I think the "ringing" of the Edisonic Reproducer is due to the vibration of
the weight, acting like a bell, being transmitted to the stylus bar & thus
to the diaphragm by the spring, not by vibrations generated by the spring
itself.
Jim Cartwright
jimcip at earthlink.net
EarthLink Revolves Around You.
> [Original Message]
> From: Greg Bogantz <gbogantz1 at charter.net>
> To: Antique Phonograph List <phono-l at oldcrank.org>
> Date: 5/8/2008 2:47:39 PM
> 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" <lherault at bu.edu>
> 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
> > _______________________________________________
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> > http://phono-l.oldcrank.org
> >
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