronomical in comparison to pivot-hinged tonearms of other phonographs, while the tonearm length itself, and its volume/tone characteristics, are essentially the same. A DD reproducer's angle while traveling across the top of a Diamond Disc isn't perfectly still, but it's WAY closer than a Victor Ortho's (for example). And to make it even less of an issue, if I'm not mistaken, Edison's permanent diamond tip was perfectly conical, offering exactly the same profile to the disc's grooves, regardless of the angle of the soundbox. (Gotta give it up to Pathe for using a version of this design concept as well.) But then, we all know that no matter how die-hard a collector's conviction is that no groove damage occurs from wind-up playback, it's not often we see any of them playing Caruso Zonophones and the like on their Vic VI's. Thoughts? Comments? Corrections? It has been quiet in here for a while, indeed! Best to All, Robert