The Talking Machine Forum — For All Antique Phonographs & Recordings

I think there was an attempt to design this to avoid patents held by others. The coupling between the sound-box and the horn, being of constant cross section surely introduced some deterioration of the sound. The wood stylus bar is indeed just an enlongated stylus bar operating on exactly the same principle as a conventional sound box. The difference in mechanical advantage, as well as the damping effect of the wood itself would probably cut off higher frequencies. I wonder if most people played it with the top down, or raised?

I think most Vitaphones were so designed that you could not leave the top up while playing.

Mine will play with top up or down, but sounded much better with the "plumbing" disconnected & an Edison cygnet horn attached. It also needs new gaskets & the spring seems to be broken or disconnected, so hasn't been played for almost 20 years!

All the Vitaphones with internal horns in the lids that I've seen are designed with complex multi-jointed plumbing to allow the lid to be either open or closed while playing. Keen-o-phones, on the other hand, did not use the elaborate plumbing, and the lid was required to be closed to complete the coupling of the tonearm to the horn. "Needle talk" (sound directly emanating from the diaphragm or stylus assembly) is somewhat less than you get from a conventional acoustic reproducer, largely do to the diaphragm being tucked in the back of the player compartment. But there is a noticeable difference in the sound depending on whether the lid is closed or open. These machines are pretty inefficient acoustically, compared with conventional internal horn designs. The wooden stylus bar is MASSIVE and flexible by comparison with the standard stylus bar, so there is a lot of loss of acoustic energy along the way. This mass along with the natural damping of the wood reduces the treble considerably. As a result, these machines play rather softly but without the honky midrange that is typical of the conventional designs. Overall, the sound is pleasant. But the compliance of this arrangement is next to zero, so using a thick "loud tone" steel needle in a Vitaphone is a sure way to grind the bejeezus out of your records. The efficiency of the diaphragm connection is even less when playing lateral records, so these machines sound best when playing verticals. Equipped with a Pathé sapphire point, these machines sound best when playing Pathé sapphire discs.

Quite right Greg, I confused them with the Keen O Phone

<<<the compliance of this arrangement is next to zero, so using a thick "loud tone" steel needle in a Vitaphone is a sure way to grind the bejeezus out of your records.>>

Not sure I'd even feel that safe using a soft needle with all the mass the needle has to move around, compared to something like an orthophonic that in comparison is moving next to nothing, besides the diaphragm. Then the volume and high notes would suffer even more. I'll say this for it though, it is definitely different, I like weirdness.

So if the string is what is pulsing the diaphragm, doesn't that mean it is only transmitting the energy of the grooves' undulations in one direction, as opposed to a soundbox which moves the diaphragm equally in both directions? I.e. viewing the grooves as sine waves, is it chopping off the bottom of the waves? Maybe that could be a factor in the lower volume. Sounds like the string is pulling on the diaphragm but obviously it can't push on it as well. (?) I'm just sort of guessing, going by the descriptions and the photos.

Marky, your analysis would be correct if there were no mechanical bias on the diaphragm. When the spring arrangement is positioned for vertical records, i.e. the spring thread is unhooked from the diaphragm stanchion, it pulls down on the diaphragm. In this condition, the stylus bar plus the spring thread tensions add to cause a constant pull on the diaphragm when the needle is sitting on the record in the same way that an Edison DD reproducer works. This bias is RELIEVED by record modulation valleys that allow the needle to drop downward, causing the diaphragm to move upward and return closer to its unbiased condition. Opposite modulation peaks that force the needle upward ADD to the constant bias and further deflect the diaphragm farther downward. Hence, both peaks and valleys in the vertical groove modulation result in corresponding diaphragm motion.

When playing lateral records, the bias spring must be positioned over the hook in the stanchion on the side of the diaphragm. This puts a tension on the diaphragm which pulls it sideways and somewhat awkwardly downward at an angle, rather twisting the diaphragm on its axis. Since this bias caused by the spring is mostly sideways, this bias tension is either RELIEVED or ADDED to by the sideways motion of the stylus bar when playing lateral records. Once again, both the left and right motions of the needle result in corresponding vertical motion of the diaphragm. The system is obviously imperfect, but it works after a fashion. As I said earlier, this arrangement for playing lateral records is less than optimum and the arrangement for playing verticals is much more ideal which is why the Vitaphone works better when playing verticals than laterals.

<<When playing lateral records, the bias spring must be positioned over the hook in the stanchion on the side of the diaphragm....Since this bias caused by the spring is mostly sideways, this bias tension is either RELIEVED or ADDED to by the sideways motion of the stylus bar when playing lateral records.>>

OK thanks for explaining that!
Marky