Echophone

[gregbogantz]

This strikes me as a perfect example of the "by guess and by golly" method of inventing. Tinkerers cobbled together all sorts of contraptions, some of which actually happened to work. When asked to describe them, the inventors really didn't understand what they had made (for example, DeForest never could correctly explain how his Audion vacuum tube worked).

In the case of reproducing the content of a phonograph record, just about any arrangement of stylus coupled to just about anything will make some kind of sound. This Echophone reproducer as originally described in the patent includes a weight to increase the tracking force rather than the spring used in the production models. The weight makes more engineering sense as it provides mass somewhere along the length of the glass tube. This mass acts like the fulcrum pivot along the needle bar of more conventional reproducers such as made by Edison or Victor. Or, even more similar to the fulcrum point of the long wooden needle bar of a Vitaphone tonearm. To be most effective, instead of being hung by threads at each end of its length (which produces a vague center of mass distributed along the glass tube), the mass should have been hung from a single point, just as the spring was attached in the production models. This arrangement would make more efficient the rocking motion of the glass tube around the fulcrum which would translate the vertical stylus tip motion to vertical motion of the back end of the glass tube which would then vibrationally compress the sandwich of the tapered rubber tubing and flat wooden clamping pieces, thus creating air pressure changes inside the tapered rubber tube.

HOWEVER, the production model with the tracking spring instead of mass seriously reduces the transmission of vibration as vertical motion at the back end of the glass tube. Instead, without the mass creating a virtual fulcrum pivot along the glass tube, the fulcrum point moves back to the end of the glass tube where it attaches to the pin in the wood. This results in the vertical motion of the stylus tip being translated to rocking motion at the back end of the glass tube rather than vertical motion. This is a much less efficient transfer of energy. The rocking motion of the pin on top of the wood clamp plate translates poorly to compressions of the air inside the tapered rubber tube. So the resulting sound made from this production model is probably pretty weak. I doubt that it would produce anything more than a whisper if attached to a horn, but it would probably be sufficient to hear with the listening tubes that were provided with the Echophone. Another "close, but no cigar" moment in inventing history.

[TinfoilPhono]

Over the past couple of years several people have asked me to upload a video of my Echophone to Youtube. This morning I finally got off my duff and did it: http://www.youtube.com/watch?v=ZARaIwtnvsA

I think you'll be as surprised as I was the first time I played it. It doesn't sound half bad, and it plays very steadily. And this is with an early brown wax cylinder. With a black wax record it's quite loud -- but of course this was obsolete long before black wax records became available.

[phonogfp]

Very nice, Rene. I couldn't help but smile as it played - - Echophones are fun to watch, and I haven't played mine in years. I'm tempted to run upstairs and do so right now... Thanks for posting!

George P.

[Starkton]

Doesn't the Echophone sound much better with earphones, as seen on the ad sent out by Leslie's Weekly in December 1896 (see my post on page 1 of this thread)?

[phonogfp]

Doesn't the Echophone sound much better with earphones, as seen on the ad sent out by Leslie's Weekly in December 1896 (see my post on page 1 of this thread)?

Absolutely! I think most brown wax sounds better with ear tubes, and a contraption like the Echophone definitely needs every advantage! That said, the reproduction through ear tubes is surprisingly good.

George P.

[TinfoilPhono]

No question about it. As George says, all brown wax sounds better through earphones. It's not as easy to show on homemade video, however. Despite the limitations of the horn, this demonstrationdoes manage to show that the Echophone plays quite well for such an odd and early machine. It would certainly be more impressive if you were to visit and hear it in person.

[phonohound]

I recently got out my wooden mandrel Echophone, all original, and brought it to a friend's house who also has an Echophone, but with a gutta percha mandrel. I brought it there to see if they could help figure out why my phonograph wouldn't play and compare it to theirs. After some lubricating and taking things apart, we determined the glass rod is about ½ inch too long. The stylus barely touches the record.

I am 100% certain my Echophone is all original, even the glass rod. I was curious if anyone else has this problem. How could it leave the factory with a glass rod that is too long? I'm stumped and was curious if anyone here might have some ideas.

Thanks much.

Scott

[AllenKoe]

Hi,

The Echophone was first shown on Amet's own personal stationery in late 1895 (as part of his return address).

The first models did not have the little coiled spring (to maintain continuous contact), but did have a small weight that hung downward from the glass tube (see the original patents). Not a great idea for a tone-arm that had a glass stylus.

It was thus very important for the first ones to be located on an absolutely level surface - this was accomplished by Amet installing a precise bubble-level in the wooden base("Keep Me Level"), and installing a vertical leveling-screw in the cast base to raise and lower the entire machine. Even later models still show the small metal 'plateau' on the frame through which the screw was originally threaded.

Rene did a very thorough article (illustrated) on this machine, and its history, in the CAPS magazine, some time ago.

Best
Allen
www.phonobooks.com