The Magnetic Cello (Simular to the Theremin Cello)

Posted: 9/21/2011 10:59:44 AM

From: California

Joined: 9/11/2011

wrote: Bob Moog never patented his Etherwave theremin innovations because the process was too expensive (about $10,000.00 in the 1980's). His ideas have been copied by others but the "niche" market for theremins is so small that the loss proved insignificant.

Hey coalport,
I'm not too worried about competition. I definitely have a niche market in mind. And Moog seemed to get along well with only one patent.

Actually, It would be nice to see people copy and improve off my idea. I'm not yet really good with electronics (I mostly copied the technical datasheet or got lucky with my choice of amplifier) and it would be interesting to see a really polished version or a version with other people's ideas build in, even if it not made by me. Also, the more open about the instrument, the more likely some is to actually pick it up. All I really need is the credit for what I've done so far, thus the provisional (not regular) patent.

By the way, just to make sure, do I understand correctly that provisional patent applications are published 18 months after they are filed? Where are they published?

Thanks again,
Posted: 9/21/2011 6:44:58 PM

From: A Coruña, Spain

Joined: 9/26/2010

Apparently, patent lawyers don't really know what the exact definition of prior art is right now, see:

[i]One element of uncertainty that will be created by this Act, at least for the next five to ten years, is the definition of invalidating prior art. Prior to this reform, decades of case law had been established to define what was necessary for prior art to be invalidating because it was “known,” “used,” “patented,” “described in a printed publication,” “in public use” or “on sale.” However, 35 U.S.C. §102, as amended, has introduced a new standard of “otherwise available to the public.” The statute does not define this phrase and it will take time for the Federal Circuit to sort out. While this Act has created some certainty as to what may qualify as invalidating prior art with respect to the invention date, it has introduced a new level of uncertainty as to what types or quality of publications or events may qualify as invalidating prior art.[/i]
Posted: 4/15/2012 7:06:44 AM

From: California

Joined: 9/11/2011

Hey guys,

Haven't been here in a while. Just wanted to let you know that the Magnetic Cello, my attempt at adding a new instrument to the list of playable, expressive electronic instruments, is done and that I'm taking reservations for the summer 2012 release. The Magnetic Cello is similar to the Theremin Cello, except instead of a lever, sound is controlled by magnetic induction. Check out for more info. Thanks for your support!

Posted: 4/15/2012 8:58:03 AM

Joined: 3/30/2012

Congratulations, that's some invention!

There seems to be an audible thump or whoosh at the start or end of some "bow" strokes. Is that a matter of bowing technique, or an unavoidable characteristic of the design?


Posted: 4/15/2012 10:52:54 AM

From: Theremin Motherland

Joined: 11/13/2005

Who is interested here's another (but not touchless) version  of the сello:

Posted: 4/15/2012 9:49:59 PM

From: Weert, Limburg, the Netherlands

Joined: 4/10/2012

I really like the magnetic cello ... Nevertheless I think it might be a well idea to improve it's sound (less sinus & old Commodore 64 like ;-) ), but more with fullness, maybe work with more oscillators? Anyway, the setup is great and I think you really can play like a cello on it!

At the other hand, I also miss some "egality" while you're playing, as it seems that the sound is getting less loud when you take more distance from the plate, isn't it? I know with striking snairs, the sound only gets less when you stop striking them ... Maybe you can find something out like that, as the volume (loop) antenna can work on both sides too ;-)

I think that these things are the only little minor things to work on, but for the rest, it's great!


Marielle :D

Posted: 4/16/2012 1:00:01 AM

From: Canada

Joined: 8/1/2008

The magnetic cello is an instrument in its infancy and as such it needs to be encouraged and supported. There is no doubt that if David Levi sticks with the project, the device will evolve rapidly into something quite different from what we see and hear today. It has already undergone many important transformations since the earlier prototype.

Let's not forget, the theremin was a flop when it was first introduced. RCA abandoned the project after only about a year, and it did not see the light of day again until Bob Moog single-handedly revived it decades later. 

As for Lev Termen's theremincello, it never got beyond the early stage of its development before it was discarded along with the terpsitone and the rhythmicon). So what was the problem?

An electronic version of an acoustic instrument, in order to justify its existence, must be easier to play than the instrument that inspired it, without sacrificing any of the unique qualities that people love and appreciate in the traditional sound. 

Is the magnetic cello easier to play than a traditional cello?

Can it play the traditional cello repertoire?

Does it have any advantages over an acoustic or electroacoustic cello?

When you hear it played, do you recognize the signature timbre and impact of an acoustic cello - double stopping, pizzicato, spiccato, etc.?

When you watched the video, did you say to yourself, "Gee, I wish I could play like David and his friends." 

Was there anything in the sound of the magnetic cello that you missed when you compared it to the more familiar acoustic cello? If so, was there some other quality in the sound that compensated for whatever you felt was lacking?

The cello evolved as it did, by way of the gamba, in order to accommodate the demands of bowing such a large instrument. The fingerboard faces away from the cellist primarily because there was no way to build a soundbox large enough to amplify and enhance the sound and still have the strings in a relatively "bowable" configuration while the fingerboard was visible to the player (as it is with the cello's smaller cousin, the violin). There are reasons why the cello is built the way it is.

The magnetic cello, on the other hand, does not have the same acoustic requirements and constraints, so is it logical to construct it with the same awkward design? Does it make sense to have a cello "skeleton" so the instrument can be clutched between the knees of the player with the fingerboard facing away? There are no strings, and there is no bow, so other than for pure spectacle, what is the purpose of the design? Is it ergonomic?

I don't know the answer to any of these questions, but I think both the builders and potential buyers of this instrument must ask them. 





Posted: 4/16/2012 3:24:50 PM

From: Northern NJ, USA

Joined: 2/17/2012

"In my humble opinion, the instrument maker really needs to focus on how the instrument is played, even before tone or novelty. The way it sounds and the options it has can be improved later, but you have to get the basic mechanics right first."

I agree, the ergonomics of controllers are 95% of it IMO.  Electronic instruments are especially freeing and difficult here because there are so many options.  Making a controller that behaves somewhat like an equivalent acoustic instrument allows the new players to transfer skills and so facilitates quicker adoption of the new controller, but it doesn't advance things much.

My particular focus is on controller design, with tight integration between controller and sound source.  It would be interesting to be able to "bow" a controller by coupling a transducer to a digital waveguide.  That way rubbing it would set up oscillations that would feed back to the transducer, much like a bow and string.

Posted: 4/16/2012 5:05:08 PM
RS Theremin

From: 60 mi. N of San Diego CA

Joined: 2/15/2005

When watching David Levi of Cal Poly “SoCal” demonstrating his work of art I think of it as a marvelous new instrument of his own design. It should not to be compared, the word cello might mislead us like Electro-Theremin.  David, let the project guide you into the future.  Your experiments are superior, especially in a generation that unfortunately thinks “circuit bending” is something special like creative music.

Good job, now about your gravity experiment…don’t blow up the earth!

Europe already has the Hadron Collider and those French men getting involved!!!


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