How do you know that they will not be valuable in the future? Remember, at one time the Vic VI and Edison Alva were considered junk. Well, grasshopper, do you want to take that chance?
Thatcher Graham wrote: > That begets a question for me. How do I know what 78s in my collection > are valuable? From [email protected] Fri Mar 7 15:22:04 2008 From: [email protected] (Greg Bogantz) Date: Fri Mar 7 15:36:44 2008 Subject: [Phono-L] Shellac records and damage from steel needles References: <[email protected]><[email protected]><[email protected]><[email protected]><002f01c87fce$5ee3b130$6400a...@hpa1514n> <[email protected]> Message-ID: <006201c880aa$0e201b80$6400a...@hpa1514n> Robert, I have to think that the peculiar tonearm arrangement that Edison came up on the DD players with was done for a combination of cost and patent infringement reasons. This was his typical motivation since Victor and Columbia had already patented most of the early geometries and build details of early phonos. Good grief, hooda thunk that Victor could get away with patenting something as obvious as doors in front of the horn opening? They probably also tried to patent the wheel, but couldn't quite stretch their luck that far. But Edison had to contend with highly litigeous competitors, particularly with regard to his phono products because he was late to market with them. The peculiar tonearm pivot probably did not infringe on a current Victor/Columbia patent. He HAD to use the feedscrew arrangement to get around the Victor patent that covered a record-driven tonearm. Did you know that Edison mounted his DD motorboards with three-point mounts to the sides of the cabinet because Victor had patented the wood motorboard? Did you know that Edison had to mount his horn onto the moving portion of the DD player because Victor had patented the idea of a horn mounted to the cabinet? Whatta pain in the ass those patents must have been to him. Yes, he could have used a pantograph design to provide less LTA in his design, but it would have been more costly and he saw no need for it. As we've already established, LTA had no substantial effect on the reproduced sound, so Edison ignored it. He ignored LTA at least until the introduction of the long play DD. You may have noticed that the LP reproducer is twisted so that the reproducer weight and pivot is angled away from the line of the output tube. Edison had to do this because the excessive LTA of the original DD design caused too much skating force at the end of the record which caused the stylus to skip out of the exceedingly shallow and narrow grooves of the LP. The LP DD was the last gasp of a dying technology. It really was never ready for market, and its introduction further degraded the Edison reputation in the marketplace because the system worked so poorly. Even by today's vinyl LP standards, the outrageously fine recording pitch of 450 lines per inch (LPI) is just barely doable with any degree of reliability. (The average pitch of a typical LP is around 200 LPI, much the same as the standard DD. Or BA. Yes, Edison invented the microgroove record WAY before postwar CBS Records was even a twinkle in British Columbia's eye.) To even THINK that this fine pitch, combined with a very shallow depth could be tracked by an acoustic reproducer tracking at around 70 grams just boggles the mind. Today, I wouldn't even consider trying to play an Edison LP DD with the original reproducer. To do so is to commit murder on the record. Greg Bogantz ----- Original Message ----- From: "Robert Wright" <[email protected]> To: "Antique Phonograph List" <[email protected]> Sent: Friday, March 07, 2008 8:54 AM Subject: Re: [Phono-L] Shellac records and damage from steel needles --- SNIP --- > Regarding DD's, Pathe's, and the virtual absence of LTA as a mitigating > factor, you have pointed out all the same things I've pointed out. I did > say that there is some error with the DD machines, but that it made no > difference to the playback characteristics. I didn't point out that the > arc was reversed, but it brings up an interesting point: Edison could've > easily included one more extension to the tonearm suspension that would've > given him bona fide linear tracking, i.e., zero lateral tracking error. > It is my belief that he knew this and chose not to, for a few reasons. > One, with a feedscrew driving the tonearm, it was not necessary to > optimize skate/anti-skate issues for playback reasons. Two (and this > one's a stretch), the reverse arc puts the lateral tracking error at the > end of the disc towards the outside (I'm not sure how to say this > correctly in technical terms), the way it is at the outside edge of the > disc on a standard back-pivot tonearm, increasing the amount of skate > force at the inside of the record -- certainly handy to ensure a quick > skate towards the label after the groove ran out to trip the Duncan stop, > though this would obviously have been an added bonus, not an initial > design function. But most importantly, it sounds like exposing a rotating > profile to the record when using perfectly conical or spherical stylii > would be a GOOD thing -- that while making no difference whatsoever to > playback characteristics, it offers a self-refreshing contact point on the > stylus itself, probably adding substantially to the life of the stylus. > It would certainly stand to reason. And with these two systems, we're > talking about a situation where the stylus is custom-ground for the groove > to begin with, that the fresher the stylus, the more contact area, so > giving the groove the freshest stylus profile possible across the record's > total surface seems like a real plus! > --- SNIP ---
