Has anyone ever tried slipping a bit of modern "rubber" tubing over the spring or maybe painting the spring with silicone sealant?
Ron L -----Original Message----- From: phono-l-bounces at oldcrank.org [mailto:[email protected]] On Behalf Of Greg Bogantz Sent: Thursday, May 08, 2008 3:47 PM To: Antique Phonograph List Subject: Re: [Phono-L] edisonic vs. dance? Ron L is correct. But both of these springs were bad ideas to begin with. They were a lame attempt to account for the escessive bias placed on the diaphragm by the extra weight which causes the diaphragm to be stressed (and strained) downward even more by the tension in the stylus bar link. The extra weight used in the Dance and Edisonic models was required to reduce mistracking and distortion when playing highly modulated records, particularly the later electrics. It DOES NOT make the reproducer play "louder", contrary to the bilge in the Edison blurbs to that effect. The loudness can only be controlled by changing the mechanical "gain" of the stylus bar which is the ratio of the stylus tip distance to the bar pivot relative to the distance from the bar pivot to the link. This ratio is the same for ALL Edison DD stylus bars, hence they all play at the same loudness. You can confirm this to yourself by using the different models of reproducer to play very soft recordings which do not tax the reproducers - they will all sound the same loudness. The fact that they may sound different when playing loud recordings is due to the differences in mistracking and distortion that they exhibit on those records. This biasing of the diaphragm is indigenous to the tracking of vertical modulation and is one of the several problems with that technology. (This problem does not exist with lateral reproduction.) Having a permanent bias or bend in one direction while playing a record causes the diaphragm to exhibit assymmetric nonlinear behavior (due to it nonlinear elasticity) which is yet another contributor to the generation of even orders (2nd, 4th, 6th, etc.) of harmonic distortion. Edison tried to reduce this bias (or permanent bending offset under playing tension) of the diaphragm with the addition of these springs into his later models of DD reproducers. There is a lot of bloviation about the purpose of the springs in his patent disclosure for the Dance reproducer, but compensation for the bias was their intended purpose. It didn't work. Mostly because he didn't account for the added spring constants these springs introduced into the diaphragm resonance which changes and/or adds to the mechanical resonances of the system. In particular, he didn't damp the springs sufficiently or at all. The diaphragm spring was designed with some damping in it, but it was ineffective. The stylus bar spring has no damping that I can find. Consequently, you can hear this spring "ring" when you play records. If you pay attention, you can hear a ringing noise behind the music which is this spring boinging or oscillating. Bad idea. My advice is to just remove both of these springs. The reproducer will sound cleaner and clearer with fewer resonances and extraneous noises. Greg Bogantz ----- Original Message ----- From: "Ron L" <[email protected]> To: "'Antique Phonograph List'" <phono-l at oldcrank.org> Sent: Thursday, May 08, 2008 2:07 PM Subject: Re: [Phono-L] edisonic vs. dance? >I believe one has two springs and the other has only one. I think the > Edisonic has the spring only on the needle bar and the Dance has one on > the > diaphragm as well, hence the bolt-on neck. > > Ron L > > -----Original Message----- > From: phono-l-bounces at oldcrank.org [mailto:phono-l-bounces at > oldcrank.org] > On > Behalf Of Peter Fraser > Sent: Thursday, May 08, 2008 1:46 PM > To: Antique List Phonograph > Subject: [Phono-L] edisonic vs. dance? > > can anyone expound on the differences between the Edison Dance > reproducer and its successor, the Edisonic? As near as i can tell, > it's just the bolt-on neck...but does the little spring have different > characteristics? is there anything else? do they sound appreciably > different when equally restored? > > thanks for anything you can offer... > > -- peter > _______________________________________________ > Phono-L mailing list > http://phono-l.oldcrank.org > > _______________________________________________ > Phono-L mailing list > http://phono-l.oldcrank.org _______________________________________________ Phono-L mailing list http://phono-l.oldcrank.org
